Helicobacter pylori Infection and Irritable Bowel Syndrome: A Systematic Review and Meta-Analysis With a Narrative Review of the Evidence for Inflammatory Bowel Disease

Helicobacter pylori (H. pylori) infection has been extensively studied for its potential association with irritable bowel syndrome (IBS), with prior meta-analyses reporting inconsistent findings. This study aimed to perform a systematic review and meta-analysis of observational studies restricted to those providing reconstructable 2×2 contingency data, thereby enhancing transparency and reproducibility. A systematic search of PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials (CENTRAL) was conducted from database inception to present. Eligible studies were observational (cross-sectional or case-control), included adult populations with appropriate control groups, and reported extractable 2×2 data for H. pylori infection status. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using a random-effects model. Four studies met the inclusion criteria for IBS. The pooled analysis demonstrated no statistically significant association between H. pylori infection and IBS (OR 1.20; 95% CI 0.63-2.29; p = 0.57; I² = 63.4%). A single case-control study evaluating inflammatory bowel disease (IBD) demonstrated an inverse association with ulcerative colitis, which is presented narratively due to insufficient studies for meta-analysis. In this restricted analysis, no significant association between H. pylori infection and IBS was observed. These findings should be interpreted cautiously, given the limited number of studies and reliance on unadjusted estimates.