Increased risk of colorectal adenoma and benign colorectal polyp associated with Helicobacter pylori infection: a systematic review and meta-analysis.

Background: Although the association between Helicobacter pylori (H. pylori) infection and the risk of colorectal adenomas (CRAs) is suggested, specific analysis of the histological subtype of CRA is limited. The aim of the study was to conduct a meta-analysis on the risk of histological classifications of CRA as benign colorectal polyp (BCP), CRA, and advanced CRA to investigate the effects of H. pylori.

Methods: A comprehensive literature searches of the PubMed, Embase, and Cochrane databases through January 2024. Meta-regression analysis was conducted to identify potential moderators (e.g., histological subtype and ethnic groups).

Results: Among the 503,365 participants across 40 studies, H. pylori was consistently associated with increased probabilities of BCP, CRA, and advanced CRA. In BCP, H. pylori positive was found to be associated with an increase [odds ratio (OR), 1.430; 95% confidence interval (CI): 1.292-1.583]. In CRA and advanced CRA, H. pylori positive was found to be associated with an increase (OR, 1.711; 95% CI: 1.408-2.080). In subgroup analysis by ethnicity, Western group had lower OR compared to Asian, with a statistically significant difference observed (Western OR, 1.369; 95% CI: 1.222-1.535 vs. Asian OR, 1.990; 95% CI: 1.416-2.796, P=0.04).

Conclusions: This systematic review and meta-analysis findings revealed a significant association between H. pylori infection and BCP, CRA, and advanced CRA. In particular, meta-regression analysis confirmed that ethnicity acts as a risk factor in both BCP and CRA.