#428: Poop, Peptides & The Power of Microbiome | The Secret Longevity Organ With Dr. Grace Liu
Today, I'm joined by Dr. Grace Liu, often known as the “Gut Goddess,” a trailblazer in the world of microbiome science and founder of The Gut Institute. In this conversation, we take a bold dive into an often-overlooked pillar of longevity: your poop. That's right—Dr. Liu unpacks the fascinating and sometimes surprising science showing how gut health shapes everything from your immune system and brain to your lifespan itself.
Together, we explore why your gut deserves the spotlight as a hallmark of aging, how modern life quietly destroys our microbiome, and what that means for your risk of everything—from brain fog to autoimmune issues and mood disorders. Dr. Liu doesn’t shy away from controversial topics, sharing her insights on fecal transplants, the danger of fad fiber supplements, and her favorite simple-but-powerful foods to feed your beneficial bacteria.
If you’re curious about the most underrated levers for extending your healthspan, how resilience really starts in the gut, and why diversity—not just in your diet but in your microbes—is the ultimate marker of youth, you’ll want to tune in. Get ready for a mix of ancient wisdom, cutting-edge research, and practical strategies to transform your gut and your health.
Learn more from Dr. Grace Liu below:
Website: https://thegutinstitute.com/
What We Discuss:
Introduction to host ... 00:00:00
Dr. Grace Liu on the gut as a hallmark of aging ... 00:04:06
Peptides, FMT, and evidence for gut-driven regeneration ... 00:05:04
FMT safety, immune education, and the environmental “microdosing” effect ... 00:07:07
Links between gut aging, the immune system, and mental health ... 00:08:13
Diet, ancestry, and resistant starch for butyrate production ... 00:15:01
Ancestral diet, microbiome differences, and pitfalls of shortcuts ... 00:18:53
Fiber, polyphenols, and the key longevity bacteria ... 00:24:09
Gut markers, loss of diversity, and ABC species signature ... 00:25:15
Risks of overhyped probiotics, strep, and broad interventions ... 00:36:29
Peptides, bioregulators, and repairing the gut ... 01:12:01
Practical longevity: movement, daily habits & where to learn more ... 01:22:46
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Some episodes of the Longevity With Nathalie Niddam podcast are supported by partners whose products or services may be discussed during the show. The host may receive compensation or earn a minor commission if you purchase through affiliate links at no extra cost to you. All opinions shared are those of the host and guests, based on personal experience and research, and do not necessarily represent the views of any sponsor. Sponsorships do not imply medical endorsement or approval by any healthcare provider featured on this podcast.