Irritable bowel syndrome (IBS) is a functional bowel disorder characterized by abdominal pain, bloating, and either constipation, diarrhea, or both constipation and diarrhea [1]. While the exact etiology of IBS has not been well understood, rapid advancement in research has pointed to disordered intestinal motility, visceral hypersensitivity, post infectious reactivity, brain-gut interaction, dysbiosis and bacterial overgrowth, food sensitivities, carbohydrate malabsorption, and intestinal inflammation as contributing factors to the development of IBS [1]. Our IBS protocol is based on research surrounding each of these characterizations using novel solutions for optimizing the microbial ecosystem, reducing inflammation, and supporting digestion.


Week 1+


Zenbiome Dual

  • Directions:
      • Take 2 capsules daily with food
      • Some patients may experience some gut changes or discomfort during the first 4 weeks. This is temporary and is an indication that the probiotic cultures are beginning to take effect.
  • Supportive evidence:
      • Bifidobacterium longum 35624 has been clinically shown to reduce disease severity and improve the quality of life of patients with IBS/functional GI disorders over the course of 30 days. This improvement has been seen particularly in those with the most severe forms of the disorder [22]. B. longum 35624 has also been shown to normalize abnormal proinflammatory cytokine ratios (IL-10/IL-12) after 8 weeks of supplementation [23].
      • Bidifobacterium longum 1714 has been clinically shown to attenuate anxiety levels following exposure to a stressor. Research participants reported significantly lower levels of total cortisol output and perceived daily stress [24]. B. longum 1714 is also shown to increase theta and alpha brain waves during social stress and at rest. Increasing theta and alpha waves at rest was associated with reduced mental fatigue and increased energy and vitality scores [25].
Zenbiome DUAL


  • Directions:
      • Week 1: take 1 capsule every other day
      • Week 2: take 1 capsule daily
      • Week 3+: take 2 capsules per day
      • Continue until symptoms improve at which point a maintenance dose of 2 capsules, 2-3 times per week is recommended
  • Supportive evidence:
      • MegaSporeBiotic normalizes gut bacterial species through antimicrobial activity, competitive exclusion, and ability to increase beneficial species. In an IBS study comparing MegaSporeBiotic to antibiotic therapy, MegaSporeBiotic was shown to improve IBS severity scores better than rifaximin. This was achieved without the negative side effects of antibiotic therapy. Additionally, MegaSporeBiotic users achieved better rectal volume sensations support which highlights the improvement in gut-brain connectivity [2-7].


  • Directions:
      • Take two capsules twice a day with food.
      • If experiencing diarrhea, increase by two capsules per day to a therapeutic dose of 5 grams, as tolerated.
  • Supportive evidence:
      • Serum-derived bovine immunoglobulins reduce antigen load, dampen immune activation, improve gut barrier function and result in improved QoL scores including overall management of IBS and decreased daily stool frequency [7]. Additionally, serum derived immunoglobulins have a high binding affinity for a variety of endo- and exotoxins secreted by microorganisms [8].


  • Directions:
      • Take 2 soft gels per day with a meal.
  • Supportive evidence:
      • Supports intestinal mucosa production and goblet cell differentiation [9-11]. Addresses intestinal barrier and systemic inflammation [9-11]. Contains prebiotic properties that can support dysbiosis and helpful bacterial strains while reducing LPS-producing bacteria like Enterobacteria, often elevated in IBS [12,13].

Week 1-12+



  • Directions:
      • Take 2 capsules 15-30 minutes before meals containing fermentable oligosaccharides, disaccharides, and/or monosaccharides 2-3 times per day.
      • Recommend in 1-3 month increments as long-term use will result in decreased microbial diversity.
  • Supportive evidence:
      • FODMAP specific enzyme blend that supports the digestion of fermentable oligosaccharides, disaccharides, and/or monosaccharides. The enzymatic breakdown of fermentable fibers reduces consumption by bacterial species in the small intestine that contribute to gas, boating, and pain [14-17].

Additional nutraceutical considerations:

  • Zenbiome Cope to support stress and anxiety [18-21].
Zenbiome Cope
  • MegaPre to feed beneficial bacteria and increase production of SCFA like butyrate.
  • MegaMucosa to support mucosal health and integrity which can be impacted by mucin degrading bacteria often found in the microbiome of IBS patients.


The Fullscript Integrative Medical Advisory team has developed or collected these protocols from practitioners and supplier partners to help health care practitioners make decisions when building treatment plans. By adding this protocol to your Fullscript template library, you understand and accept that the recommendations in the protocol are for initial guidance and may not be appropriate for every patient.

View protocol in-app


  1. Saha L. Irritable bowel syndrome: pathogenesis, diagnosis, treatment, and evidence-based medicine. World J Gastroenterol. 2014 Jun 14;20(22):6759-73. doi: 10.3748/wjg.v20.i22.6759. PMID: 24944467; PMCID: PMC4051916.
  2. Catinean A, et al. Bacillus spp. Spores—A Promising Treatment Option for Patients with Irritable Bowel Syndrome. Nutrients. 2019; 11:1968;1-10.
  3. McFarlin BK, et al. Oral spore-based probiotic supplementation was associated with reduced incidence of post-prandial dietary endotoxin, triglycerides, and disease risk biomarkers. World J Gastrointest Pathophysiol. 2017; 8(3):117–126.
  4. Stein T. Bacillus subtilis antibiotics: structures, syntheses and specific functions. Molecular Microbiology. 2005;56(4):845-857.
  5. Dong T, Van P, Cutting S. Bacillus Probiotics.Nutra Foods. 2009;8(2):7-14.
  6. Suva MA, et al. Novel insight on probiotic Bacillus subtilis: Mechanism of action and clinical applications. Jour Curr Res in Sci Med. 2016; 2(2):65-72.
  7. Shaw AL, Tomanelli A, Bradshaw TP, Petschow BW, Burnett BP. Impact of serum-derived bovine immunoglobulin/protein isolate therapy on irritable bowel syndrome and inflammatory bowel disease: a survey of patient perspective. Patient Prefer Adherence. 2017 May 31;11:1001-1007. doi: 10.2147/PPA.S134792. PMID: 28615929; PMCID: PMC5460652. 
  8. Asmuth DM, Ma ZM, Albanese A, et al. Oral serum-derived bovine immunoglobulin improves duodenal immune reconstitution and absorption function in patients with HIV enteropathy. AIDS. 2013;27(14):2207-2217. doi:10.1097/QAD.0b013e328362e54c
  9. Prossomariti, et al. Short-term treatment with eicosapentaenoic acid improves inflammation and affects colonic differentiation markers and microbiota in patients with ulcerative colitis. Scientific Reports. 2017; 7: e7458. DOI:10.1038/s41598-017-07992-1
  10. Fonseca, et al. Comparative effects of the ω3 polyunsaturated fatty acid derivatives resolvins E1 and D1 and protectin DX in models of inflammation and pain. Journal of Inflammation Research. 2017;10:119–133.
  11. Fu Y, Wang Y, Gao H, et al. Associations among Dietary Omega-3 Polyunsaturated Fatty Acids, the Gut Microbiota, and Intestinal Immunity. Mediators Inflamm. 2021;2021:8879227. Published 2021 Jan 2. doi:10.1155/2021/8879227
  12. Costantini L, Molinari R, Farinon B, Merendino N. Impact of Omega-3 Fatty Acids on the Gut Microbiota. Int J Mol Sci. 2017;18(12):2645. Published 2017 Dec 7. doi:10.3390/ijms18122645
  13. Pittayanon R, Lau JT, Yuan Y, Leontiadis GI, Tse F, Surette M, Moayyedi P. Gut Microbiota in Patients With Irritable Bowel Syndrome-A Systematic Review. Gastroenterology. 2019 Jul;157(1):97-108. doi: 10.1053/j.gastro.2019.03.049. Epub 2019 Mar 30. PMID: 30940523.
  14. Di Stefano, et al. The Effect of Oral α-Galactosidase on Intestinal Gas Production and Gas-Related Symptoms. Digestive Diseases and Sciences. 2006; 52(1):78–83.
  15. Tuck CJ, et al. Increasing Symptoms in Irritable Bowel Symptoms with Ingestion of Galacto-Oligosaccharides Are Mitigated by α-Galactosidase Treatment. Am J Gastroenterol. 2018 Jan;113(1):124-134
  16. Komericki, et al. Oral Xylose Isomerase Decreases Breath Hydrogen Excretion and Improves Gastrointestinal Symptoms in Fructose Malabsorption – a Double-Blind, Placebo-Controlled Study. Alimentary Pharmacology & Therapeutics. 2012; 36(10): 980–987.
  17. Chi, et al. Inulinase-Expressing Microorganisms and Applications of Inulinases. Applied Microbiology and Biotechnology. 2009.; 82(2): 211-220
  18. Savignac, et al. Bifidobacteria exert strain-specific effects on stress-related behavior and physiology in BALB/cmice. Neurogastroenterology & Motility. 2014;26(11), 1615-1627.
  19. Wang, et al. Bifidobacterium longum 1714TM Strain Modulates Brain Activity of HealthyVolunteers During Social Stress. The American Journal of Gastroenterology. 2019; 114(7): 1152-1162.
  20. Stough, et al. The Effect of 90 Day Administration of a High Dose Vitamin B-Complex on Work Stress.” Human Psychopharmacology: Clinical and Experimental. 2011; 26(7):470–476
  21. Lopresti, et al. Efficacy of a Standardised Saffron Extract (Affron®) as an Add-on
  22. Sabaté JM, Iglicki F. Effect of Bifidobacterium longum 35624 on disease severity and quality of life in patients with irritable bowel syndrome. World Journal of Gastroenterology 2022; 28(7): 732 744. 
  23. O’Mahony L, et al. Lactobacillus and Bifidobacterium in irritable bowel syndrome: symptom responses and relationship to cytokine profiles. Gastroenterology. 2005; 128(3): 541 551. 
  24. Allen AP, et al. Bifidobacterium longum 1714 as a translational psychobiotic modulation of stress, electrophysiology and neurocognition in healthy volunteers. Translational Psychiatry 2016; 6(11): e939.
  25. Wang H, et al . Bifidobacterium longum 1714 ™Strain Modulates Brain Activity of Healthy Volunteers During Social Stress. American Journal of Gastroenterology. 2019; 114(7): 1152 11622.

*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.