Small intestine bacterial overgrowth (SIBO) is a disorder characterized by an excessive concentration of bacteria in the small intestine (exceeding 105 organisms/mL). Patients with SIBO commonly report abdominal pain, flatulence, bloating, and diarrhea, and may experience malabsorption and weight loss in more severe cases.1 The standard regimen to manage SIBO has been antibiotic therapy, but this may disrupt the normal balance of the gut microbiota and can increases the risk of developing antibiotic resistance. Further, the antibiotics used are often bacteriostatic, not bacteriocidal, and thus may require repeated treatments.2
Probiotics have therapeutic potential to manage SIBO because they have been shown to inhibit translocation of bacteria (and therefore the bacterial endotoxins) from the gut to the circulation, suppress colonization of pathogenic bacteria, enhance gut barrier integrity, and restore the equilibrium of the altered gut microbiota.3
Published in the April issue of the Journal of Clinical Gastroenterology is the first systematic review and meta-analysis to appraise the value of probiotics in the prevention and treatment of SIBO. Researchers conducted a thorough literature search of clinical trials and identified 18 clinical studies for the meta-analysis. The pooled analysis found that probiotics were remarkably effective for the treatment of SIBO:4
Overall, the SIBO decontamination rate was 62.8% for probiotics. Specifically, the SIBO decontamination rate was 53.5% for probiotics alone—which was comparable to that observed in a meta-analysis5 on antibiotics (51.1%)—and 85.5% for probiotics plus antibiotics. Probiotics substantially decreased the H2 concentration measured in the hydrogen breath test (a validated tool to diagnose SIBO). Further, probiotics significantly alleviated the abdominal pain as assessed by the abdominal pain scores.
Why is this clinically important?
- Clinicians who seek treatment options other than antibiotics in SIBO management, probiotics supplementation could effectively decontaminate SIBO, decrease H2 concentration, and relieve abdominal pain.
- Probiotics do not have adverse effects associated with antibiotics treatment.
- In cases where antibiotics are necessary, adding probiotics may be a promising approach as the combination could amplify the treatment effect.
- Dukowicz AC, Lacy BE, Levine GM. Small intestinal bacterial overgrowth: a comprehensive review. Gastroenterol Hepatol (N Y) 2007;3:112-122.
- Krajicek EJ, Hansel SL. Small Intestinal Bacterial Overgrowth: A Primary Care Review. Mayo Clin Proc 2016;91:1828-1833.
- Ng SC, Hart AL, Kamm MA, Stagg AJ, Knight SC. Mechanisms of action of probiotics: recent advances. Inflamm Bowel Dis 2009;15:300-310.
- Zhong C, Qu C, Wang B, Liang S, Zeng B. Probiotics for Preventing and Treating Small Intestinal Bacterial Overgrowth: A Meta-Analysis and Systematic Review of Current Evidence. J Clin Gastroenterol 2017;51:300-311.
- Shah SC, Day LW, Somsouk M, Sewell JL. Meta-analysis: antibiotic therapy for small intestinal bacterial overgrowth. Aliment Pharmacol Ther 2013;38:925-934.