Tired of hearing “it’s just stress”?  IBS experts Drs. Laurie Keefer and Darren Brenner join Kate Scarlata and Dr. Megan Riehl to set the record straight on irritable bowel syndrome.

IBS is a real, biologically based disorder involving the gut–brain axis, the microbiome, immune function, and nervous system signaling. Understanding how these systems interact reshapes how we diagnose, personalize treatment, and support long-term symptom relief.

If you’ve felt dismissed, confused, or stuck in trial-and-error care, this episode will help you feel validated, informed, and empowered with a clearer, science-backed path forward.

Together we break down:

• The value of a positive diagnosis (not endless testing)
• The impact of trauma and adverse childhood experiences (ACEs) on gut sensitivity 
• Using diet to support symptom relief without unnecessary food restriction
• How to comprehensively match treatment to your triggers

Support & Professional Resources

If you’ve experienced ACEs or trauma and want support from a GI psychologist or trauma-informed provider, these directories can help: 

• GI Psychology (virtual services available)
• Rome Foundation GastroPsych Provider Directory
• Trauma-Informed Mental Health Provider Directory

Partnering with a clinician trained in gut–brain disorders and trauma-informed care can safely address both physical symptoms and nervous system patterns. 

• Aggeletopoulou et al. Unraveling the Pathophysiology of Irritable Bowel Syndrome: Mechanisms and Insights. Int J Mol Sci, 2025.
• Keefer L et al. The Role of Resilience in IBS and Other Chronic GI Conditions. Clin Gastroenterol Hepatol, 2021.
• Chang L et al. Sex, Anxiety, and Resilience in the Association Between Adverse Childhood Experiences and IBS. Clin Gastroenterol Hepatol, 2025.
• Dong et al (UCLA Church Lab). Experiences of discrimination are associated with microbiome and transcriptome alterations in the gut. Front Microbiol, 2024.
• Scarlata K et al. Utilization of Dietitians in the Management of Irritable Bowel Syndrome by Members of the American College of Gastroenterology. Am J Gastroenterol, 2022.
  •  How Kate Does It: Low-FODMAP Diet (AJG)

This episode is sponsored by Ardelyx. 

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.

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.

Dr. Mary Ellen Sanders, an expert in probiotic microbiology, helps us decode the often confusing world of probiotics, prebiotics, and postbiotics by explaining their scientific definitions, evidence-based benefits, and practical applications for gut health (and beyond). 

This episode has been sponsored by Activia.

• Probiotics are live microorganisms that confer health benefits when consumed in adequate amounts
• For something to be called a probiotic, it must be alive, defined to the strain level, and tested in the research setting for health benefits
• When selecting probiotics, look for products with strain designations and doses guaranteed through end of shelf life, not just "at time of manufacture"
• The US Probiotic Guide (usprobioticguide.com) offers independent assessments of probiotic products and their evidence levels, including specific conditions or symptoms
• Specific probiotic benefits include supporting gut function during antibiotic use, reducing respiratory infections, and decreasing crying in colicky babies
• Prebiotics are substrates (often fibers, but also polyphenols) that feed beneficial gut bacteria
• Research suggests about 5 grams of prebiotics daily may be beneficial
• Postbiotics are beneficial preparations of dead microorganisms or their components, challenging the notion that microbes must be alive to benefit health
• When trying probiotics, consult with your health care provider first, as there are some conditions in which they are contraindicated. 
• Multi-strain probiotics and synbiotics are commonly available but rarely tested in their exact formulations

References and resources: 

• Clinical Guide to Probiotic Products Available in USA http://www.usprobioticguide.com
• Research review: Is There Evidence to Support Probiotic Use for Healthy People? https://www.sciencedirect.com/science/article/pii/S2161831324000991?via%3Dihub
• International Scientific Association for Probiotics and Prebiotics www.ISAPPscience.org 
• Perspectives on products combining functional ingredients without testing the product as formulated:
  • Cunningham M, et al.. The influence of product formulation on the activity and clinical outcomes of probiotic and prebiotic products. Trends Food Sci Technol: 112, June 2021, Pages 495-506.
  • Sanders ME, et al. 2014. Effects of genetic, processing, or product formulation changes on efficacy and safety of probiotics. Ann N Y Acad Sci. 1309(1):1-18.
• Probiotic product survey: 
  • Merenstein DJ, Guzzi J, Sanders ME. 2019. More Information Needed on Probiotic Supplement Product Labels. J Gen Intern Med. 34(12):27

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. Mark Pimentel, Executive Director of the MAST program at Cedars-Sinai in Los Angeles, shares groundbreaking insights into the small intestinal microbiome that challenge long-held beliefs about gut bacteria. Findings from his team’s REIMAGINE study reveal that the small intestine is far from sterile, as previously thought—instead, it harbors substantial bacterial communities that play a critical role in health and disease, especially in conditions such as IBS and SIBO.

• E. coli and Klebsiella act as aggressive "Ferrari" bacteria that outcompete other microbes and destroy microbial diversity when overgrown inducing a "apocalyptic" disruption of the small bowel microbiome.
• Lactobacillus, commonly found in many probiotics, may act as a disruptor in the small intestine and new research correlates higher small intestinal levels with obesity and unhealthy aging (more research needed)
• The PLACIDE trial found probiotics didn't reduce C. diff or antibiotic-associated diarrhea but did increase bloating
• Food poisoning is the only proven cause-and-effect trigger for IBS, with stress acting as a modifier rather than initiator
• Combining rifaximin with NAC works 10x better for SIBO by targeting bacteria in both intestinal fluid and mucus
• A new compound (CS06) shows promise for reducing methane production and relieving constipation
• Three distinct gas patterns (hydrogen, methane, hydrogen sulfide) correlate with different symptom patterns and respond to targeted treatments

This episode was sponsored by Salix Pharmaceuticals. 

Resources: 

DDW 2025 Abstracts by the Mast Program and Dr. Pimentel

A Novel Microbiome Therapy, CS-06 (MTD Blocker), Reduces Methane Production in Stool Culture

Real World Study of Three-Gas Breath Testing Nationwide and The Association with Symptoms

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. Iris Wang of the Mayo Clinic shares cutting-edge insights on gut health across the lifespan, including advancements in pharmacogenomics for personalized medication selection and innovative breathing techniques to relieve abdominal distension. She busts common myths about bloating, revealing how diaphragmatic dysfunction rather than excess gas may be the culprit. Dr. Wang also emphasizes the importance of starting gut health education early, helping kids and parents alike understand that pooping shouldn't be painful or forced. 

• How pharmacogenomics helps identify why some patients metabolize medications differently, leading to better medication choices with exploration on the hope and/or hype of precision medicine in the GI world (Wang et al 2019)

• Explanation of abdomino-phrenic dyssynergia (APD) – when the diaphragm moves downward instead of upward, causing visible abdominal distention

• Specialized breathing technique developed in Barcelona that retrain the diaphragm for bloating relief (Barba E et al 2024) - see video link below

• The importance of normalizing healthy pooping habits from childhood through education & tools like toileting stools (e.g. Squatty Potty)

• Warning signs for parents about childhood constipation – including stool leakage, straining, & urinary problems (Tran DL et al 2023)

• How yoga can support gut health through mindful movement, core engagement, & stress reduction

Yoga videos:

Yoga For Digestion Flow| Yoga With Adriene (26 mins)

Yoga for Bloating, Digestion, Ulcerative Colitis, IBD & IBS (12 mins)

Check out Dr. Wang's children's book Boo Can't Poo, which helps normalize healthy pooping habits for kids while educating parents too.

References:

Wang XJ, Camilleri M. Personalized medicine in functional gastrointestinal disorders: Understanding pathogenesis to increase diagnostic and treatment efficacy. World J Gastroenterol. 2019 Mar 14;25(10):1185-1196.

Barba E, Livovsky DM, Accarino A, Azpiroz F. Thoracoabdominal Wall Motion-Guided Biofeedback Treatment of Abdominal Distention: A Randomized Placebo-Controlled Trial. Gastroenterology. 2024;167(3):538-546.e1.

Specialized breathing technique for abdominal distention: Video Demonstration

Tran DL, Sintusek P. Functional constipation in children: What physicians should know. World J Gastroenterol. 2023 Feb 28;29(8):1261-1288.

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.

Fermented foods offer surprising health benefits with science showing they can increase gut microbial diversity in ways other dietary interventions cannot.

• Expert Elisa Caffrey clarifies what qualifies as fermented food: substrate + microbes + time
• While touted as a source of probiotics, most fermented foods don't technically contain probiotics, which require specific strain characterization and known health benefits
•Different types of fermentation are used in food production: lactic acid bacteria ferment carbohydrates in sauerkraut and yogurt; acetic acid bacteria oxidize ethanol into acetic acid in kombucha; and filamentous fungi such as Aspergillus oryzae and Rhizopus species are involved in the fermentation of miso and tempeh, respectively.
• Fermented foods may benefit gut health through microbial derived metabolites rather than just the microbes in the food or beverage.
• Consider starting with yogurt if you are a newcomer and have fun exploring kimchi, sauerkraut and other options for fermented food variety.
• Most fermented foods are safe, though some considerations exist for those with histamine intolerance or sodium restrictions
• Variety is key – consuming diverse fermented foods appears to help maximize potential benefits
• The fermentation process may have mental health benefits beyond nutrition though more research is needed

Try incorporating fermented foods gradually into your diet and experiment with different types to find what works for your body and taste preferences.

 Let us know what makes your taste buds (and gut) happy! 

This episode has been sponsored by Activia. Check out their Gut Health Tool Kit here and A Gut Friendly Meal plan here.

References:

Caffrey EB et al. Unpacking food fermentation: Clinically relevant tools for fermented food identification and consumption

Gaudiest G et al. Microbial and metabolic characterization of organic artisanal sauerkraut fermentation and study of gut health-promoting properties of sauerkraut brine

Wastyk HC et al. Gut microbiota-targeted diets modulate human immune status (high fiber vs fermented food study)

Nielson ES et al. Lacto-fermented sauerkraut improves symptoms in IBS patients independent of product pasteurisation - A pilot study  

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.