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.