Peter Attia MD283 ‒ Gut health & the microbiome: improving and maintaining the microbiome, probiotics, & more
At a glance
WHAT IT’S REALLY ABOUT
Colleen Cutcliffe on Microbiome Science, Akkermansia, and Rigorous Probiotic Development
- Cutcliffe explains that the microbiome is a highly mutable, fast-evolving ecosystem shaped mainly by diet and antibiotics, and that strain-level and function-level differences between people make it hard to study.
- Fecal microbiota transplants cure C. diff infections at about 99% versus roughly 70% for antibiotics, which she says shows a microbiome intervention can change physiology but is a messy, non-reproducible drug.
- Most commercial probiotics rely on easy-to-grow Lactobacillus and Bifidobacterium strains and on CFU counts, which she argues are a weak metric compared with flow cytometry that distinguishes live, dead and in-between cells.
- Akkermansia, a strict anaerobe that is depleted in obesity and type 2 diabetes, is described as stimulating GLP-1 release through a surface protein, the secreted protein P9, and propionate that other strains convert to butyrate.
- Pendulum's five-strain formulation lowered A1C by 0.6 versus placebo in a 76-person, 90-day trial, and the company is now funding about a dozen third-party studies while selling through a consumer model.
IDEAS WORTH REMEMBERING
5 ideasThe microbiome is mutable, which makes it a promising therapeutic target.
Cutcliffe says diet, travel, antibiotics and stress can change it quickly, unlike human genetics, and this is what drew her to the field.
Calling bacteria good or bad oversimplifies things.
She argues context and ecosystem determine a microbe's effect, noting that most people carry C. diff without harm until antibiotics remove its competition.
Fiber is the key food for the gut and the production of butyrate.
Gut microbes ferment fibers we cannot digest into short-chain fatty acids such as butyrate, which fuels colon cells and triggers GLP-1 release; she says typical intake is far below the 20 to 30 grams recommended.
CFU counts say little about what is in a probiotic.
Cutcliffe says most cells in many probiotics are dead, CFU only counts those able to form colonies, and labels may not reflect the count at the end of shelf life.
Akkermansia may influence metabolic health through several GLP-1 pathways.
She describes AMUC1100, P9 and propionate-derived butyrate all stimulating L cells, and says the effect would be a physiologic, meal-linked rise rather than the strong GLP-1 exposure from injectable drugs.
WORDS WORTH SAVING
5 quotesThey're optimizing for their environment, and so again, if you, uh, sort of take diet as the primary thing that can modify your microbiome, it's the primary thing that can modify your microbiome 'cause that's their food. They're living in your gut. They're waiting for you to feed them.
— Colleen Cutcliffe
When you take an antibiotic, that's essentially almost like a nuclear bomb to your microbiome. It kills everything in there.
— Colleen Cutcliffe
Some brilliant marketer decided that that was gonna become the metric, the name of the game for probiotics.
— Colleen Cutcliffe
In almost every supplement, every probiotic out there, the majority of what's in that pill is dead probiotic, and you don't see any of that when you use this technology.
— Colleen Cutcliffe
Really in the microbiome, the person matters. And so crossover designs are gonna give you way more information about what's doing what in that person.
— Colleen Cutcliffe
High quality AI-generated summary created from speaker-labeled transcript.
