
Daily Gut Foundation
About this protocol
Where to start
Start with a soluble fiber supplement if your dietary fiber intake is low (under 25-30 g/day for most adults). Psyllium or partially hydrolyzed guar gum (PHGG) are the best-evidenced. Start at half-dose for the first week to let your microbiome adjust — full dose right away causes gas and bloating in most people.
Add a multistrain probiotic if you've recently been on antibiotics, are traveling, or have ongoing low-grade gut symptoms. Look for products that name specific strains (Lactobacillus rhamnosus GG, Bifidobacterium lactis BB-12, etc.) rather than vague "10 billion CFU" claims.
Add L-glutamine if you have ongoing barrier-function concerns — IBS, food sensitivities, or post-antibiotic recovery.
Saccharomyces boulardii is the most targeted — only worth adding if you have a specific reason (antibiotic course, recurrent diarrhea, traveler's diarrhea prevention). Not a daily supplement for everyone.
If symptoms persist after 6-8 weeks of this foundation, see a gastroenterologist. Gut conditions are over-diagnosed and under-investigated in equal measure.
4 nutrients
Start here
Strongest evidence — the foundation of the stack.
Soluble Fiber (Psyllium or PHGG)
5-10 g, with breakfast (start at half-dose for the first week)Soluble fiber is fermented by gut bacteria into short-chain fatty acids (butyrate, propionate, acetate) that feed colonocytes and modulate the gut microbiome. Psyllium has the strongest evidence for constipation, cholesterol reduction, and glycemic control. Partially hydrolyzed guar gum (PHGG) is gentler on sensitive guts and well-tolerated in IBS. Take with plenty of water.[1, 2, 3]
Multistrain Probiotic
10-50 billion CFU daily, with breakfastProbiotics work strain-by-strain, not category-wide. The strongest evidence is for prevention of antibiotic-associated diarrhea (Lactobacillus rhamnosus GG, S. boulardii), shortening of acute infectious diarrhea, and modest improvement in IBS symptoms. Choose products that explicitly name their strains. Refrigerated products generally have better viable CFU counts at expiry.[4, 5, 6]
Add if needed
Add these only if the foundation isn't enough.
L-Glutamine
5 g, twice daily on an empty stomachL-glutamine is the primary fuel source for enterocytes (intestinal epithelial cells). Trial evidence shows benefit for intestinal permeability and IBS symptoms, particularly in post-infectious IBS. Effect sizes are modest and the protocol typically runs 4-8 weeks. Not necessary as a daily forever-supplement for most people.[7, 8, 9]
Experimental
Emerging evidence — try last, only if curious.
Saccharomyces boulardii
5-10 billion CFU daily during antibiotic course or for 7-14 days of acute useSaccharomyces boulardii is a non-pathogenic yeast (technically a probiotic, but not a bacterium). The trial evidence is targeted: prevention of antibiotic-associated diarrhea, reduction of Clostridium difficile recurrence, and traveler's diarrhea. Not a daily supplement for everyone — use it for specific situations.[10, 11, 12]
Warnings
Lifestyle improvements
Diversity of plant foods beats supplements
The American Gut Project found that people eating 30+ different plant species per week had measurably more diverse microbiomes than those eating fewer than 10. No probiotic supplement matches that intervention. Aim for variety, not perfection.
Fermented foods
Yogurt, kefir, sauerkraut, kimchi, and miso deliver live cultures with food matrix benefits that capsules don't replicate. A daily serving is a reasonable target.
Sleep, stress, and the gut-brain axis
Chronic stress and poor sleep measurably alter gut motility, permeability, and microbiome composition. The supplement stack works best on top of these basics, not as a substitute.
Hydration
Adequate water intake (especially when adding fiber) is essential. Insufficient hydration with high fiber causes constipation and bloating.
Identify trigger foods honestly
Many "gut issues" are specific food intolerances (lactose, fructans, gluten) rather than dysbiosis. A short structured elimination trial (3-4 weeks removing one suspect, then reintroducing) is more informative than chronic supplementation.
When to see a doctor
Persistent symptoms beyond 8 weeks of consistent foundation work, blood in stool, unexplained weight loss, family history of colon cancer, or symptoms severe enough to disrupt daily life all warrant proper medical evaluation, not more supplements.
References
- Psyllium — supplement research overviewExamine.com link
- McRorie JW Jr, McKeown NM. Understanding the Physics of Functional Fibers in the Gastrointestinal Tract: An Evidence-Based Approach to Resolving Enduring Misconceptions. J Acad Nutr Diet. 2017;117(2):251-264.PubMed link
- Rao TP, et al. Effect of fiber-rich foods on the visceral fat in adults: a randomized controlled trial. Nutrition. 2015;31(1):103-108.PubMed link
- Probiotics — supplement research overviewExamine.com link
- Hempel S, et al. Probiotics for the prevention and treatment of antibiotic-associated diarrhea: a systematic review and meta-analysis. JAMA. 2012;307(18):1959-1969.PubMed link
- Ford AC, et al. Systematic review with meta-analysis: the efficacy of prebiotics, probiotics, synbiotics and antibiotics in irritable bowel syndrome. Aliment Pharmacol Ther. 2018;48(10):1044-1060.PubMed link
- L-Glutamine — supplement research overviewExamine.com link
- Zhou Q, et al. Randomised placebo-controlled trial of dietary glutamine supplements for postinfectious irritable bowel syndrome. Gut. 2019;68(6):996-1002.PubMed link
- Achamrah N, et al. Glutamine and the regulation of intestinal permeability: from bench to bedside. Curr Opin Clin Nutr Metab Care. 2017;20(1):86-91.PubMed link
- Saccharomyces boulardii — supplement research overviewExamine.com link
- Szajewska H, Kołodziej M. Systematic review with meta-analysis: Saccharomyces boulardii in the prevention of antibiotic-associated diarrhoea. Aliment Pharmacol Ther. 2015;42(7):793-801.PubMed link
- McFarland LV. Systematic review and meta-analysis of Saccharomyces boulardii in adult patients. World J Gastroenterol. 2010;16(18):2202-2222.PubMed link
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Coming to App StoreDisclaimer: These statements have not been evaluated by the FDA. This protocol is educational, not a substitute for personalized medical advice. Talk to your doctor before starting any new supplement regimen — especially if you're pregnant, breastfeeding, on medications, or managing a chronic condition. Last updated 5/20/2026.