The microbiome is back! In 2018, we chatted with Dr. Elaine Hsiao - a UCLA microbiome researcher– and learned all about the hot cauldron of your guts. In this 2025 update bonus, we chat again with Dr. Hsiao to get updates on the last 7 years of her research. We also stop by White Plains, New York to hang out with Dr. Miguel Freitas, lead nutritional microbiologist and director of the non-profit Danone Institute North America, and ask a million questions about good vs bad microbiota, how they simulate a human gut in a lab, what exactly is a pre-biotic vs. probiotic, why are they such good friends, how diet can impact not only your gut health but also your heart and your brain — and if friendly yogurt critters are robust enough to make the journey from your mouth to your toilet.  Browse Dr. Freitas’s publications on ResearchGateVisit the Hsiao Lab at UCLA and follow Dr. Hsiao on Google ScholarDonations went to GiveDirectly.org/ologies and the Los Angeles Regional Food BankMore episode sources and linksOther episodes you may enjoy: Microbiology (GUT BIOME), Molecular Neurobiology (BRAIN CHEMICALS), Fromology (CHEESE), Scatology (POOP), Gustology (TASTE), Cardiology (THE HEART)400+ Ologies episodes sorted by topicSmologies (short, classroom-safe) episodesSponsors of OlogiesTranscripts and bleeped episodesBecome a patron of Ologies for as little as a buck a monthOlogiesMerch.com has hats, shirts, hoodies, totes!Follow Ologies on Instagram and BlueskyFollow Alie Ward on Instagram and TikTokEditing by Mercedes Maitland of Maitland Audio Productions, Jake Chaffee, and Jarrett Sleeper of Mindjam MediaManaging Director: Susan HaleScheduling Producer: Noel DilworthTranscripts by Aveline Malek Website by Kelly R. DwyerTheme song by Nick Thorburn Hosted by Simplecast, an AdsWizz company. See pcm.adswizz.com for information about our collection and use of personal data for advertising.