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🦠 Awesome Gut Health Resources

Last Updated Evidence-Based Contributions Welcome

A curated collection of evidence-based gut health resources — research papers, tools, protocols, apps, and guides for understanding and optimizing your gut microbiome.

Your gut microbiome contains trillions of microorganisms that influence digestion, immunity, mental health, metabolism, and nearly every system in your body. Despite the hype surrounding gut health, separating science from marketing noise is harder than ever.

This repository cuts through the noise. Every resource listed here is grounded in peer-reviewed research and organized for practical use. For a comprehensive, evidence-based walkthrough of gut health fundamentals, protocols, and product recommendations, see the Health Secrets gut health guide.

Table of Contents

Understanding the Microbiome

Foundational resources for understanding gut microbiology, dysbiosis, and intestinal permeability.

Resource Type Description Evidence Grade
Human Microbiome Project (NIH) Database The NIH’s comprehensive characterization of the human microbiome across body sites A
Gut Microbiota for Health Knowledge Hub World Gastroenterology Organisation resource hub for microbiome science and clinical applications A
American Gut Project Citizen Science One of the largest crowd-sourced microbiome studies; explore population-level microbiome data A
Valdes et al., 2018 - “Role of the gut microbiota in nutrition and health” Review Paper Landmark BMJ review covering microbiome composition, diversity, and health implications A
David et al., 2014 - “Diet rapidly alters the human gut microbiome” Research Paper Demonstrated that dietary changes shift microbiome composition within days A
Camilleri, 2019 - “Leaky gut: mechanisms and clinical implications” Review Paper Comprehensive review of intestinal permeability measurement and clinical significance A
Microbiome 2.0: Lessons from 2024 Gut Microbiota Summit Conference Report Latest consensus from leading microbiome researchers on clinical applications A

Further Reading

Probiotics & Fermented Foods

Research on specific probiotic strains, clinical efficacy, fermented food science, and supplementation guidelines.

Resource Type Description Evidence Grade
ISAPP - International Scientific Association for Probiotics and Prebiotics Organization Leading scientific body for probiotics/prebiotics; publishes consensus statements and guidelines A
NIH - Probiotics: What You Need to Know Government Guide NCCIH overview of probiotic science, safety, and clinical evidence A
Wastyk et al., 2021 - “Gut-microbiota-targeted diets modulate human immune status” Research Paper Stanford study showing fermented food diets increase diversity and decrease inflammatory markers A
Shi et al., 2016 - “Beneficial properties of probiotics” Review Paper Comprehensive review of probiotic mechanisms, strain-specific benefits, and clinical applications A
Iovino et al., 2024 - “Functional abdominal bloating and gut microbiota” Review Paper Meta-analysis showing significant effect of probiotics on bloating scores in IBS B
Clinical Guide to Probiotic Products (probioticchart.ca) Clinical Tool Canadian guide matching probiotic strains to clinical indications with evidence grades A

Key Probiotic Strains Reference

Strain Primary Benefits Evidence Level Typical Dose
Lactobacillus rhamnosus GG Diarrhea, IBS, immune support A — Multiple RCTs 10-20B CFU
Lactobacillus plantarum 299v IBS, gut barrier, inflammation A — Multiple RCTs 10B CFU
Bifidobacterium longum 35624 IBS (all subtypes), bloating A — Multiple RCTs 1B CFU
Bifidobacterium lactis BB-12 Immune support, regularity A — Multiple RCTs 10B CFU
Saccharomyces boulardii Antibiotic-associated diarrhea, C. diff A — Multiple RCTs 250-500mg
Lactobacillus helveticus R0052 Anxiety, stress (psychobiotic) B — Emerging evidence 3-10B CFU

Further Reading

Prebiotics & Dietary Fiber

Resources on prebiotic types, fiber science, short-chain fatty acid production, and dietary optimization.

Resource Type Description Evidence Grade
Gibson et al., 2017 - “Expert consensus: The ISAPP definition of prebiotics” Consensus Paper The definitive scientific definition and classification of prebiotics A
Slavin, 2013 - “Fiber and prebiotics: mechanisms and health benefits” Review Paper Comprehensive review of fiber types, fermentation, SCFA production, and health outcomes A
Silva et al., 2020 - “Role of SCFAs in gut-brain communication” Review Paper How butyrate, acetate, and propionate influence brain function through the gut-brain axis A
Sonnenburg & Sonnenburg, 2014 - “Starving our microbial self” Research Paper How low-fiber Western diets drive microbiome extinction across generations A
Holscher, 2017 - “Dietary fiber and prebiotics and the gut microbiota” Review Paper How specific fibers selectively enrich beneficial bacteria A

Prebiotic Food Sources

Prebiotic Type Top Food Sources Primary Bacteria Fed
Inulin Chicory root, Jerusalem artichokes, garlic, onions, leeks Bifidobacterium
FOS Bananas, asparagus, onions, garlic Bifidobacterium, Lactobacillus
GOS Legumes, lentils, chickpeas Bifidobacterium
Resistant Starch Cooked & cooled potatoes/rice, green bananas, oats Butyrate producers
Pectin Apples, citrus fruits, berries Bifidobacterium, Bacteroides
Beta-glucan Oats, barley, mushrooms Lactobacillus, butyrate producers

Gut-Brain Axis & Mental Health

Research connecting the microbiome to mood, cognition, stress, and neurological conditions.

Resource Type Description Evidence Grade
Zheng et al., 2024 - “Microbiota-gut-brain axis in neurodegenerative diseases” Review Paper Comprehensive review of MGBA pathways in neurodegeneration — communication mechanisms and therapeutic targets A
Carabotti et al., 2015 - “The gut-brain axis” Review Paper Foundational review of enteric microbiota interactions with central and enteric nervous systems A
Stanford Medicine, 2025 - “The gut-brain connection” Expert Article Stanford researchers describe the gut-brain relationship in anxiety, long COVID, and Parkinson’s A
Dinan & Cryan, 2013 - “Psychobiotics: a novel class of psychotropic” Research Paper Coined the term “psychobiotics” — probiotics that benefit mental health A
Breit et al., 2018 - “Vagus nerve in psychiatric and inflammatory disorders” Review Paper How vagal tone mediates the gut-brain connection in mental health A
Yano et al., 2015 - “Gut microbiota regulate host serotonin biosynthesis” Research Paper Landmark study showing gut bacteria regulate 90% of serotonin production A

Further Reading

Gut Healing Protocols

Step-by-step evidence-based approaches to restoring gut health.

The 4R Protocol (Remove, Repair, Reinoculate, Rebalance)

The most widely used functional medicine framework for gut restoration:

Phase 1 — REMOVE (Week 1)

Phase 2 — REPAIR (Week 2)

Phase 3 — REINOCULATE (Week 3)

Phase 4 — REBALANCE (Week 4)

Protocol Resources

Resource Type Description
Lomer, 2015 - “Review: the aetiology, diagnosis, mechanisms and clinical evidence for food intolerance” Review Evidence for elimination diets in functional GI disorders
Monda et al., 2017 - “Exercise modifies the gut microbiota” Research Paper How physical activity improves microbiome diversity
Karl et al., 2018 - “Effects of stressors on the gut microbiota” Review Paper How stress impacts the microbiome and recovery strategies

Tools & Apps

Practical tools for tracking, testing, and optimizing gut health.

Tool Type Description Cost
Viome Microbiome Testing At-home gut microbiome test with personalized food and supplement recommendations $$
Zoe Microbiome + Nutrition Combines microbiome test with blood sugar and blood fat analysis for personalized nutrition $$$
Cara Care Symptom Tracker Free app for tracking digestive symptoms, meals, stress, and stool quality Free
Monash FODMAP Diet Tool The gold-standard FODMAP diet app from Monash University researchers $
Bristol Stool Chart Assessment Tool Standardized classification for stool consistency — used clinically worldwide Free

📋 Free Tools

Put these protocols into practice with free interactive Notion templates:

→ Browse all free health tools on Notion

Contributing

Contributions are welcome! If you’d like to add a resource:

  1. Fork this repository
  2. Ensure the resource is peer-reviewed or from a recognized medical institution
  3. Include an evidence grade (A = strong RCT/meta-analysis, B = moderate evidence, C = preliminary/animal studies)
  4. Submit a pull request with a brief description of why the resource is valuable

Please do not submit:

Disclaimer

This repository is for educational purposes only. The information provided does not constitute medical advice. Consult a qualified healthcare professional before starting any health protocol.

References

  1. Valdes, A.M. et al. “Role of the gut microbiota in nutrition and health.” BMJ, 2018. https://doi.org/10.1136/bmj.k2179
  2. David, L.A. et al. “Diet rapidly and reproducibly alters the human gut microbiome.” Nature, 2014. https://doi.org/10.1038/nature12820
  3. Camilleri, M. “Leaky gut: mechanisms, measurement and clinical implications in humans.” Gut, 2019. https://doi.org/10.1136/gutjnl-2019-318427
  4. Wastyk, H.C. et al. “Gut-microbiota-targeted diets modulate human immune status.” Cell, 2021. https://doi.org/10.1016/j.cell.2021.06.019
  5. Shi, L.H. et al. “Beneficial properties of probiotics.” Tropical Life Sciences Research, 2016. https://pmc.ncbi.nlm.nih.gov/articles/PMC5031164/
  6. Iovino, P. et al. “Functional abdominal bloating and gut microbiota: an update.” Microorganisms, 2024. https://www.mdpi.com/2076-2607/12/8/1669
  7. Yano, J.M. et al. “Indigenous bacteria from the gut microbiota regulate host serotonin biosynthesis.” Cell, 2015. https://doi.org/10.1016/j.cell.2015.02.047
  8. Zheng, Y. et al. “Microbiota-gut-brain axis in neurodegenerative diseases.” Signal Transduction and Targeted Therapy, 2024. https://www.nature.com/articles/s41392-024-01743-1
  9. Carabotti, M. et al. “The gut-brain axis.” Annals of Gastroenterology, 2015. https://pmc.ncbi.nlm.nih.gov/articles/PMC4367209/
  10. Breit, S. et al. “Vagus nerve as modulator of the brain-gut axis.” Frontiers in Psychiatry, 2018. https://doi.org/10.3389/fpsyt.2018.00044
  11. Dinan, T.G. et al. “Psychobiotics: a novel class of psychotropic.” Biological Psychiatry, 2013. https://doi.org/10.1016/j.biopsych.2013.05.001
  12. Gibson, G.R. et al. “Expert consensus: The ISAPP definition of prebiotics.” Nature Reviews Gastroenterology & Hepatology, 2017. https://doi.org/10.1038/nrgastro.2017.75
  13. Slavin, J. “Fiber and prebiotics: mechanisms and health benefits.” Nutrients, 2013. https://doi.org/10.3390/nu5041417
  14. Silva, Y.P. et al. “The role of short-chain fatty acids from gut microbiota in gut-brain communication.” Frontiers in Endocrinology, 2020. https://doi.org/10.3389/fendo.2020.00025
  15. Sonnenburg, E.D. & Sonnenburg, J.L. “Starving our microbial self.” Cell, 2014. https://doi.org/10.1016/j.cell.2014.12.035
  16. Holscher, H.D. “Dietary fiber and prebiotics and the gut microbiota.” Gut Microbes, 2017. https://doi.org/10.1080/19490976.2017.1290756
  17. Monda, V. et al. “Exercise modifies the gut microbiota with positive health effects.” Oxidative Medicine and Cellular Longevity, 2017. https://doi.org/10.1155/2017/3831972
  18. Karl, J.P. et al. “Effects of psychological, environmental and physical stressors on the gut microbiota.” Frontiers in Microbiology, 2018. https://doi.org/10.3389/fmicb.2018.02013
  19. Satokari, R. “High intake of sugar and the balance between pro- and anti-inflammatory gut bacteria.” Nutrients, 2020. https://doi.org/10.3390/nu12051348
  20. Suez, J. et al. “Artificial sweeteners induce glucose intolerance by altering the gut microbiota.” Nature, 2014. https://doi.org/10.1038/nature13793
  21. Panda, C. et al. “Metabolic reset purification program improves antioxidant balance and gut microbiome.” Frontiers in Nutrition, 2025. https://pmc.ncbi.nlm.nih.gov/articles/PMC12376428/

Further Reading