Association between Helicobacter pylori infection and irritable bowel syndrome: a systematic review and meta-analysis.

BACKGROUND: Helicobacter pylori infection and irritable bowel syndrome (IBS) negatively affect the quality of life. Some previous studies found that H. pylori infection should be positively associated with the risk of IBS, but others did not. The present study aims to clarify this association, and to further analyse whether H. pylori treatment can improve IBS symptoms. MATERIALS AND METHODS: The PubMed, EMBASE, Cochrane library, Chinese National Knowledge Infrastructure, China Science and Technology Journal and Wanfang databases were searched. Meta-analysis was performed using a random-effect model. The pooled odds ratios (ORs)/risk ratios (RRs) and their 95% CIs were calculated. Heterogeneity was evaluated using the Cochran's Q test and I2 statistics. Meta-regression analysis was used to explore the sources of heterogeneity. RESULTS: Thirty-one studies with 21 867 individuals were included. Meta-analysis of 27 studies found that patients with IBS had a significantly higher risk of H. pylori infection than those without (OR = 1.68, 95% CI 1.29 to 2.18; p < 0.001). The heterogeneity was statistically significant (I² = 85%; p < 0.001). Meta-regression analyses indicated that study design and diagnostic criteria of IBS might be the potential sources of heterogeneity. Meta-analysis of eight studies demonstrated that H. pylori eradication treatment had a higher improvement rate of IBS symptoms (RR = 1.24, 95% CI 1.10 to 1.39; p < 0.001). The heterogeneity was not significant (I² = 32%; p = 0.170). Meta-analysis of four studies also demonstrated that successful H. pylori eradication had a higher improvement rate of IBS symptoms (RR = 1.25, 95% CI 1.01 to 1.53; p = 0.040). The heterogeneity was not significant (I² = 1%; p = 0.390). CONCLUSION: H. pylori infection is associated with an increased risk of IBS. H. pylori eradication treatment can improve IBS symptoms.