The Gut Health Podcast

Fiber isn’t one-size-fits-all and for some people, more isn’t better. In this episode, we explore why most people under-eat fiber, why certain fibers can worsen symptoms, and how to personalize intake in a way your body can actually tolerate. Dr. Heather Armstrong shares emerging insights on fiber function, microbiome capacity, and practical strategies for going low and slow. We also unpack new science explaining why fiber supports gut health in some individuals, while triggering issues in others with reduced fermentative activity. 
In this episode, we discuss:
• The fiber gap, health risks, and minimum intake targets
• How solubility, viscosity, and fermentability guide fiber choice
• Matching fiber types to IBS, diarrhea, and constipation
• Why whole foods matter more than isolates
• Citrus peel pectin and simple kitchen hacks
• Why “low and slow” dosing reduces gas and pain
• How long microbiome changes and symptom relief actually take
• When fiber supplements help (and when they don’t)
• Individualized fiber needs in IBD (and implications for IBS, MS, and liver disease)
• Why dietitians are essential for precision nutrition
This episode is especially relevant if you’ve been told to “just eat more fiber”—and it didn’t go well.
Learn more about Dr. Heather Armstrong's novel research:
Gut feeling: new test and precision diet could boost health for people with IBD. U of A research team in clinical trials for their innovative AI-powered tool that could reduce inflammation by “rewiring” the gut microbiome.
References:
Ramezani F, Pourghazi F, Eslami M, et al. Dietary fiber intake and all-cause and cause-specific mortality: An updated systematic review and meta-analysis of prospective cohort studies. Clin Nutr. 2024
Chang SC, Cassidy A, Willett WC, Rimm EB, O'Reilly EJ, Okereke OI. Dietary flavonoid intake and risk of incident depression in midlife and older women. Am J Clin Nutr. 2016 
Armstrong HK, Bording-Jorgensen M, Santer DM, et al. Unfermented β-fructan Fibers Fuel Inflammation in Select Inflammatory Bowel Disease Patients. Gastroenterology. 2023
Armstrong H, Mander I, Zhang Z, Armstrong D, Wine E. Not All Fibers Are Born Equal; Variable Response to Dietary Fiber Subtypes in IBD. Front Pediatr. 2021
Gao J, Lee AA, Abtahi S, et al. Low Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols Diet Improves Colonic Barrier Function and Mast Cell Activation in Patients With Diarrhea-Predominant Irritable Bowel Syndrome: A Mechanistic Trial. Gastroenterology. 
This episode is sponsored by Activia.
Learn more about Kate and Dr. Riehl:

Website: www.katescarlata.com and www.drriehl.com
Instagram: @katescarlata @drriehl and @theguthealthpodcast

Order Kate and Dr. Riehl's book, Mind Your Gut: The Science-Based, Whole-body Guide to Living Well with IBS.

The information included in this podcast is not a substitute for professional medical advice, examination, diagnosis or treatment. Always seek the advice of your physician or other qualified health care provider before starting any new treatment or making changes to existing treatment.

Glucagon-like peptide-1 (GLP-1) can transform metabolic health, but only with smart dosing, adequate dietary protein, regular strength training, and mental health support. 
In this episode, we explore how GLP-1 medications work in the brain and gut, why metabolic health is more than BMI or a weight on the scale, and how to use these drugs safely. Our expert guest, gastroenterologist, Dr Supriya Rao shares practical dosing, side effect strategies, and what makes results stick.

• Defining metabolic health beyond BMI and weight
• How GLP-1s reduce appetite and slow gastric emptying
• Healthy weight loss pace and preserving lean muscle
• Practical + science-backed dosing and individualized titration
• The unknown risks of compounding and microdosing
• Managing nausea, reflux, and constipation
• Diet shifts: smaller meals, more fiber, adequate protein
• Mental health, body image, and stigma in care
• Durability of results and maintenance dosing
• New indications: MASH (metabolic dysfunction-associated steatohepatitis), sleep apnea, cardiovascular protection
• Building an educated care team

References/Resources:
Tzang CC, Wu PH, Luo CA, Chen ZT, Lee YT, Huang ES, Kang YF, Lin WC, Tzang BS, Hsu TC. Metabolic rebound after GLP-1 receptor agonist discontinuation: a systematic review and meta-analysis. EClinicalMedicine. 2025 Nov 28;90:103680. 
Ghusn W, Hurtado MD. Glucagon-like Receptor-1 agonists for obesity: Weight loss outcomes, tolerability, side effects, and risks. Obes Pillars. 2024;12:100127. Published 2024 Aug 31. 
Moiz A, Filion KB, Tsoukas MA, Yu OHY, Peters TM, Eisenberg MJ. The expanding role of GLP-1 receptor agonists: a narrative review of current evidence and future directions. EClinicalMedicine. 2025 Jul 17;86:103363. 
Integrated Gastroenterology Consultants (Dr. Supriya Rao's practice site)
Book: The GLP-1 Kitchen: A Cookbook for Living Well on Weight Loss Medications Escobar S-N et al. (contains affiliate marketing link)
Learn more about Kate and Dr. Riehl:

Website: www.katescarlata.com and www.drriehl.com
Instagram: @katescarlata @drriehl and @theguthealthpodcast

Order Kate and Dr. Riehl's book, Mind Your Gut: The Science-Based, Whole-body Guide to Living Well with IBS.

The information included in this podcast is not a substitute for professional medical advice, examination, diagnosis or treatment. Always seek the advice of your physician or other qualified health care provider before starting any new treatment or making changes to existing treatment.

This year on The Gut Health Podcast, we dug deeper than ever into the science that shapes our bodies, the myths that confuse us, and the everyday habits that actually move the needle. We challenged probiotic controversies, rethought alcohol culture, explored resilience from gravity to mindset, and turned stress management into practical, usable skills. We broached the topic of vagus nerve stimulation and the potential role of psychedelics and the gut-brain connection!
The theme in 2025 was connection: the conversation between food and microbes, the way those microbes steer our mood and gut motility, the posture-driven shifts in biology, and the everyday choices that ignite changes across the whole body.
It’s not just gut health—it’s a map of how we think, feel, move, and live. And we’re just getting started.
Key topics in this episode include:

• the evolving research with gut science and why personalization matters
• facts vs fads on probiotics, ferments, and “leaky gut syndrome”
• lifestyle foundations that beat quick fixes
• alcohol reduction strategies and social swaps
• food–mood links, excess fructose, and serotonin
• stress prescriptions such as adding diaphragmatic breathing into your daily routine
• how to build gravity resilience 
• what's happening in the psilocybin research landscape and safety considerations
• practical habit stacking for hydration, movement, and sleep
• communicating with providers when evidence conflicts to help you navigate your personal gut health needs.

Looking to boost overall wellbeing with meditation, breathing exercises or better sleep? Calm has you covered with 40% off a premium subscription. Visit http://calm.com/guthealthpod. 

Learn more about Kate and Dr. Riehl:

Website: www.katescarlata.com and www.drriehl.com
Instagram: @katescarlata @drriehl and @theguthealthpodcast

Order Kate and Dr. Riehl's book, Mind Your Gut: The Science-Based, Whole-body Guide to Living Well with IBS.

The information included in this podcast is not a substitute for professional medical advice, examination, diagnosis or treatment. Always seek the advice of your physician or other qualified health care provider before starting any new treatment or making changes to existing treatment.

A growing number of patients with stubborn IBS symptoms are asking: if the gut and brain are wired together, could changing one transform the other? In this episode, we sit down with Dr. Emeran Mayer and Dr. Erin Mauney to explore what the emerging field of psychedelic-assisted therapy could mean for gut-brain health, beyond the headlines and hype. 
In this episode we cover:
Why traditional IBS treatments often fall short.
How psilocybin opens a neuroplastic “window” for processing pain, stress, and interoception.
The therapeutic process: preparation, guided dosing, and integration.
Early study results: symptom relief, reduced visceral sensitivity, and improved self-illness separation.
Safety, variability, and practical questions about access and candidacy.
If you’re curious about neuroplasticity, the brain-gut axis, psilocybin, and the future of IBS care, this episode offers a grounded, hopeful, and responsible guide to what’s known, and what’s next. 
This episode is sponsored by GI Psychology. 
Disclaimer: Participation in the research study mentioned in this podcast is entirely voluntary and independent of The Gut Health Podcast. Please review all study details before deciding to take part. The Gut Health Podcast does not endorse or verify the research, its sponsors or its findings. Direct any questions to the study organizers using their official contact information.
References: 
Psychedelic-assisted therapy: An overview for the internist
Barnett BS, Mauney EE, King F 4th. Psychedelic-assisted therapy: An overview for the internist. Cleve Clin J Med. 2025;92(3):171-180. Published 2025 Mar 3. doi:10.3949/ccjm.92a.24032
Psychedelic-assisted Therapy as a Promising Treatment for Irritable Bowel Syndrome
Mauney, Erin MD*; King, Franklin IV MD†; Burton-Murray, Helen PhD‡; Kuo, Braden MD‡. Psychedelic-assisted Therapy as a Promising Treatment for Irritable Bowel Syndrome. Journal of Clinical Gastroenterology 59(5):p 385-392, May/June 2025. | DOI: 10.1097/MCG.0000000000002149 
Psilocybin and IBS treatment: First psychedelic study in gastroenterology
Learn more about the MGH study with Dr. Erin Mauney and colleagues here.
Learn more about Kate and Dr. Riehl:

Website: www.katescarlata.com and www.drriehl.com
Instagram: @katescarlata @drriehl and @theguthealthpodcast

Order Kate and Dr. Riehl's book, Mind Your Gut: The Science-Based, Whole-body Guide to Living Well with IBS.

The information included in this podcast is not a substitute for professional medical advice, examination, diagnosis or treatment. Always seek the advice of your physician or other qualified health care provider before starting any new treatment or making changes to existing treatment.

Dr. Brennan Spiegel, author of Pull: How Gravity Shapes Your Body, Steadies the Mind, and Guides Our Health, reveals how gravity shapes everything from our digestive health to our emotional wellbeing in this fascinating exploration of "biogravitational medicine." He presents the revolutionary concept that conditions like IBS and depression may be tied to how well our body resists gravity.
• Gravity resilience refers to how well your body manages Earth's gravitational force
• People with hypermobility conditions like Ehlers-Danlos syndrome often experience gut issues when their internal suspension systems are compromised
•  The gut hangs from a suspension system like ‘ornaments on a Christmas tree,’ and if it weakens, the intestines can sag, leading to digestive issues
• Our language around emotions reflects our relationship with gravity – we feel "down" when sad and "up" when happy
• Most serotonin (90–95%) is made in the gut with help from our microbiome, where it helps regulate muscles and systems that manage our body’s relationship with gravity
• Strategies to strengthen gravity resilience
• Hypopressive exercises that draw the belly upward can improve internal organ support
• The STACK TEN diet focuses on tryptophan-rich foods to support serotonin production
• Mental and physical resilience share similar concepts - the ability to "bend without breaking"

Check out Dr. Spiegel's new book "Pull" releasing October 7th, which explores how gravity affects human health and how building gravity resilience can help us find balance, stand stronger, and live longer.

References and Resources:
The Gravity Doctors Podcast Link
Brennan Spiegel MD’s book, Pull (This is an affiliate link. We may earn a small commission at no extra cost to you and only recommend products we trust.)
Effect of diet on serotonergic neurotransmission in depression. Neurochem Int. 2013;62(3):324-329.
Tryptophan-rich diet is negatively associated with depression and positively linked to social cognition. Nutr Res. 2021;85:14-20.
J. Wurtman: Brain serotonin, carbohydrate-craving, obesity and depression. Obes Res. 1995;3 Suppl 4:477S-480S.
Research on sleep & tryptophan Sleep and Diet: Mounting Evidence of a Cyclical Relationship. Annu Rev Nutr. 2021 Oct 11;41:309-332.
Amy Cuddy's paper on "The Power Pose" highlights how adopting confident postures can boost mood, increase self-assurance, and positively influence how others perceive you!
Learn more about Kate and Dr. Riehl:

Website: www.katescarlata.com and www.drriehl.com
Instagram: @katescarlata @drriehl and @theguthealthpodcast

Order Kate and Dr. Riehl's book, Mind Your Gut: The Science-Based, Whole-body Guide to Living Well with IBS.

The information included in this podcast is not a substitute for professional medical advice, examination, diagnosis or treatment. Always seek the advice of your physician or other qualified health care provider before starting any new treatment or making changes to existing treatment.