Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Meta-Analysis
. 2020 Feb;115(2):190-201.
doi: 10.14309/ajg.0000000000000504.

Small Intestinal Bacterial Overgrowth in Irritable Bowel Syndrome: A Systematic Review and Meta-Analysis of Case-Control Studies

Ayesha Shah  1   2   3 , Nicholas J Talley  4 , Mike Jones  5 , Bradley J Kendall  1   2 , Natasha Koloski  1   4 , Marjorie M Walker  4 , Mark Morrison  1   2   6 , Gerald J Holtmann  1   2   3
Affiliations
Meta-Analysis

Small Intestinal Bacterial Overgrowth in Irritable Bowel Syndrome: A Systematic Review and Meta-Analysis of Case-Control Studies

Ayesha Shah et al. Am J Gastroenterol. 2020 Feb.

Abstract

Introduction: We conducted a systematic review and meta-analysis to compare the prevalence of small intestinal bacterial overgrowth (SIBO) in patients with irritable bowel syndrome (IBS) and controls.

Methods: Electronic databases were searched up to December 2018 for studies reporting SIBO prevalence in patients with IBS. Prevalence rates, odds ratios (ORs), and 95% confidence intervals (CIs) of SIBO in patients with IBS and controls were calculated.

Results: We included 25 studies with 3,192 patients with IBS and 3,320 controls. SIBO prevalence in patients with IBS was significantly increased compared with controls (OR = 3.7, 95% CI 2.3-6.0). In studies using only healthy controls, the OR for SIBO in patients with IBS was 4.9 (95% CI 2.8-8.6). With breath testing, SIBO prevalence in patients with IBS was 35.5% (95% CI 33.6-37.4) vs 29.7% (95% CI 27.6-31.8) in controls. Culture-based studies yielded a SIBO prevalence of 13.9% (95% CI 11.5-16.4) in patients with IBS and 5.0% (95% CI 3.9-6.2) in controls with a cutoff value of 10 colony-forming units per milliliter vs 33.5% (95% CI 30.1-36.9) in patients with IBS and 8.2% (95% CI 6.8-9.6) in controls with a cutoff value of 10 colony-forming unit per milliliter, respectively. SIBO prevalence diagnosed by lactulose breath test is much greater in both patients with IBS (3.6-fold) and controls (7.6-fold) compared with glucose breath test. Similar difference is seen when lactulose breath test is compared with culture methods. OR for SIBO in patients with IBS-diarrhea compared with IBS-constipation was 1.86 (95% CI 1.83-2.8). Methane-positive breath tests were significantly more prevalent in IBS-constipation compared with IBS-diarrhea (OR = 2.3, 95% CI 1.2-4.2). In patients with IBS, proton pump inhibitor was not associated with SIBO (OR = 0.8, 95% CI 0.5-1.5, P = 0.55).

Discussion: This systematic review and meta-analysis suggests a link between IBS and SIBO. However, the overall quality of the evidence is low. This is mainly due to substantial "clinical heterogeneity" due to lack of uniform selection criteria for cases and controls and limited sensitivity and specificity of the available diagnostic tests.

PubMed Disclaimer

References

    1. Corazza GR, Menozzi MG, Strocchi A, et al. The diagnosis of small bowel bacterial overgrowth: Reliability of jejunal culture and inadequacy of breath hydrogen testing. Gastroenterology 1990;98:302–9.
    1. Paik CN, Choi MG, Lim CH, et al. The role of small intestinal bacterial overgrowth in postgastrectomy patients. Neurogastroenterol Motil 2011;23:e191–6.
    1. Khoshini R, Dai SC, Lezcano S, et al. A systematic review of diagnostic tests for small intestinal bacterial overgrowth. Dig Dis Sci 2008;53:1443–54.
    1. Rezaie A, Buresi M, Lembo A, et al. Hydrogen and methane-based breath testing in gastrointestinal disorders: The North American consensus. Am J Gastroenterol 2017;112:775–84.
    1. Romagnuolo J, Schiller D, Bailey RJ. Using breath tests wisely in a gastroenterology practice: An evidence-based review of indications and pitfalls in interpretation. Am J Gastroenterol 2002;97:1113–26.

Publication types

Substances

LinkOut - more resources