Abstract
BACKGROUND: At present, the specific mechanism by which Helicobacter pylori (H. pylori) infection leads to gastric cancer (GC) is not clear. This study aims to systematically evaluate the correlation between H. pylori infection and the risk of GC, obesity and esophageal diseases by collecting and analyzing existing relevant studies, update the existing evidence-based medical evidence, and provide evidence to inform the etiology-based prevention and treatment of GC, obesity and esophageal diseases and further clinical research. METHODS: Literature search of the PubMed, Embase, Web of Science, Cochrane Library, ClinicalTrials.gov, CNKI, and Wanfang databases (as of June 27, 2023) was performed. Population-based studies (sample size n > 100) that reported the associations of H. pylori infection with GC, obesity, and esophageal disease and used objective methods to detect H. pylori infection were selected. Data such as effect sizes and 95% CI were extracted for analysis, and interstudy heterogeneity was analyzed on the basis of study location and certain other characteristics. RESULTS: Forty relevant studies were included, including 15, 4 and 21 studies on GC, obesity and esophageal diseases respectively. The results revealed that H. pylori infection was positively correlated with the risk of GC [OR (95% CI) = 2.68 (1.85 ~ 3.89) ; P < 0.0001], and was negatively associated with the risk of obesity [OR (95% CI) = 0.65 (0.43 ~ 0.98); P = 0.0380] and gastroesophageal reflux disease (GERD) [OR (95% CI) = 0.54 (0.43 ~ 0.68); P < 0.0001], and had no significant association with the risk of esophageal cancer (EC) [OR (95% CI) = 0.90 (0.47 ~ 1.73); P = 0.7454]. There was considerable heterogeneity among studies for some diseases, but sensitivity analysis proved that the results were stable and reliable, and no significant publication bias was found. CONCLUSION: H. pylori infection increases the risk of GC, H. pylori eradication is highly important for reducing the risk of GC. H. pylori infection was not associated with reduced risk of obesity and GERD, but the related evidence is limited and the mechanism is not clear. Based on the available evidence, decision-making for eradication treatment should follow the principle of individualization, taking into account the patient’s disease risk, strain characteristics, demographic factors, and the cost-effectiveness of treatment. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12876-025-04259-2.