#1 Gut Health Doctor: "If Your Poop Looks Like This, Go To Your Doctor!" Dr Emily Leeming

Dr. Rangan Chatterjee 0:00 How might any one of us know if we have excellent gut health or poor gut health?

Dr. Emily Leeming 0:07 So most people might think, "Oh, I need to go and have a gut health test." But actually, what a gut health test is gonna tell you is just what microbes that you have, and perhaps how diverse those microbes are. So we talk about a healthy gut microbiome as one that contains a range of different types of microbes, similar to a company that has lots of different jobs. You don't just want a company with a marketing department, you also need HR, and you need, uh, product developers, uh, and you need a PR team, and probably someone to organize some work drinks for some fun. Um, your gut microbiome needs all these different, uh, kind of jobs as well. But the thing is, a gut microbiome test is incredibly expensive, and isn't gonna tell you much more than that. It's not gonna give you any actionable advice.

Dr. Rangan Chatterjee 0:50 Yeah.

Dr. Emily Leeming 0:50 So actually, the real thing that you can do, which is completely simple, easy, affordable, free, is just look in the toilet bowl, and look at your poo. Uh, I talk about, uh, poo a lot, because really, it's a, such a great sign of telling you how healthy your gut is, and how healthy your gut microbiome is. Because a significant portion of your poo is made up of the bacteria that's kind of dead, some still living, that is coming from your gut microbiome. So what are the key things we want to be looking for?

Dr. Emily Leeming 1:20 We want to make sure that you're going between three times a day to three times a week. That's quite a broad range.

Dr. Rangan Chatterjee 1:26 Yeah.

Dr. Emily Leeming 1:27 But anywhere within there, that's normal for you. You want it to look like a smooth sausage or a sausage with cracks in it.

Dr. Rangan Chatterjee 1:34 Okay.

Dr. Emily Leeming 1:35 And also have it to be a kind of brown, dark brown color. Red flags would be things like having blood in the stool, whether that's coming up as being black or kind of red. That's something where you might wanna go and get that checked out, and just see if there might be something else going on with your doctor.

Dr. Rangan Chatterjee 1:51 So this is really interesting. Okay, so you're saying that basically a lot of these gut health tests that exist today, these commercial tests, probably aren't gonna tell you that much. The best way that we can all do is look at our stool, basically, and you're saying that there's a range. Now, that... What was interesting about that range is that it's huge, right? Three times a week, you know, opening your bowels, to three times a day is a huge range, isn't it? Do you think sometimes people feel, "Well, I'm only going three times a week, that must mean I'm constipated." Whereas you're saying, certainly from that, that that could be just your normal?

Dr. Emily Leeming 2:37 Yeah, I think we, we really think about what is, what is your usual, if you're within that range. If you have a change from your usual, that could be the sign of a problem. So even if perhaps you're within that healthy range, and you're going more often, and then you suddenly start going much less, that could also be a sign that perhaps there's not something going s- on that's, that's quite so healthy. And I think also when we're talking about the health of, of your gut microbiome, it's not just about the health of your kind of gut, and which is a really... You know, your poo is a really great sign of being able to see how healthy your gut is. It's also how you feel, and I think we've really got to recognize that health is every single day of your life. It's not just about, you know, trying to ward away some kind of future illness. Um, of course, that's still really important, but I really want to kind of bring back this conversation to health being about how you feel right now. It's your energy, it's your mood, it's your cognition, and those pieces of the puzzle every single day is then making up that picture of your health throughout your life.

Dr. Rangan Chatterjee 3:40 Yeah, I love that. Absolutely love that, Emily, and I think it's a really great point. Let's go back to that range of bowel opening, 'cause I think if, let's say, you're only going three times a week, and yes, that may be in the normal range, but if at the same time you're feeling uncomfortable, you feel like you need to go, but you can't go, then even though that's technically in the normal range, it's probably not ideal for you.

Dr. Emily Leeming 4:09 Absolutely.

Dr. Rangan Chatterjee 4:09 Do you know what I mean?

Dr. Emily Leeming 4:10 Yeah.

Dr. Rangan Chatterjee 4:10 It's like it's trying to bring those two things together. Yes, use a scientific, uh, table, for example, to help guide you, but then correlate that with how you feel. You know, what's your bloating like perhaps? What's... You know, how do you... Do you feel light? Do you feel heavy? Do you feel full? Those things are really important as well, aren't they?

Dr. Emily Leeming 4:28 Yeah, I completely, and I think we've got to think about, you know, how easy is it for you to go to the bathroom? Is it causing any pain? Is it causing discomfort? Those are also things that, you know, want to kind of maybe perhaps explore further.

Dr. Rangan Chatterjee 4:40 People often don't wanna talk about this, I guess, but it's so important, isn't it? How easy, in your view, should it be for someone to open their bowels when they go to the toilet?

Dr. Emily Leeming 4:51 It should be really easy. It shouldn't take that long. It should be something that, um, you know, you don't have to push, strain. It shouldn't be causing any pain. It should just be something that just feels very intuitive, it's happening, and you feel that everything is then completely out at the end as well.

Dr. Rangan Chatterjee 5:07 So that's what it should be. In your experience, how many people or what percentage of the population are able to open their bowels like that?

Dr. Emily Leeming 5:20 So I think, you know, I think it's quite surprising how many people are classified as having constipation. So I think that's about ranging anywhere between 20 to 40% in the statistics.

Dr. Rangan Chatterjee 5:30 Wow.

Dr. Emily Leeming 5:30 But actually, if we think about it, that everybody at some period of their life will have symptoms of constipation, and perhaps maybe not be completely constipated in terms of not going, you know, that often, um, but still struggling with some aspects of, of going to the bathroom. And I think we really need to be talking about this. We've got such a taboo around talking about... Like, I very much feel very strongly that we should say the word poo, because that's the word that we use, and I don't want to go around saying the word stool or, you know, bowel movement or, you know, let's just call it what it is.

Dr. Rangan Chatterjee 6:01 All right, let's do it.

Dr. Emily Leeming 6:02 You know, let's just say it.

Dr. Rangan Chatterjee 6:02 Let's, let's go with the word poo.

Dr. Emily Leeming 6:03 [laughs]

Dr. Rangan Chatterjee 6:04 Okay. Right. So, um- It's interesting. I, I completely agree with you. I think we need to talk about this more, okay? Because if we don't, we're not gonna know what is normal. We're not gonna start paying attention to what is that. I mean, on another note, this whole thing of paying attention, it's quite striking these days for me that many people cannot actually go to the toilet anymore to have a poo without their phone. Okay, which is really interesting. I'm not necessarily judging that or criticizing that, I'm just saying it's, it's interesting 'cause if you're trying to pay attention to how certain things feel with your health, if you're distracted whilst you're engaging in those things, whether it's, um, anything, you know, it's not just going to the toilet, then you may not be picking up on the signals, right?

Dr. Emily Leeming 6:52 I think it's such an important point that we need to be, you know, paying attention to what those feelings are, those urges, and really respecting those urges. So if people who are struggling with going to the bathroom and doing a poo, you know, it's really being in tune with those urges. Don't ignore them, 'cause that can make matters worse. Another really great tip is actually making sure that your kind of knees are with kind of, um, are propped up on a what, what we can call a poo stool, right?

Dr. Rangan Chatterjee 7:19 Yeah.

Dr. Emily Leeming 7:19 Um, that just helps to straighten up your kind of back end to make that poo come out much easier. In terms of food, um, there's actually some really great evidence around having two kiwis a day, and that's because it's so rich in fiber, a particular type of fiber that really helps to kind of smooth things through so you've got a smooth exit into the toilet bowl. And there's a few... You know, there's many other things that you can do. Most, most of the, uh, issues that we have with being... problems with poo and constipation, diarrhea can be ha- solved with easy, simple diet and lifestyle changes.

Dr. Rangan Chatterjee 7:54 Yeah.

Dr. Emily Leeming 7:54 And then of course, if you're having issues, please do go explore that with, with your doctor and your GP as well.

Dr. Rangan Chatterjee 7:59 Yeah. Well, we're gonna get into all the practical things shortly in this conversation. So let's go into, you know, what a lot of your research has been, all the research you put in Genius Gut, your new book, right? Let's talk about that. And I guess, you know, we're talking about gut's health, and we're gonna talk about how many different things affect our gut's health, not just our diet. One of the reasons I think many people struggle to go to the toilet these days is, is because of chronic stress. So can you talk about the relationship between chronic stress and our gut microbiome, and perhaps our ability to have a poo?

Dr. Emily Leeming 8:39 Yeah, absolutely. So stress is something that, you know, for many of us it's just part of life, right? There's... You know, we're all gonna come across something that's stressful. Um, little bit of stress, absolutely fine. It's, it's healthy for you. It's ha- what makes you, um, perform well in exams, um, and then your body goes back down and recalibrates back to normal. When we're getting... And so f- for some people, that can cause, just that small amount of stress, that, that spike, can cause them issues. They might... You know, I'm sure everybody knows someone or maybe experienced it themselves, they need to run to the bathroom, um, they've got perhaps diarrhea, or they can be constipated. It can be either way. That can also happen with chronic stress, so stress that is just consistent, consistent high levels of stress that is then impacting, um, how their digestion is working. The reason that's happening is because our body goes into what we call fight or flight mode, and that is where, you know, going back to kind of caveman days, we are needing to shut down the processes in our body that aren't essential if we need to run away from a tiger and save our bacon, effectively. Um, we need to put all that energy into our muscles. We need to be running away. Um, and therefore, our digestive system doesn't get as much blood flow as it perhaps normally would. There's also this very, uh, powerful connection between your gut and your brain, so much so that we call your gut your second brain, because they're physically connected through a long, wandering nerve called your vagus nerve. Now, this vagus nerve acts like a two-way pathway between your gut and your brain, and we think... We know that your brain is effectively the CEO of your body, but your gut is very, very chatty too, and actually 90% of that chat between, um, your gut and your brain is coming from the gut.

Dr. Rangan Chatterjee 10:32 Now, that's interesting, right?

Dr. Emily Leeming 10:33 Yeah.

Dr. Rangan Chatterjee 10:33 So you're saying there's this gut-brain highway.

Dr. Emily Leeming 10:36 Yeah.

Dr. Rangan Chatterjee 10:36 It goes both ways.

Dr. Emily Leeming 10:37 Yeah.

Dr. Rangan Chatterjee 10:39 But it's not going both ways equally. 90% is going from your gut to your brain, therefore we can conclude only 10% is coming from your brain back down to your gut.

Dr. Emily Leeming 10:49 I mean, so much communication is happening. You know, you've got your brain as this, the CEO. It's, it's managing what's, what's going on, but it also needs to have constant feedback coming back to its kind of central authority. But your, your gut therefore is then incredibly reactive to when things, like, happening with stress, and we see this with your gut microbiome as well, that your gut microbes, if you've got, you know, a healthy gut microbiome, are able to actually help you manage some of your stress levels. The thing is, what happens is that it acts a little bit like an elastic band, that if it's stretched too often, for example, if you're getting stressed consistently again and again and again, that relationship can actually end up going the other way and becoming problematic, because those molecules they're producing ends up being, um, kind of actually exacerbating perhaps your stress response. And this is kind of early emerging science that we're seeing this kind of modeled in mice, and then seeing this kind of in human studies where we see kind of links happening between people being more stressed and having, uh, a kind of less diverse and less healthy gut microbiome. Um, and we see in mice, for example, that two weeks of constant stress is enough for them to have a significantly different gut microbiome.

Dr. Rangan Chatterjee 12:04 Wow. I think people intuitively, if they think about it, understand that there's a gut-brain connection, that- ... physiology and psychology are intimately related. You cannot separate the two. What's interesting for me though is, how much of this communication back from our gut to the brain is mediated through our gut microbiome? Because some of it, I guess, is just through the vagus nerve, but I guess some of it will be from the metabolites made by the gut microbiome, which then go via the vagus nerve as well to the brain. Is that how it works?

Dr. Emily Leeming 12:43 Yeah. So there's a multiple different ways that your gut microbiome is talking to your brain and influencing your brain. Again, this is really exciting kind of early research that we've only really started to kind of tap into in the last couple of years. What we're seeing is that, yes, we've got this communication. The most direct communication is through the vagus nerve. That's... We think about that, that's like picking up the telephone to have a direct call. And then we've got the molecules, those metabolites that are produced by your gut microbes. They can also influence your brain. A great example of those are short-chain fatty acids that, uh, your gut microbes can... Only your gut microbes can make these short-chain fatty acids. Your body is not able to make it themselves. They make them by feeding on fiber from the food you eat, and these short-chain fatty acids have an anti-inflammatory effect, but they're also really important for your blood brain barrier. This is a protective fortress around your brain that effectively has gateways in it that stop anything that's problematic, like toxins or, uh, kind of harmful molecules from getting in. But it also needs to be staying strong and healthy to let in those nutrients that your brain needs. So that's an example of, of metabolites. Your microbes are also in tune with your immune system and signaling to your brain through your immune cells as well. Um, so that might be changing shape in different formats, perhaps like sending a letter in the post where you give it to the postman and then it maybe goes to a few different sorting offices and then ends up at your door. Um, that is also another way, pathway that your gut microbes are signaling to your brain. And then last but not least, we see this relationship with neurotransmitters, and h- your gut microbes, um, early signs that they're helping to supply your brain with the building blocks that your brain needs to make things like serotonin, your happy hormone, and also dopamine, which is your kind of, "Ooh, I like it, do it again," uh, neurotransmitter.

Dr. Rangan Chatterjee 14:44 Okay. This is fascinating. So let me try and summarize it the way I heard it, and you can tell me if I've got this right or not. Okay, so we've got this gut-brain access. There's communication from our gut to our brain and back from our brain to our gut. 90% of that communication is going from our gut to our brain, but it's not just one thing. We can think about it as maybe, from what you said, and, of course, the research is early and we'll learn more in the coming years, but let's say there are four different motorways going to the brain. One of those motorways is via the vagus nerve. We're getting messages from the gut to the brain. Another one of those motorways is, um, through the microbiome. The gut bugs are eating the fiber, let's say, that we're eating, making short-chain fatty acids like butyrate. So the butyrate is taking a different motorway to get to the brain to have anti-inflammatory effects. You're also saying that it can be via the immune system, so the gut bugs interplay with the immune system, and those signals get sent by highway number three up to the brain. And if I recall it right, highway number... Not a highway. I've been in America for two weeks.

Dr. Emily Leeming 15:53 [laughs]

Dr. Rangan Chatterjee 15:53 That's why I'm saying highway. Motorway number four might be that the gut itself directly is making neurotransmitters like serotonin or something like dopamine, and those are taking perhaps a different motorway to get to the brain. Is that roughly accurate to what you just said?

Dr. Emily Leeming 16:15 Yeah, so roughly accurate. Obviously, we're... This is incredibly complex, and I think we're breaking it down to those four pathways. Absolutely.

Dr. Rangan Chatterjee 16:20 And there could be 100 pathways.

Dr. Emily Leeming 16:22 Yeah.

Dr. Rangan Chatterjee 16:22 Right?

Dr. Emily Leeming 16:22 Yeah, yeah. Could be 100. There's, there's so many different things going on. But I think-

Dr. Rangan Chatterjee 16:25 But the basic principle?

Dr. Emily Leeming 16:26 Basic principle, absolutely. Absolutely. It's, you know, you've got the neurotransmitters, immune system, metabolites, those molecules, um, and you've got that direct pathway, which is the vagus nerve. I think the really interesting one which I find is talking about this piece around the neurotransmitters. So I don't know whether you've seen this. It's all over Instagram. I see that it's anything related to this topic. It's kind of, you know, 90% of your serotonin is made in the gut, and I always slightly kind of, like, grit my teeth a bit at that because in a way it is true, but the insinuation there is that that ty- that serotonin is actually influencing your brain. Um, let me just unpick that, why that isn't actually quite the truth.

Dr. Rangan Chatterjee 17:06 Okay, great.

Dr. Emily Leeming 17:07 Um, so yeah. So serotonin is, you know, we talk about it very simplistically as being our kind of happy neurotransmitter that is-

Dr. Rangan Chatterjee 17:14 Yeah

Dr. Emily Leeming 17:14 ... used in our brain. But serotonin is also, like many other molecules in our body, used for many other different things that's not just kind of mood related. Uh, so your gut microbiome and your gut make serotonin. Yes, 90% of serotonin in your gut. The thing is, that serotonin is too large a molecule to fit through that blood brain barrier, so it cannot pass into the brain to influence your mood. The role it's playing is it's actually helping with your digestion. It's helping your body to, um, the muscles to move, to move the food kind of through your gut. It's playing still a really important role. So what your microbes are actually doing is helping to supply and manage, uh, what the building blocks of that serotonin is. So tryptophan, which is an amino acid, is used to... and convert into serotonin. It's, it's a building block that's made into serotonin, but it needs to be supplied to your brain first because it's a smaller molecule, so it can fit through that door, that gateway-

Dr. Rangan Chatterjee 18:15 Mm-hmm

Dr. Emily Leeming 18:15 ... from your blood brain barrier. And then your brain can make serotonin, uh, in the brain that's gonna influence your mood. So we think that is the relationship

Dr. Rangan Chatterjee 18:26 Yeah. Thank you for clearing that up. So can we say therefore still though that although the serotonin made in the gut may not actually be the serotonin that gets into the brain, can we still say that actually feeding your gut in the right way, improving the health of your gut microbiome, can have an impact on the serotonin that is made in the brain, but it happens through the mechanism of tryptophan, let's say?

Dr. Emily Leeming 18:53 So I think that's the most logical, what we know from the research so far.

Dr. Rangan Chatterjee 18:57 Okay.

Dr. Emily Leeming 18:57 I think we've ... Again, this is obviously early science, but I think that is really the direction that we're seeing this relationship going in. And, and I think this really gives us this kind of actionable viewpoint where, okay, can I change my gut microbiome? Um, can I help to supply, you know, these extra amino acids, um, to the brain so that that can then potentially have an influence on the mood? And again, you know, this is very much in the viewpoint that this is an extra tool on the toolkit. This is not to replace conventional approaches to kind of mood management. Um, but I think really can be something that we can, you know, be very excited to explore, I think, in the next five years. You know, really looking at, you know, probiotic strategies, for example, for stress, for mood. Um, how can we make things really easy for people to make changes to their diet so that they can feel happier, um, you know, sharper mood, mentality. That's what we're all looking for in life.

Dr. Rangan Chatterjee 19:58 If we go back 25 years, right, and we're saying that back then, this field of gut microbiome research was very, very early, barely starting, right? Back then, I guess we probably still knew that certain things are important, right, for our wellbeing. You know, a good minimally processed food diet is important. Moving your body regularly is important. Trying to get a decent amount of sleep, whatever that is for you, is probably quite important. Making sure you're not chronically getting stressed, I don't think we were as stressed as a society back then, is important. Just to play devil's advocate for a moment, although gut microbiome research has been phenomenal, I've been fascinated by it for years. I've written about it as well, like you, right? So it's, it's incredibly interesting. In terms of practical take homes, and I know you've got your own practical take homes, which we're gonna talk about, could we almost make the case in some ways that it's just reminding us or giving us even more evidence that what we kind of knew 25, 30 years ago holds true, and it holds true for many reasons, including 'cause those things have a positive impact on the gut microbiome?

Dr. Emily Leeming 21:31 Absolutely. I think it's such a good affirmation of the, it's the real foundational things that are impactful for our health, and I think one of the things that, um, you know, I love to say about the gut microbiome, I'm like, "If you can't do it for yourself, do it for your gut microbes." You know, think about it like it's this Tamagotchi that you need to look after. You know, use that as a, as a way that, okay, I do need to do this because I need to look after my gut microbes, and, you know, I'm then gonna feel better as a consequence. Um, and I think in, as Brits, we're kind of weirdly bad about looking after ourselves and very good at looking after other people.

Dr. Rangan Chatterjee 22:05 Mm-hmm.

Dr. Emily Leeming 22:05 Um, and perhaps we can kind of bring that into play, um, for ourselves too.

Dr. Rangan Chatterjee 22:11 I agree. I think Brits are probably not fantastic at that. In my experience as a doctor, I would say I've seen a lot of women in that category, probably more than men, and that's biased by, you know, the patients I've seen, so that's not a, an unbiased random sample. It's people who I saw coming into my practice, right? But I very much saw a lot of women who would put everyone else's needs before their own. You've got

Dr. Rangan Chatterjee 22:41 an interesting section in your book about the difference between female microbiomes and male microbiomes, so perhaps now's a good time to talk about that. What is the difference? And also, within female microbiomes, I'm assuming it can also change throughout the menstrual cycle.

Dr. Emily Leeming 22:58 Yeah. So what we ... So we see that children when they're ... You know, b- before they hit puberty, their microbiomes tend to be quite similar, and really we're then seeing this relationship at puberty, particularly with girls, um, but there's a strong relationship with estrogen, the female sex hormone, um, and the gut microbiome. So it seems to be a two-way relationship in the terms that your gut microbiome is helping to support your estrogen levels, um, but also y- estrogen levels also seem to be influencing your gut microbiome. Um, with boys, we don't see this change so much in, at puberty, although there still is this relationship with testosterone. You know, I get asked, does this mean that one's better than the other? W- we don't know that for sure. It just means that your gut microbiome is just kind of being more in tune to perhaps your different nutritional needs at that point, um, and your different kind of hormonal needs, and it's just kind of working, um, in tune with you. With women, we then see that, um, you know, you get into adulthood, and, you know, you've got then a slightly different r- microbiome to men, and we see this in diseases. What's quite interesting is that we'll see relationships between different types of microbes for men than we do for women. Um, so I think really just highlighting how complex the gut microbiome is and just we need to be kind of careful about how we're talking about it.

Dr. Rangan Chatterjee 24:21 Yeah.

Dr. Emily Leeming 24:21 There's still so much that we need to uncover, and, you know, still we don't necessarily know what, you know, quote-unquote, a healthy gut microbiome even looks like because it's so individual. Um, and then we get into later life, where for both men and women, you know, that diversity of gut microbes starts to go down, and that just means that if there is, uh, you know, infection, that your gut microbiome is perhaps less resilient to being able to kind of ward that off.

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Dr. Emily Leeming 25:20 With women, what's interesting when they go through menopause is that we see this shift, um, from their microbiome going more s- going back to being more similar to a men's microbiome.

Dr. Rangan Chatterjee 25:30 Really?

Dr. Emily Leeming 25:31 Yeah. And we think, again, this is probably because of this relationship with estrogen. What's fascinating about this relationship with estrogen, um, again, this is very kind of early insight, but it'll be amazing to see if we get more research in menopause, which we drastically need. Um, but that, uh, it seems that your gut microbes are, um... certain gut microbes are helping to support your estrogen levels, um, because they're able to recycle some parts of-

Dr. Rangan Chatterjee 25:59 Mm-hmm

Dr. Emily Leeming 25:59 ... waste estrogen. That estrogen is then taken back up into the body and could be made, uh, you know, back into kind of new fully fledged estrogen again.

Dr. Rangan Chatterjee 26:09 Wow. It's fascinating, isn't it?

Dr. Emily Leeming 26:10 I mean, there's so much more that we need to be kind of banging the drum for, for menopause. I'm thrilled that, that more menopause research is coming out and we're, um... You know, it's, it's 50% of the population, you know, we should know more about this. And, and how can we help women who are looking to resolve some of their menopausal symptoms? And again, the taboos and the kind of judgment, uh, that are put around, you know, all these things. I think we've gotta think outside diet, outside lifestyle, really think about the environment we live in also influencing our health, and I mean that, you know, as kind of, um, cultural norms and how we're made to feel about ourselves. You know, all those things are having impact on our stress levels, which is impacting everything.

Dr. Rangan Chatterjee 26:51 Well, and as you talk about in your book, even those things and those, uh, messages and the way we interpret those messages could well be impacting our gut microbiome.

Dr. Emily Leeming 27:03 Yeah, absolutely.

Dr. Rangan Chatterjee 27:04 Which is interesting.

Dr. Emily Leeming 27:05 Yeah. So we see that, um, kind of older adults who are experiencing loneliness tend to have a less diverse gut microbiome. And w- this really m- starts to make sense, where we... You know, if we really recognize that, you know, that everything is covered in microbes. Um, you know, I've got this cup of tea in front of me. There's microbes on this, on the table. You know, these aren't things that we need to be worried about or problematic. These are... Many of them are harmless, kind of friendly, kind of bacteria, um, and other microbes. And so we're constantly introducing to our gut different, new microbes. From one apple, we have 100 million microbes from just eating one apple alone, and we see that then in the gut. So this interaction with human beings is incredibly important. You know, if you kiss someone for 10 seconds, you can transfer 80 million bacteria. So that's-

Dr. Rangan Chatterjee 27:56 A 10-second kiss? Wow.

Dr. Emily Leeming 27:57 10-second kiss. Um-

Dr. Rangan Chatterjee 27:59 What about a 20-second kiss?

Dr. Emily Leeming 28:00 20 sec- I mean, double the whammy.

Dr. Rangan Chatterjee 28:01 [laughs]

Dr. Emily Leeming 28:01 Double whammy. Um-

Dr. Rangan Chatterjee 28:03 I think some people will be quite excited to hear that. Some people may be a little bit freaked out to hear that, I think.

Dr. Emily Leeming 28:09 So what was interesting is that the, uh... some of the researchers who were looking at this said, is this, you know, could this be a new kind of dating technique? Because some of them, the, uh, metabolites that are produced by those bacteria could be then signaling back to us, depending on how enjoyable we find that kiss, um, that this is a kind of compatible mate or not. Um, but again, it's... You know, if we think about the gut being the entirety of our digestive system, so the gut isn't just your stomach, the gut starts in your mouth and goes all the way down to the bottom. The microbes that you're introducing in your mouth are then quite often passing down through to your gut if they survive-

Dr. Rangan Chatterjee 28:48 Yeah

Dr. Emily Leeming 28:48 ... the, uh, you know, acid pit of your stomach.

Dr. Rangan Chatterjee 28:51 I, I love that because if we think about this in a much more broader philosophical level, the gut is in so many ways the interface between our external world and our internal world, right? It's obviously where the immune system, well, most of the immune system, is there, uh, in and around our guts. And so what you're saying about, you know, an apple or touching a table or loneliness or, I don't know, a, a 10-second kiss, right? Or you, you're dating.

Dr. Emily Leeming 29:28 Yeah.

Dr. Rangan Chatterjee 29:28 You kiss this person you're dating for the first time. Although it could sound quite wacky when you first hear it, the more you think about it, the more you go, "Well, wait a minute, it kind of makes sense," right?

Dr. Emily Leeming 29:38 Yeah.

Dr. Rangan Chatterjee 29:38 If you're gonna have this new partner in your life, and given how important mating is to evolution, it's not that surprising that there could be a link. Your gut microbiome, your guts could be doing some form of sensing here and going, "Compatible, not compatible." Do you know what I mean?

Dr. Emily Leeming 29:57 Yeah. I think it kind of makes, uh, kind of intuitive sense in a way, but I think again, we've, we've got so much more to know in terms of the science. But this is what I, you know, I think is so fascinating about this area. There's all these little kind of golden nuggets that are signaling that perhaps make complete sense to us, and we just need to then, um, you know, have a few more years to just really double down and explore this. But, you know, of course, like, you know, the fact we go back to our microbes making up, you know, 50% of our cells, you know, they are heavily influencing, you know, pretty much every aspect of our body. So, you know, it makes sense.

Dr. Rangan Chatterjee 30:30 They're not there by accident.

Dr. Emily Leeming 30:30 They're not there by accident.

Dr. Rangan Chatterjee 30:31 Right? So, you know-

Dr. Emily Leeming 30:31 Yeah, they're playing a role.

Dr. Rangan Chatterjee 30:32 Yeah. Let's think about the things that we can do then to positively influence our microbiome with the knowledge that we don't yet know perfectly what a healthy microbiome is. There has been this, um, maxim, this kind of truth that we- Have thought for many years that a diverse microbiome is a healthy microbiome. Now let's just examine that for a minute. Where has that come from? Do we know that to be true, or are we still speculating?

Dr. Emily Leeming 31:10 So it's, it's true in many ways, but it's also too simplistic, and I think many, many or most researchers in microbiome space kind of recognize this, that it's effectively the best measure that we have so far, but there are also problems with it. So it makes complete sense that we need to have a variety of different microbes. You know, again, like this kind of ecosystem, we need lots of microbes doing lots of different jobs. Um, that also means that there's a resilience there because there's a community of lots of different types of microbes. Um, so if a challenger comes in, um, you know, you've got lots of different microbes that are gonna be able to kind of fight it, fight it off. The thing is, it is too... It is recognized as just being one metric, and also it might not be true of all situations that it's necessarily a healthy gut microbiome.

Dr. Rangan Chatterjee 31:56 Mm.

Dr. Emily Leeming 31:57 I think a key example here is that we know in babies, for example, that a lower microbial diversity is actually more healthy than a high microbiome diversity.

Dr. Rangan Chatterjee 32:06 Wow.

Dr. Emily Leeming 32:06 So there are different stages, you know, where we're thinking actually this, this, this is... You know, there's a bit more to it. The other things that we really want to be thinking about, and actually there was a, a new paper out on this, um, you know, a few months ago of scientists grouping together and making a kind of consensus that we need to-- how can we understand and talk about a microbiome in a way that's, um, really signaling many of the other different aspects that kind of make a healthy gut microbiome? Um, so really thinking about not just really who's there. It's not really-- doesn't really matter necessarily what microbes you have, but it... what matters is what are they doing? What metabolites are they producing? These molecules, you know, are then having an influence on your health, and it doesn't matter perhaps that, you know, one microbe is called Ben and the other one's called Jill, as long as they're doing, you know, a role that is helping to support your health. That resilience piece is again, really important, having a resilient microbiome.

Dr. Rangan Chatterjee 33:05 What does that mean, a resilient microbiome?

Dr. Emily Leeming 33:07 So if a challenger comes in, um, so an infection or a kind of, you know, so that could be from a, a harmful bacteria. Um, perhaps you've got a stomach bug from being on holiday, and you've come back, and you're kind of feeling pretty rough. Um, your microbiome helps to kind of fight off that challenger that's coming in, and that is a resilient microbiome. It's able to return back to its kind of normal, healthy self, um, kind of rapidly and quickly.

Dr. Rangan Chatterjee 33:32 And that sounds like a pretty reasonable thing to conclude, doesn't it? That that sort of principle stands true for many aspects of health. We wanna be able to respond. We wanna be able to deal with the stressor, an infection, and then pretty soon after, get back to where we were before. So it's really interesting 'cause I, I... many-- for many years, I've also been talking about a diverse microbiome being important. And then over the last few years, I almost like to challenge myself in terms of my beliefs and where have they come from, and then I was trying to think, well, we say that a diverse microbiome is a healthy microbiome, but do we know that for certain? You know, I know there's some studies where they've looked at, I think, um, is it the Hadza tribe and they've-- in, in Tanzania, a modern hunter-gatherer tribe, and compared them to an urban Italian population. I'm pretty sure that was it from a few years ago. And what it showed that we've maybe lost, uh, fifty percent, up to fifty percent of our diversity. I don't know if you remember the book Missing Microbes from Marty Blazer. Was it ten years ago, I don't know if you came across it. That was one of the first big books on the microbiome I read when he was sort of making the case that could this increasing rate of chronic disease and autoimmune illness, could it all be linked with these missing microbes and our lower microbial diversity? But one thing I wanted to put to you, Emily, and it, it's really how my view on this has evolved, and, you know, you're a very well-respected microbiome researcher, so I'd love your view on this. It's like you said before, does that diverse microbiome be healthy hold true for everyone? Because there is a very common maxim now put out there that we should be aiming for thirty different plant foods a week. Where has this come from, and why do you think it's been perhaps a little bit over egged? If that's a fair way of putting it.

Dr. Emily Leeming 35:34 Yeah, absolutely. I think that's, that's it in a nutshell. Um, so it comes from a study that came out in twenty eighteen that was, uh, it was called the American Gut Project, and it was, um, really a landmark study of its time. It used... It got ten thousand people to send in their kind of poo samples. Um, and within that, they then did a number of questionnaires. Um, and then they looked at lots of different things within this paper that they kind of produced. Um, so one small aspect of this was looking at the relationship with the number of different plants that were eaten. One of my bugbears with this is that, you know, unlike many other nutritional research that happens, um, you know, it wasn't, uh, a really rigorously collected dietary data. It was effectively one simple survey question, um, of people guesstimating how many plants they ate in a week. And then we come to the number thirty. Um, you know, why thirty? Why thirty plants, you know, being associated with, you know, a higher microbial diversity?

Dr. Rangan Chatterjee 36:36 It, it, it divides by three.

Dr. Emily Leeming 36:38 [laughs]

Dr. Rangan Chatterjee 36:39 Divides into ten, you know?

Dr. Emily Leeming 36:40 Yeah. They, they effectively, you know, they, they were like, "Okay, here's how many plants everyone's gonna be eating. Let's split this into three groups." 'Cause what we do in research, we like to have nice, you know, three buckets that we kind of put people into. Um, and so they... top bucket was people who ate thirty plants or more, and the bottom bucket of people who weren't doing particularly well, um, were ten plants or less. The average obviously were people in the middle, um, take those out. And so they compared the thirty plants, the best people, to the people who were doing worse. Now that usually in science, if you're comparing people who are doing badly to the people who are doing well, you can have any number. It could be twenty-five, it could be forty, it could be fifteen.

Dr. Rangan Chatterjee 37:21 Mm.

Dr. Emily Leeming 37:22 Um, and then within that, the way that the data was collected- It could actually be that perhaps are they just eating more plants in general, and therefore are having a healthier diet, and could that relationship actually be from that? Um, I do think, you know, as a general advice, we do want to be having a variety of different plants in our diet because they're gonna provide all those different nutrients, and polyphenols-

Dr. Rangan Chatterjee 37:44 Mm

Dr. Emily Leeming 37:44 ... and beneficial things for our health. But I really struggle with this, um, you know, equating it to being the same as, you know, the, the eat five a day message, um, which is based on, you know, thousands of different papers that have been kind of reviewed by panels of experts to one single association, um, within, you know, a larger study.

Dr. Rangan Chatterjee 38:04 So you're basically saying, look, your view is that more plant foods and diversity in your diet is generally a good thing, but you're saying that we don't necessarily need to aim for 30. Is that what you're saying?

Dr. Emily Leeming 38:19 Yeah, and I think not getting hung up on... You know, I've definitely come across so many people who, you know, they have packed their fridge with so many different types of fruits and vegetables. They're incredibly stressed because they're noting down every single item that they've eaten, you know, every meal, and then they think they can't eat a tomato on Wednesday because they had it on Monday, and then, you know, it's rotting in the back of their fridge. And I think really that's so counterintuitive and counterproductive to what it really is about, which is just really, again, as we said, those really foundational principles of can we get more fruits and vegetables in? You know, yes, think about diversity and variety, but in a way that's, like, really simple and practical. Like, perhaps it's picking up a bag of mixed, uh, fruits of the forest from the frozen berry section rather than just getting the strawberries or the raspberries. Um, perhaps it's getting, uh, those kind of ready packs of stir-fried veggies, because you've got kind of maybe 10 different plants in there, versus, you know, just picking out cabbage for your stir-fry.

Dr. Rangan Chatterjee 39:18 What about someone who says, "Well, Emily, I hear what you're saying, but I find the 30 plant foods a week quite helpful because it gives me a target, and it helps, uh, inspire stroke, encourage me to keep looking at different ways that I can keep adding these things in." What would you say to that person?

Dr. Emily Leeming 39:35 I say, and as I say in my book, I say, if that's you, that's great, but as long as it's in the way that you find healthy and easy, and it's, and approachable, and you recognize that it's not the be all and end all.

Dr. Rangan Chatterjee 39:47 And it's not the be all and end all for everyone.

Dr. Emily Leeming 39:48 It's not the be all and end all for everyone. And I think, you know, it's finding something that works for you. And I think more often than not, I find that it's the other way where people-

Dr. Rangan Chatterjee 39:56 Yeah

Dr. Emily Leeming 39:56 ... are then incredibly stressed about it, think it's literally, you know, the, the only way you can get good gut health, um, and it becomes just this, its own beast, and it's just not-

Dr. Rangan Chatterjee 40:06 Yeah

Dr. Emily Leeming 40:06 ... yeah.

Dr. Rangan Chatterjee 40:06 I really appreciate that. So my experience with this has, has been, and one of the reasons why I am evolving my view on this, is based upon what I've seen with patients. I'll give you an example, and, you know, in my new book that's just come out, th- I put this case study in chapter one, right? So this lady had heard that advice online that I need 30 different plant foods a week to have a good, healthy gut microbiome, right? And so I, I hadn't seen her at this point. She was this very health-conscious, middle-aged lady, right? And so she was trying her best. She was reading all the blogs, listening to the podcasts. She was going to the shops, trying to do it. She didn't feel good, right? Every time she increased it, she was getting bloating. She was getting constipated. She didn't feel good in herself. Her sleep was being affected. Her energy was being affected. Now, of course, there's many possible reasons for all of those things. And then she thought, this is before she came to see me, she thought, "Ah, maybe I'm doing it too quickly. Let me start really, really slowly." Again, really building it slowly didn't help her either. Now, she wasn't seeing a doctor or a dietician like yourself. She was trying to do this all herself because she was interested. She just wanted to, you know, have more energy and, you know, have more vitality in her life and look after her long-term health. I'm sure many people listening right now are in that boat. She came to see me and said, "Dr. Chatterjee, listen, I'm trying. I'm trying to do this. I've tried all the different ways. I feel like I'm failing." So she felt like a failure. This is, this is why I think sometimes we've outsourced too much of our intuition to external experts, because we never think the advice was the problem. We think that we're the failure. So she thought she was the failure, and I remember what I said to her. I said, "Hey, listen," and I appreciate your perspective on this once I've explained it, because you, you may or may not see it the way I do. But the way I saw it was, I said to her, "Listen, no piece of health advice, no matter how good, in my experience, always applies for every single person. If you're interested, why don't you let me help you figure out what might be the best approach for you at this moment in your life?" And over a few weeks of her playing around with a few things that I suggested, she discovered that for her, a more lower carb style of eating, nothing aggressive, but a, a more lower carb style of eating with five to 10 different plant foods in a week, was feeling really good, okay? So when she was eating like that, she had energy, she had focus, she was sleeping well. She didn't have any bloating. She was opening a- her bowels. She was having a poo, sorry, effortlessly-

Dr. Emily Leeming 42:53 [laughs]

Dr. Rangan Chatterjee 42:53 ... right? Every day. And then I did her blood tests. They were really good. Her HBA1c, the average blood sugar measure, was looking really good. Her inflammation levels were looking really good. Her lipids were looking really good. At that moment in her life, it was very hard for me to make the case that you should be going up to 30 plant foods. I'm not saying that couldn't happen in five years' time, or maybe she needs to repair her gut microbiome, and maybe she can tolerate more in the future. But- One of the problems for me with advice like this that we think is generalized, that we think applies to everyone, is that if you try and do that advice and you can't, you feel like there's a problem with you, which maybe it just ain't the right advice for you. What, what's your take on that?

Dr. Emily Leeming 43:45 So I think you're totally right, that I think we've outsourced from our intuition far too much, and I think that then becomes problematic. And then when I talk about your intuition, it's really listening to how does your body feel, but also things like your hunger and your fullness levels. You know, your body, it has a lot of wisdom, and really being able to tap into that, um, is really just a key pathway to understand, um, what is right for you. There are definitely kind of guiding principles, I think, for most people in terms of, yes, we want to be eating kind of more fruits and vegetables and more whole grains, um, when it comes to our gut microbiome, you know, really thinking about foods that are kind of high in fiber. But very much starting from a place that is right for you and really thinking about where you're at in the here and now, and then thinking, okay, what are the things that I can incorporate that are making me feel great? And I think a lot of the time with these advice, it becomes too black and white, that you either have to kind of-

Dr. Rangan Chatterjee 44:44 Mm

Dr. Emily Leeming 44:44 ... hit that 30 plants, and if you don't, then you're a failure. And I think we have that a lot with many other different pieces of advice as well.

Dr. Rangan Chatterjee 44:51 100%.

Dr. Emily Leeming 44:51 Whereas actually, the most impactful thing you could be doing is just making a small, regular change that you can keep up, that you think tastes great, that you enjoy. That's equally important. Um, and that is incredibly practical. And maybe some days, you know, that change isn't so easy, and that's okay. And then, you know, next week you can get back on and think, okay, well, I'm gonna actually add this in, and maybe I'll add something else in as well-

Dr. Rangan Chatterjee 45:17 Yeah

Dr. Emily Leeming 45:17 ... because I'm kind of in that right frame of mind.

Dr. Rangan Chatterjee 45:19 Yeah. No, I love that. I'm, you know, a huge fan of small changes done consistently. Start where you're at. See what is the right approach for you at this moment in time. It may change in the future. But I just wanna talk about what you just said there. Uh, you mentioned whole grains, okay? So there's a lot of, uh, evidence on the benefits of whole grains and what it can do for our gut microbiome and many other aspects of our health. I guess where my view is evolving, 'cause I'm always looking at what's working, what's not working, right? What has worked with patients, what hasn't worked with patients. And so over the course of my career, Emily, I have seen people thrive on a variety of different diets. Yes, there are some common principles. Most minimally processed as much as possible, whole food as close to natural form, you know, trying to not have excess added sugar. Um, all those things for sure, like broad framework principles. But within that, I've seen all kinds of different things. So I've seen some patients thrive on a whole food plant-based diet, but I've also seen patients thrive, depending on their state of health, on a low carb diet. And so therefore, I, I look back and go, okay, Rangan, what's going on here? Well, maybe there is no one perfect human diet that works for every single person. Maybe there are some principles to follow, but we have to personalize those principles for any individual. So if we think about the gut microbiome, and we say that a diverse microbiome, and we get a lot of that diversity from plant foods, um, is good for our health and our wellbeing, I think we also need to be able to explain when there are outliers to that, where that's seemingly not the case, right? So I've seen some patients who are not having loads and loads of fiber, and they are thriving. I acknowledge that there's great evidence on fiber, right? So I'm not saying there isn't. I'm just like, yeah, but there are some patients I know... Honestly, I've been doing this for a long time, I'm like, I cannot make a case that you are not thriving. Like, there's one lady I know who is really, really low carb. She doesn't have many vegetables and fruits at all, and I don't know anyone with more focus and energy and cognition, and she's sleeping well, and her A1C is amazing, and her lipids are amazing. So, so for me, I'm always thinking with the, with the state of gut microbiome research, what do we know, but also what do we not know yet? So I guess what I'm trying to share with you is I agree with you that fiber is very, very beneficial, but how do you explain why it is that some people are seemingly doing quite well without much fiber in their diets?

Dr. Emily Leeming 48:10 So I'd probably say that, um, you know, fiber comes from many different plant foods. You know, we've got fruits, vegetables, nuts, seeds, beans, legumes, whole grains. Um, you know, s- if you are perhaps feeling better by focusing more on fruits and vegetables, you know, you're still getting a significant amount of fiber from that. I think what's really interesting is that, um, perhaps a lot of the problems that people are having, um, when it comes to, uh, fiber actually might be more related to what's called FODMAPs-

Dr. Rangan Chatterjee 48:39 Yeah

Dr. Emily Leeming 48:39 ... from Mon- Monash University, um, really kind of identifying that these, um, fermentable sugars can cause people to feel a bit uncomfortable. And I think for many people they then think, oh, I need to cut that out. But actually it's about working through that systematically, um, finding which foods kind of help you to feel okay, um, can you have, uh, the ones that may perhaps a bit problematic, but in smaller quantities, and just kind of avoiding stacking them. So that's one group. I would say, you know, there's also kind of other groups where, as you say, that if you're finding a way of eating that works for you, that you feel healthy, your metrics are all healthy, you know, realistically, there's no perfect one diet for everyone-

Dr. Rangan Chatterjee 49:21 Mm-hmm

Dr. Emily Leeming 49:21 ... as you say. It's about finding the diet that you can stick to-

Dr. Rangan Chatterjee 49:24 Yeah

Dr. Emily Leeming 49:24 ... that has those healthy principles, and I think we have so much kind of warring between-

Dr. Rangan Chatterjee 49:29 Yeah

Dr. Emily Leeming 49:29 ... um, all these different diets saying, oh, this one's best, this one's best. I'm like, the one that's best for you is the one that you can stick to. That is what the best one is, and that you feel great on

Dr. Rangan Chatterjee 49:38 Like, no one generally is gonna follow something in the long term if they're not feeling good on it. But, you know, no one likes to feel full and really bloated. And so, do you know what I mean? I mean-

Dr. Emily Leeming 49:49 Yeah

Dr. Rangan Chatterjee 49:49 ... yes, they might have to work through some things, but in the long term, no one's gonna do that 'cause it doesn't feel good.

Dr. Emily Leeming 49:54 Though I would say, and I do feel like I talk in defense of some bloating, um-

Dr. Rangan Chatterjee 49:58 Okay

Dr. Emily Leeming 49:58 ... 'cause I think we've become, uh, like, almost, like, too afraid of any bloating whatsoever and thinking that any bloating is a problem. Um, we're actually having a small amount of bloating in that hour after a meal is actually a sign of actually a very happy gut microbiome because what happens when your gut microbes feed on the foods they love, so particularly fiber, but also they feed on things like called polyphenols, which are kind of, um, colors that are found in pigments that are found in fruits and vegetables, um, and they feed on kind of other things as well. They make those molecules for your health, but as a side effect, they make gas. So you're effectively kind of throwing them a bit of a kind of, you know, digestive party-

Dr. Rangan Chatterjee 50:40 Yeah

Dr. Emily Leeming 50:40 ... and, you know, they're letting off a few fireworks, but that's actually a good thing, right?

Dr. Rangan Chatterjee 50:45 Yeah.

Dr. Emily Leeming 50:46 When bloating becomes problematic, it's when bloating is staying, um, high throughout-

Dr. Rangan Chatterjee 50:51 Yeah

Dr. Emily Leeming 50:51 ... the day. It feels incredibly uncomfortable. It's not going down. Um, that's where it's like, okay, can we step back and think, is there perhaps a food intolerance, or is there something else going on? Um, and how can you kind of ease that? Or perhaps it's stress related. It might not even be food related.

Dr. Rangan Chatterjee 51:08 Yeah

Dr. Emily Leeming 51:08 Um, many other things.

Dr. Rangan Chatterjee 51:08 It's so often stress related.

Dr. Emily Leeming 51:10 Yeah.

Dr. Rangan Chatterjee 51:10 It really is.

Dr. Emily Leeming 51:11 Yeah.

Dr. Rangan Chatterjee 51:11 I love that. I think your next book should be called In Defense of Bloating.

Dr. Emily Leeming 51:14 [laughs]

Dr. Rangan Chatterjee 51:15 I think it's something that... You're right, you know, n- it's, it's almost become something that no one wants to ever experience, and I think what you said makes a lot of sense. And if I just sort of weave that in with other themes that we speak about on this podcast quite regularly, there's been quite a lot of guests recently in the movement world, like Helen Hall or Lawrence VanLingen, who have been talking about the importance of not holding your belly in because of what it does to your breathing patterns. You can lead to dysfunctional breathing patterns. But, you know, when you breathe in, your belly should actually go out. But because of the societal conditioning, people are not doing that anymore. People are holding their bellies in, right? It's because, you know, we don't want our belly to go out. That's causing issues with breathing, which can cause issues with anxiety, and you're kind of painting a similar picture through the lens of gut health, which is a bit of bloating after eating is actually pretty normal.

Dr. Emily Leeming 52:12 Absolutely, and I think, you know, as you say, we're conditioned to think that we must have a flat stomach, and that, you know, our-

Dr. Rangan Chatterjee 52:18 At all times

Dr. Emily Leeming 52:18 ... at all times, and that our, you know, our bellies cannot move at all. Um, and then as you say, if we're wearing tight restrictive clothing, we know that if you kind of have, uh, bloating, then that can be, you know, make bloating much worse or kind of potentially cause bloating for some people 'cause it's just restricting-

Dr. Rangan Chatterjee 52:33 Mm-hmm

Dr. Emily Leeming 52:33 ... your digestion. Um, and, you know, really actually, again, that movement piece-

Dr. Rangan Chatterjee 52:38 Yeah

Dr. Emily Leeming 52:38 ... if you're feeling that you are bl- bloa- bloated, what about going for a walk afterwards? You know, let it, let it all out outside, which is, you know, really healthy and, and great for you as well.

Dr. Rangan Chatterjee 52:48 So celebrate the bloat.

Dr. Emily Leeming 52:49 [laughs]

Dr. Rangan Chatterjee 52:50 I love it.

Dr. Emily Leeming 52:51 Celebrate a little bit of the bloat, make peace with it, and, uh, yeah, if you need to go for a walk afterwards, just, you know-

Dr. Rangan Chatterjee 52:56 Okay

Dr. Emily Leeming 52:56 ... ease off.

Dr. Rangan Chatterjee 52:57 Let's get some of your practical advice. You've got some really cool mnemonics, uh, that I've read about in your book. I've seen you talk about in some of your videos. If someone wants to say, "Hey, Emily, listen, okay, I, I get it. You know, the gut microbiome's important for many aspects of my health. What can I do to improve my own gut microbiome?" With the acknowledgement that we're all unique and we have to personalize things for us, if you could maybe walk us through some of your mnemonics to help us, uh, take away a bit of practical advice, that would be useful, I think.

Dr. Emily Leeming 53:30 Absolutely. So I think the real key piece, um, as you say, uh, depending on what works best for you, but fiber is something that we're drastically missing in the UK diet. So we're missing about 40% of that recommended 30 grams of fiber that we need a day. And I find this fascinating because, you know, we're so obsessed with talking about protein, protein, you know, shakes, bars, it's everywhere, high protein, and actually most of us are getting enough protein as it is. But we're actually, um, missing out on the fiber. It's this forgotten nutrient that we need to be paying attention to. Now, what happens with fiber and your gut microbiome is that fiber feeds your gut microbiome specifically to specific types of fiber called prebiotic fibers. Now, these are fibers that are found in beans, um, they're found in onions, garlic, leeks, asparagus, um, lots of different other foods, and when your gut microbes feed on this fiber, they're able to make those short chain fatty acids which have an anti-inflammatory effect and able to signal to your brain, and lots of other healthy molecules as well which support the health of your gut barrier lining and also are able to then travel into your bloodstream and going across your body to your different organs. So fiber is something that I really feel quite strongly that it's had this, um, kind of boring reputation of just something that just kind of helps you go to the loo, helps you do a poo. Um, it is so much more than that. Um-

Dr. Rangan Chatterjee 55:01 So it needs new PR basically.

Dr. Emily Leeming 55:02 It needs new PR, absolutely. Um, you know, it helps with your heart health. It helps to soak up bad cholesterol for that to be removed from your body as waste. Um, it helps to balance your blood sugar levels, giving you longer lasting energy. So it's not only just helping with your gut microbiome, it's having many other benefits in your body too.

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Dr. Emily Leeming 55:53 And when I talk about fiber, the key foods that I really want to talk about are what I call the BGBGs, so B-G-B-G-S. That's beans, greens, berries, grains, and nuts and seeds. And in particular, what might surprise people is actually the highest fiber foods are whole grains, nuts and seeds, and beans, much more so than most fruits and vegetables, which I think is quite counterintuitive for some people. They think, oh, well, actually, you know, lettuce, you know, I need to be eating salad for days. Actually, lettuce contains about 1.8 grams of fiber per 100 grams. In comparison, chickpeas has about five times, uh, six times more than that.

Dr. Rangan Chatterjee 56:37 Mm-hmm.

Dr. Emily Leeming 56:37 Um, something like the nuts and seeds, for example, let's compare that to flax seeds or chia seeds. That's about 25 to 30 grams of fiber per 100 grams, so really, really big jump. And what I really want to highlight with that is that it shouldn't feel stressful to add more fiber into your diet. It's about making these BGBGs, um, you know, an everyday, uh, or most day foods, I really say. It doesn't have to be every day. Um, but kind of adding into your essential shopping list, and that just gives you kind of an easy kind of fiber boost on a daily basis to feed your gut microbes and look after the health of your gut, because a healthy gut also supports a gut microbiome.

Dr. Rangan Chatterjee 57:16 Yeah, I, I love that. And just to circle back to something I said before, I think it's really, really relevant here. Fiber comes in a variety of different places, right? So I was telling you about someone I know very well, a good friend of mine, who is absolutely thriving on a very, very low-carb diet. Sure, if you saw her as a patient, you'd be like, "Why would you change anything when you're functioning like this and your blood tests look like that," right? Now, I'm now thinking through to her diet from what I know, and although it's very low carb, she does have a lot of nuts, okay? She does have, uh, quite a bit of, uh, black coffee. She does have tomatoes often, uh, with some herbs, right? She has olive oil. Um, a few times a week she'll have some sweet potatoes, right? So what I'm saying is that we have a perception of what high-fiber foods are. Just from what I've said to you there, without knowing this lady's history and everything about her, although on the face of it, it's quite a low-carb diet, and it is, I, I guess there's probably not as much fiber there as you might want someone to have, but there is some fiber there, and there are some plant foods that will be helping her microbiome. Is that... Is that fair to say?

Dr. Emily Leeming 58:50 I think, I think it sounds like she probably is having more fiber than we think, because I think we, we associate fiber-

Dr. Rangan Chatterjee 58:56 Exactly

Dr. Emily Leeming 58:56 ... with being just, like, you know, boring brown bread. We're able to list off high-protein foods, you know, off the get-go. I'd say I can ask anybody, you know, tell me three high-protein foods. They know, they could say, you know, uh, meat, fish, eggs straightaway.

Dr. Rangan Chatterjee 59:10 Yeah.

Dr. Emily Leeming 59:10 When I say the same for fiber, you know, people draw a blank, and I really think we need to change that, and really recognize that, you know, fiber is found in lots of different other, you know, so many different plants, you know, fruits, vegetables, beans, legumes, nuts, seeds, whole grains.

Dr. Rangan Chatterjee 59:25 Why don't you, you share with us your five favorite high-fiber foods?

Dr. Emily Leeming 59:30 So I, I wanna share the surprising ones, actually-

Dr. Rangan Chatterjee 59:32 Okay, sure

Dr. Emily Leeming 59:32 ... because I think that's always quite fun. Um, so avocado, I think we associate with being kind of this gorgeous, rich kind of, you know, really good of healthy fats. Um, one avocado contains about eight grams of fiber.

Dr. Rangan Chatterjee 59:44 Okay.

Dr. Emily Leeming 59:45 That's pretty amazing.

Dr. Rangan Chatterjee 59:45 My friend who I was talking about, she has an avocado every morning.

Dr. Emily Leeming 59:47 There we go. There we go.

Dr. Rangan Chatterjee 59:48 Do you know what I mean?

Dr. Emily Leeming 59:48 Yeah.

Dr. Rangan Chatterjee 59:48 So that's low carb, but it's high fiber.

Dr. Emily Leeming 59:51 Yeah.

Dr. Rangan Chatterjee 59:52 Right?

Dr. Emily Leeming 59:52 And then dark chocolate, uh, is a great one. That's about 11 grams of fiber per 100 grams. So I usually go for something, you know, ideally 70 above, in a, in an ideal optimal world, kind of 65%. Um, I am a huge fan of rye pumpernickel bread, which, you know, is affordable. You can get it from the supermarket. Um, and effectively, it's that really flat, uh, bread that contains a lot of, kind of has a lot of, um, seeds in it quite often as well. And I really like that because one slice of that is seven grams of fiber. So you know already that if you're having that for breakfast with some eggs, with your avocado, that you're hitting probably about 10 grams, a third of the-

Dr. Rangan Chatterjee 1:00:32 At breakfast?

Dr. Emily Leeming 1:00:33 At breakfast already, a third of your fiber. So those three foods are kind of surprising. I do think some really great ones to have, um, are nuts and seeds. Again, I just want to kind of highlight the kind of chia seeds, flax seeds, um, you know, even something like a kind of dried coconut, um, flakes, um, are again really high in fiber. What I like to do is have a, a jar of them by the kettle, and that means that I can see it. It's gonna prompt me. If I'm making a cup of tea, I can have them as a snack. Um, but also, they're really great to sprinkle onto your breakfast in the morning or perhaps toast them, put them into a salad, uh, or on top of your veggies.

Dr. Rangan Chatterjee 1:01:09 You, you, you talk in your book about breakfast being a gut health opportunity.

Dr. Emily Leeming 1:01:14 Absolutely.

Dr. Rangan Chatterjee 1:01:15 But that's interesting, isn't it? Where, you know, instead of thinking of breakfast as something we're doing to just get us going for the day or to break our overnight fast, you're... I guess it's giving it that sort of PR makeover, saying, no, no, this is a gut health meal if you do it the right way.

Dr. Emily Leeming 1:01:29 We see people who skip breakfast tend to have less fiber and have a lower intake of many kind of micronutrients. Um, again, of course, this is very individual. You know, I've got some people who are able to just have, uh, you know, a really kind of nutritious, fiber-rich diet and that's the rest. But I have to say, it does make it a lot harder, because fiber, while it's found in many different foods, we do need to be really making sure that, um, we're getting in, uh, the right amounts to really hit that 30 grams of fiber a day. And if we're c- taking out a meal, that makes it much, much harder.

Dr. Rangan Chatterjee 1:02:05 Mm-hmm. One of the recommendations you make in your book is to have, or to aim for half of your plate being vegetables

Dr. Emily Leeming 1:02:16 So it could be, I said vegetables mainly, but it also could be fruit, for example, if it's breakfast. Um, and I think for me, it's really about, um, really about mental load when it comes to health advice and what we're doing. You know, do we want to be spending a lot of time overthinking or weighing or measuring something? That is not, you know, that's stressful. We don't have time for that. So for me, it's about those simple, practical approaches that you can literally just look at your plate and say, "Okay, half of that is vegetables, half of that is fruit," um, for example, whichever way you're going, or perhaps you're having a bowl of fruit at the end of the meal. Um, that's just such a simple thing that every one of us can do without thinking about it, that means that we're getting more of that fiber in. And then, of course, those fruits and vegetables also contain all those other nutrients that we need for our health as well.

Dr. Rangan Chatterjee 1:03:05 Do you make a distinction between starchy vegetables and non-starchy vegetables, or does that depend on your patients?

Dr. Emily Leeming 1:03:13 So I'd say I didn't necessarily include potatoes in that definition, um, because-

Dr. Rangan Chatterjee 1:03:20 Because, you know, they're, they're starchy vegetables

Dr. Emily Leeming 1:03:22 ... they're starchy vegetables. Um, and I think, you know, potatoes are actually, you know, really satiating, and-

Dr. Rangan Chatterjee 1:03:28 Sure

Dr. Emily Leeming 1:03:29 ... you know, there's lots, especially in the skin, lots of nutrients. Um, but I think we do tend to think of them in the kind of everyday person as a carb rather than as a vegetable. So for me, it's about anything that we consider as a, as a kind of carb in our day-to-day, let's just, you know, put that on, you know, maybe a quarter of your plate and, you know, really have those, those greens and those different colors.

Dr. Rangan Chatterjee 1:03:53 Yeah. I, I would say for many years, I've tried to have half of my plate be non-starchy veg. You know, I think it's, I don't always manage it, but it's just a nice way of... And I, and I've used that recommendation with patients for years, and it's, it's really quite helpful, particularly, I would say, in a world where many people are now carrying excess weight and have insulin resistance and are pre-diabetic or even type 2 diabetic. Again, there are many ways to tackle that, of course, uh, and you can have starchy vegetables on a diet and still tackle those things. But I found for many people, it's really helpful to really focus on a lot of those non-starchy vegetables to fill up your plates. You know, you get full. There's a lot of fiber in it. You tend to eat less of the other stuff because it's so filling. I guess you're saying that you find that quite useful, like not including potatoes in those recommendations. Would you include sweet potatoes in that?

Dr. Emily Leeming 1:04:47 Oh, I think sweet potato gets bounced back and forth. I think sweet potato can realistically probably go in either, because it's got that dark orange color. You know that you're getting-

Dr. Rangan Chatterjee 1:04:55 Yeah

Dr. Emily Leeming 1:04:55 ... kind of extra polyphenols from that, which are also good for your microbiome and important for your health. Um-

Dr. Rangan Chatterjee 1:05:00 Okay, so fiber's one of these big things that you want to encourage people to think about.

Dr. Emily Leeming 1:05:05 Yeah, absolutely. And I think, uh, you know, there's other compounds that we can also think about when it comes to our health and for the health of our gut microbiome too, particularly talking about compounds called polyphenols. So polyphenols are these kind of compounds that give fruits and vegetables a lot of their pigment and color. So that could be, for example, the, the deep purple of an aubergine, um, and then kind of comparing that to kind of another fruit and vegetable of a different color. Um, and what these different groups of polyphenols tend to do different things for our health, so this is why we want this rainbow of foods. We want this variety of different colors for our health. What happens with our gut microbes, that they feed on these polyphenols in a similar way to fiber-

Dr. Rangan Chatterjee 1:05:48 Mm-hmm

Dr. Emily Leeming 1:05:48 ... so that helps to also support the health of our gut microbiome. In the UK, most of our polyphenols come from coffee and tea. Um, so coffee and tea are, you know, great sources in themselves, but, you know, in comparison to herbs and spices, they're pretty low on the list. Um, other surprising foods that are really rich in polyphenols and incredibly affordable are things like beans, particularly black beans. And I like to say this because I think, um, quite often when we think about, um, kind of polyphenol-rich foods, you know, somebody might say, "Oh, I need to go and buy some wild blueberries," which cost, you know, an absolute fortune. But actually, things like black beans contain about eight times more polyphenols than wild blueberries, and, you know, you're then getting something that is affordable, that's doing great for your health. And yes, you can still have those blueberries, but you don't feel like you have to go and spend, you know, three times as much to be doing it.

Dr. Rangan Chatterjee 1:06:45 Yeah, and I think that's one of the plus sides of thinking about a lot of these foods that we think are supporting a healthy microbiome, like the prebiotic fiber foods you were mentioning before, you know, onions, garlic. Um, I don't know if you mentioned Jerusalem artichokes or not.

Dr. Emily Leeming 1:07:03 Me. Jerusalem artichokes. Exactly

Dr. Rangan Chatterjee 1:07:03 You know, 'cause that's in the top five list that was published a couple of years ago. You know, uh, these are relatively cheap foods. As, you know, I appreciate everyone's got different income levels and different levels of access, but they're not the most expensive foods, which I think is, is quite encouraging. If people are trying to make small changes to have an impact on their health, it's like, well, you could start there, and you're gonna start to see a difference.

Dr. Emily Leeming 1:07:29 Absolutely, and I think we've, you know, overcomplicated, um, gut health far too much. You know, it's, it, it's been made out to seem that we need to have this supplement or kind of that latest new thing that's come out, and actually it's those core key principles that are doing the best things for your gut, and that is just, you know, maybe it's adding in some onions and garlic to, you know, if you're making a, a stew or a soup. Um, perhaps it's sprinkling on some extra herbs or some nuts and seeds, um, next time, you know-

Dr. Rangan Chatterjee 1:07:58 Yeah

Dr. Emily Leeming 1:07:58 ... you have your lunch. Like, really simple, practical things. Those are the things that are actually making the biggest impact for your health.

Dr. Rangan Chatterjee 1:08:05 Do you know, one thing I think a lot about when I think about gut's health, I think about all this modern science and the new measurement techniques we now have to look at gut health. And yes, all this advice now on how we can improve our gut's health and things we're talking about, fermented foods, kefir, kimchi, you know, of different levels of expense depending on how much you wanna spend, how much you can spend, right? And then obviously, uh, supplements and all that kind of stuff. And I think this is sometimes a little controversial for people, uh, and I'd really under- I'd love to know your take on this. Are we having to focus on gut health in the 21st century so much because the default has become so unhealthy? Right, so let's back up 50 years, right? Where we didn't have the same level of access to ultra-processed foods. We didn't have as much chronic stress as we're now seeing in, you know, many countries, where people were more active and less sedentary than they are today, right? People were sleeping more than they are now. We know all of, of those four things, the four pillars, as I call them, impact our gut microbiome. In a world back then, right? And I know we're not in that world, but as a thought experiment, if you are mostly eating an unprocessed, uh, non-ultra-processed diet, which I know most people are not, but if you were, and if you were sleeping well and had low levels of manageable stress and were m- you know, maybe walking for an hour a day, I wonder if you would have to focus on gut health as much, or whether your default state would actually be pretty good gut health.

Dr. Emily Leeming 1:10:02 I think if you're already doing those foundations for gut health automatically, then, then inherently, you know, you're having a better health status and your gut microbiome is happier. Then we tend to focus on the things that could potentially go wrong, I think, as we're, we're drawn to potential issues. And I think we recognize that the food environment that we're in, um, you know, we're have an onslaught of marketing from different companies. Even walking through a supermarket, you know, the particularly, you know, the way that the supermarket is structured is, you know, what's called nudging. Um, they purposely place the eggs at the very end so that you walk through the crisp aisle, for example. You know, there's very kind of strategic placement of kind of food and food products to make you buy because it's a business. But that inherently means that those things can end up in our shopping bags, and therefore, on our tables. And I think, you know, it's, it's very difficult because how much autonomy do we have? Yes, we have some autonomy, but there is so much that is-

Dr. Rangan Chatterjee 1:11:02 Mm

Dr. Emily Leeming 1:11:02 ... actually subconscious that is happening and driving these food choices.

Dr. Rangan Chatterjee 1:11:06 Yeah, and a lot of people, of course, uh, do acknowledge this, are, you know, really struggling, right? They, they are under chronic stress. They are sleep deprived. They're having to work more than perhaps they want to, to keep the lights on at home, to keep the heating on, right? That, that is very real for many people. It was more ... It's not to deny that. I know that's real, and I know we need help with our gut's health. It's just this broader philosophical point, like, I suspect, like, a lot of the so-called blue zones, right, these, uh, populations around the world where they're seemingly living to, you know, a ripe old age and really good rates of health, they are having really good gut health, or they had really good gut health, but they weren't thinking about their gut health. They ... I don't think they were-

Dr. Emily Leeming 1:11:55 Yeah

Dr. Rangan Chatterjee 1:11:55 ... actively thinking of, oh, you know, I better increase my fiber. I better increase my polyphenols. I better do this. Actually, they were living a life that naturally was resulting in good quality gut health. That's, that's kind of the point I was trying to get at.

Dr. Emily Leeming 1:12:09 Yeah, I think, I think we want to be in that state of health where we don't have to think about health, right? And I think that's perhaps, you know, just carrying on from your point now where, um, you know, these communities are, you know ... I mean, these communities are communities. You know, they are interacting with each other. They're spending a lot of time outside. They're doing exercise. You know, that is just things they're doing for pleasure and for joy that make them feel good, that's very intuitive-

Dr. Rangan Chatterjee 1:12:35 Mm

Dr. Emily Leeming 1:12:35 ... that perhaps we stepped away from, and are now doing those things because we think we should. And actually, we need to get back in touch-

Dr. Rangan Chatterjee 1:12:43 Yeah

Dr. Emily Leeming 1:12:43 ... with those things being what make us feel good, and that we enjoy them, and very much that being, you know, a key purpose that we should do it for pleasure, too.

Dr. Rangan Chatterjee 1:12:53 Yeah. What's your take on time-restricted eating and early dinners?

Dr. Emily Leeming 1:12:58 So again, you know, early science coming out around this. Um, I think we see mostly from the evidence that we do have that having a kind of eating window, so that's, you know, from the time that you first eat something in the morning to you last eat something at night, being a period of about 10 to 12 hours. And that just means that that is associated with a more diverse microbiome, um, but also better mood, better energy, um, and also better cognition as well. And I think really when we think about that, we think about the fact that if you're eating really late, so we know that if you eat, you know, within the hour before you go to sleep, that can impact your sleep, and then that impacts on how you feel the next day. There's also been a, a kind of small, tightly controlled study where they looked at people who ate at 6:00 PM versus 10:00 PM, and the people who ate at 10:00 PM had higher levels of cortisol, which is the stress hormone. So really just thinking about why might this be? Likely it's because our body runs on its body clock, uh, as does our digestion-

Dr. Rangan Chatterjee 1:13:58 Mm

Dr. Emily Leeming 1:13:58 ... is in tune with our body clock, and we respond to light and, and night and day. During the daytime, our body knows that it's awake, that that is the time that when we're gonna be eating. And at nighttime, our digestion is still happening, but it's just slowing down. It's getting ... Your body is relaxing, ready to go to sleep. So really trying to focus, um, you know, that, that eating window on, yes, trying to maybe perhaps have your breakfast, and then perhaps eat dinner a little bit earlier. But I think I really kind of share this with people that find what works well for you-

Dr. Rangan Chatterjee 1:14:32 Yeah

Dr. Emily Leeming 1:14:32 ... within your life and lifestyle patterns, and none of this advice is ever a rule. It's, it's what is appropriate for you, that fits in your lifestyle, that makes you feel good, and I very much talk about things as being kind of most days rather than every single day.

Dr. Rangan Chatterjee 1:14:47 Mm-hmm.

Dr. Emily Leeming 1:14:48 And an example for that might be, um, you know, I've been invited to go out for dinner, you know, on a Friday night, and I'm gonna go out with my friends and have a nice dinner at an Italian restaurant. I'm not gonna say, "Oh, I can't come because I'm meant to be, you know, honoring my time-restricted eating." Like, that's an unhealthy choice to say that you're not gonna go and spend time with friends and family.

Dr. Rangan Chatterjee 1:15:06 Yeah. Interesting. I think time-restricted eating is one of the most powerful interventions I've seen in my years as a clinician. It really is. Uh, I think it's a simple thing that for most people is doable. Like, you mentioned an eating window of 10 to 12 hours. Let's even make it super simple, call it 12 hours, right? Where from the moment you take your l- first bite in the morning to your last bite is 12 hours. So, you know, that could be 8:00 AM till 8:00 PM or, yeah, I probably do 10, 11 hours, I think, you know. It's p- I try and do, you know, breakfast at 8:00 AM, finish eating dinner by 6:00 PM. I have children. I like to eat early with the children. It's what works for me and the concepts of my life. But I have seen it, even when there was early science in only, uh, mouse studies, maybe in ... When did Satchin Panda first start publishing this? Maybe 2014?

Dr. Emily Leeming 1:16:04 Yeah.

Dr. Rangan Chatterjee 1:16:04 2015?

Dr. Emily Leeming 1:16:04 Yeah.

Dr. Rangan Chatterjee 1:16:05 Something like that. I thought, "This kind of makes sense with what I know about circadian biology. I can't see any real downside here. Why don't I try it with certain patients and see if it helps?" I would see all kinds of improvement. Sleep would get better. IBS, irritable bowel syndrome, wow, so many people improve their IBS symptoms when they go to some form of time-restricted eating, in my experience. So I think it's a ... I think it can be really helpful. Um, I appreciate you sharing the science of what it can do for the gut microbiome. I think a lot of the benefits may also be mediated through better sleep.

Dr. Emily Leeming 1:16:42 Yeah, absolutely. We know sleep is so, so important, and also that sleep then impacts, you know, your eating behaviors for the next day. Because if you're tired, you're then more drawn to-

Dr. Rangan Chatterjee 1:16:51 Yeah

Dr. Emily Leeming 1:16:51 ... things that are perhaps less healthy for us, and then it becomes this kind of self-fulfilling cycle.

Dr. Rangan Chatterjee 1:16:56 I think anyone who's ever had a sleep tracker, and, you know, the pros and cons of sleep trackers are maybe beyond the scope of this conversation, but I think one of the things they can teach people is the effect of eating close to your bedtime and what it does to the quality of your sleep. You know, f- few years ago when I got my very first sleep tracker, that was probably one of the key learnings for me, along- alongside what alcohol can do, uh, to, you know, your deep sleep, was like, oh, wow, if I'm eating within an hour of bedtime, or even for me within two hours of bedtime, you can see it in your sleep quality and feel it the next day. So although it can be challenging sometimes, I know I'm my best version of myself when I can stop eating three hours before bed. Now, I know for some people that can be really challenging, especially 'cause of modern life, right? Because, you know, that evening meal is often when we down tools and we, you know, connect with our family and our partner and whatever it might be, right? So that's ... That often can be by the time someone's commuted home or, you know, it's often late in the evening, or later than you might want. So I guess we have to be mindful of that and that ... and, and understand that not everyone can do it. But generally speaking, I think an earlier dinner time tends to be better. Would you agree with that?

Dr. Emily Leeming 1:18:21 Yeah. I, I definitely am, uh, in that, yeah, that, that club of, um, thinking it's better to, to eat earlier for dinner. But of course, as you say, within what works for you. But I think for the people who are thinking about trying this and seeing whether it works well, you know, even something like bulk prepping at the weekends if you've got time, you know, s- getting some meals that are already, already happening. That could be something like I'm just gonna roast a pan of roast vegetables, and then you've got that ready to go, then you can add that to some whole grain couscous, and maybe some fish. That'll maybe take 15 minutes to cook. But also things like really recognizing the power of leftovers. I'm a huge fan-

Dr. Rangan Chatterjee 1:18:58 Mm-hmm

Dr. Emily Leeming 1:18:58 ... of leftovers-

Dr. Rangan Chatterjee 1:18:59 Yeah, me too

Dr. Emily Leeming 1:18:59 ... and repurposing that. So it could be that maybe you've made a, a really nice, um, kind of warm salad for the day before. Um, you've made it with kale and with nuts and seeds, and you've got maybe some chicken and some feta in there, and some avocado. You know, could you have that as a side for your meal f- at dinner time, perhaps the next day? Or if it's some other something else, can you add some chickpeas to it and make it into a more kind of substantial, hearty meal? Um, lots of different things you can do, but I really think that leftovers get kind of forgotten as, like, a health tool that we can, uh, really tap into.

Dr. Rangan Chatterjee 1:19:35 Mm-hmm. What's the relationship between alcohol consumption and our gut microbiome?

Dr. Emily Leeming 1:19:41 So alcohol, uh, is unfortunately, um, for us, you know, wanting to enjoy a kind of an occasional tipple, is not really that great for our gut and our gut microbiome, um, and also for our brain as well. We're seeing even a small amount of alcohol isn't necessarily, um, very good for us. What's happening with alcohol in the gut is it starts to kind of irritate the gut lining, and I think anyone can relate to this. Um, perhaps, you know, in your youth when you had maybe a few too many drinks, you know, you then need to kind of dash to the loo, and you've got kind of a change in your kind of ... in, in your poo, basically. Um, so that is not necessarily something that your gut microbes like. What I do say is that we've got to be realistic, that I'm not gonna say everyone needs to swear off alcohol. If you are gonna choose an alcohol- Um, for your gut microbes, likely red wine is the best option. That's because we think it's so rich in polyphenols, more than kind of many other alcohol types, 'cause of that deep purple-red color, um, giving that color to the, from the polyphenols to the red wine. What we see from some research is that, uh, red wine in small amounts, so about one glass a day maximum, um, is associated or linked to a more diverse, um, kind of healthy microbiome. Um-

Dr. Rangan Chatterjee 1:20:59 Than what? Than someone who's-

Dr. Emily Leeming 1:21:01 Than-

Dr. Rangan Chatterjee 1:21:01 ... not drinking

Dr. Emily Leeming 1:21:02 ... than if someone is having, uh, kind of other alcohol types.

Dr. Rangan Chatterjee 1:21:06 Okay, so you're comparing within alcohols.

Dr. Emily Leeming 1:21:07 Within alcohols.

Dr. Rangan Chatterjee 1:21:08 Got it. Because I guess what you're not saying is if you don't drink, at the... Let's say someone doesn't drink alcohol at the moment for whatever reason, I don't think you're saying it would be good for you to start drinking red wine for your gut microbiome.

Dr. Emily Leeming 1:21:22 No. No.

Dr. Rangan Chatterjee 1:21:22 Yeah.

Dr. Emily Leeming 1:21:22 Yeah.

Dr. Rangan Chatterjee 1:21:23 Just want to clarify that.

Dr. Emily Leeming 1:21:24 And I think, I think basically if you're looking for a polyphenol source, there are many other sources of polyphenols-

Dr. Rangan Chatterjee 1:21:28 Without-

Dr. Emily Leeming 1:21:28 ... that you can be getting

Dr. Rangan Chatterjee 1:21:29 ... without the downsides.

Dr. Emily Leeming 1:21:30 Without the downsides, but if you are an alcohol drinker, then perhaps, you know, if you are gonna drink alcohol, then choose a red wine if that's a choice that you're gonna make. Um, but ideal world, we would not need to be drinking that much alcohol, 'cause it's not great for us.

Dr. Rangan Chatterjee 1:21:45 I'm really interested in how our gut microbiome, um, changes throughout our lifetime. Uh, in the book, you say that the longer you live with someone, the more similar your gut microbiome can grow to be. That's really interesting, because, you know, as of a few weeks ago, I've been married for 17 years, so a long time, right? And it's amazing how, you know, whilst you remain different people with your own preferences and your personalities, you know, it is amazing how you do kind of take on a few elements of the other person. You know, you spend 17 years together, you know, things are gonna morph together. So it's interesting that how you might start to have similar gut microbiomes. Of course, it makes sense on one level in the sense that you're, you know, depending on how much time you're spending together and what you're doing, with that time you're, you know, you're probably eating similar foods, touching similar surfaces, right? And all that kind of stuff. So that's one aspect I wanted to talk to you about. The other aspect related to how our microbiome changes, and I'm asking you because you're a microbiome researcher. Someone like me, who is born to Indian immigrants, so you know, mom and dad's, when they came to the UK in the 1960s and 1970s, they had never left India before, right? So they would've been eating traditional foods, like my family in India, in Bengal, would've had meats and fish and vegetables and rice and lentils. There's a perception that Indians are vegetarians. It's, it's not true. Many are, many are not as well. [laughs] Uh, so in West Bengal, in Calcutta, you know, people do eat meats and fish, okay? So Mom and Dad would've had, uh, a certain gut microbiome informed by their upbringing and being in India. So they come to the UK, and then me and my brother were born here in the UK, right? And so as a kid, I would eat at home at least, not at school, but at home, the foods that Mom would cook, which would typically be Indian foods. Not exclusively, but typically. And so I guess I'm really fascinated, do you know anything about how, let's say for immigrants or, you know, children of immigrants, do their microbiomes, uh, more take on the microbiomes of the country in which they're settled? So for me, I'm born abroad, so in the UK, lived here my entire life. Or are they more like their parents' microbiomes? You know, is there any research on that at all?

Dr. Emily Leeming 1:24:21 So there was a study done in the US a few years ago, and what they looked at, uh, Thai immigrants coming into the US.

Dr. Rangan Chatterjee 1:24:29 Mm.

Dr. Emily Leeming 1:24:29 And looking at the generations, uh, from that, that were then kind of living in the US. What they saw was that their gut microbiome diversity actually started to decrease, so that was kind of, you know, seen as being a less healthy gut microbiome, and they saw that as being partly 'cause of the shift in the foods that they were eating, becoming more kind of acclimatized to the kind of US diet, which, you know, we've got to caveat is, you know, typically this Western-style diet that isn't necessarily particularly healthy. What was really interesting is that they saw changes in the types of microbes, um, that tend to feed on certain types of fibers. So really seeing this shift from changing from some of the foods that they were kind of traditionally eating, um, the, the gut microbiome kind of shifting and recognizing that, okay, I've got new different fiber sources, um, new different foods that I need to then, you know, be able to, uh, kind of shift and be able to break down and get energy from and digest. Um, so very much, uh, shifting and changing form to work with the new diet that was happening.

Dr. Rangan Chatterjee 1:25:34 Wow. It's fascinating, isn't it? And I'm sure we'll probably see more research on this over the coming years. In terms of the longer we live with someone, the more similar our gut microbiomes can potentially become, what can we, what can we take from that?

Dr. Emily Leeming 1:25:48 It's, it's very much that, you know, our, our microbiome is perhaps outside of us as well. Um, our microbiome is, uh, not just, you know, inside of us. It's we've got a skin microbiome, and then our house microbiome, which is kind of contributed to-

Dr. Rangan Chatterjee 1:26:03 Mm

Dr. Emily Leeming 1:26:03 ... by the members of the family and the people that we live with.

Dr. Rangan Chatterjee 1:26:05 Wow.

Dr. Emily Leeming 1:26:06 So yes, we might be eating the same foods, and that is one part of it that's kind of causing our microbiomes to be more similar, but it's also the fact that, you know, if you were to take a family out of one house and put them in another house, that kind of microbial imprint will, will carry with them, and, you know, that will be their surroundings as well.

Dr. Rangan Chatterjee 1:26:24 Yeah.

Dr. Emily Leeming 1:26:24 So there's constantly shifting and changing, um, and of course, you know, uh, you know, hugging and skin contact is also, uh, as well.

Dr. Rangan Chatterjee 1:26:32 And, and 10-second kisses.

Dr. Emily Leeming 1:26:33 And 10-second kisses.

Dr. Rangan Chatterjee 1:26:34 Kisses, of course. Yeah.

Dr. Emily Leeming 1:26:35 [laughs]

Dr. Rangan Chatterjee 1:26:36 Listen, I've, I've so enjoyed talking to you. I know we've gone into all kinds of different areas. Perhaps to kind of, um, wind this conversation down- I'm guessing people are already sold from this conversation on the importance of their gut's health. If they're still not, give us a top line, why should someone care about the health of their gut?

Dr. Emily Leeming 1:27:01 I think, think about how you feel in the here and now, and that's really, you know, is it your mood, your energy, your cognition? You know, that is what your health is giving you, and I think, you know, we gotta recognize that your gut microbiome is playing a key role in that. Of course, it's one piece of the puzzle, but the beauty of the gut microbiome is that we're able to change it, and therefore, we can improve our health by making changes to support our gut microbiome.

Dr. Rangan Chatterjee 1:27:27 Okay. And you've mentioned a lot of tips throughout this conversation, but if you were just gonna boil it down to something quite short at the end, if someone now saying, "Right, Emily, I'm all in. This is the year I'm gonna sort out my gut's health," what are your top tips? What would you say to them?

Dr. Emily Leeming 1:27:47 So let's recognize that stress, sleep, and movement are really important, but I, because I'm a dietician, I'm gonna give you some foodie ones.

Dr. Rangan Chatterjee 1:27:54 Great.

Dr. Emily Leeming 1:27:55 Um, so we talked about the BGBGs, so beans, greens, berries, grains, and seeds, nuts and seeds. I'm gonna count that as one.

Dr. Rangan Chatterjee 1:28:04 Okay.

Dr. Emily Leeming 1:28:04 Being your high fiber. And then we know that hydration is really important, not just for your gut, but also for your brain. So really thinking about, um, getting enough water in. You can get polyphenol sources from tea, from coffee. Uh, and the way that you can check how hydrated you are is by looking at the color of your pee. It should be a pale lemonade color. Then we've also got fermented foods. Fermented foods, particularly kefir, really interesting new research coming out, small tightly controlled studies showing that there is this connection between the gut and the brain. Um, studies showing that improves your relational memory. This is memory that you need to recognize people's faces and to remember where you left the keys. So trying to include some kind of fermented food, um, in most of your days. And I think that time-restricted eating piece that we talked about earlier, you know, trying not to eat too late and giving your body time to digest before you go to sleep is gonna help with your gut microbes too.

Dr. Rangan Chatterjee 1:29:04 Amazing. Well, Emily, thank you for all the work you're doing. Thank you for spreading the message of gut health all around the world, and thank you for coming on the show. If you enjoyed that conversation, then I think you are really going to enjoy this one.

1:29:18 Who wants to live longer if you're not able to have good brain health? You can live to 150, 200, go for it, but if your brain isn't working, it's not worth living.

1:29:27 Yeah, yeah.

1:29:28 And I think that the good choices, those little tiny little tweaks we make, they can have a big difference