
Fiber has been talked about for decades — but emerging research suggests most of us still don't understand what it actually does, how much we need, or why the modern diet has left us so dramatically short of it. In this episode of The Mind–Gut Conversation, Dr. Mayer is joined by Dr. Matt Amicucci, food scientist and co-founder of OneBio, to discuss the cutting-edge science of dietary fiber and its far-reaching role in gut health, metabolism, and disease prevention. Dr. Amicucci explains how different fiber structures interact with specific microbial communities in the gut to produce short-chain fatty acids like butyrate — and how those molecules influence everything from blood glucose regulation to GLP-1 secretion to long-term mortality risk. He also shares the story behind Glycopedia, the largest dietary fiber database ever built, and how it is being used to develop a new generation of personalized, microbiome-targeted nutrition. They also discuss why 95% of Americans fall short of even the minimum recommended fiber intake, how decades of food processing have systematically stripped fiber from the diet, and what it will take to close that gap. This is a practical, science-driven discussion for anyone interested in nutrition, the gut microbiome, and the future of food. -------------------------------------- Connect with Dr. Mayer: Website: https://www.emeranmayer.com Instagram: https://www.instagram.com/emeranmayer/ X (Twitter): https://www.twitter.com/emeranmayermd Facebook: https://www.facebook.com/EmeranMayerMD/ LinkedIn: https://www.linkedin.com/in/emeranmayer/ -------------------------------------- Chapters: 0:00 - Introduction 2:38 - Matt's Origin Story: From Chef to Food Scientist 6:43 - Why Fiber Is Having a Moment 8:58 - The Fiber Deficit Crisis 11:36 - What Decades of Low Fiber Intake Has Done to the Microbiome 13:47 - Building Glycopedia: Mapping the World's Fibers 19:33 - Why Whole Foods Alone Aren't Enough 21:42 - Not All Fiber Is Created Equal 25:47 - Introducing GoodVice 27:34 - The Health Case for 10 More Grams a Day 33:49 - Rethinking Sugar and Fiber Together 36:34 - Fiber, Butyrate, and GLP-1 38:42 - The Future of Personalized Fiber Nutrition 40:17 - What's Next for OneBio