The Association Between Helicobacter pylori Infection and Eosinophilic Esophagitis: Systematic Review and Meta‐Analysis

BACKGROUND: Exposure to Helicobacter pylori (H. pylori) has been associated with reduced odds of eosinophilic esophagitis (EoE). AIMS: To conduct a systematic review and meta-analysis of epidemiological studies in order to quantify the association between H. pylori infection and EoE, and to assess the certainty of the evidence linking both conditions. METHODS: A comprehensive literature search was conducted in MEDLINE/PUBMED, EMBASE, and SCOPUS databases (up to September 2024) to identify observational epidemiological studies that assessed the association between objectively measured H. pylori infection and EoE. The risk of study bias was assessed structurally using the ROBINS-E tool. Data were pooled using a random-effects meta-analysis. The certainty of the evidence was assessed using the GRADE approach. RESULTS: 50%) [low-certainty evidence]. The protective effect of H. pylori was stronger in case-control studies (OR 0.49; 95% CI, 0.35-0.69) than in cohort studies (OR 0.76; 95% CI, 0.58-0.98) and was statistically significant in retrospective studies (OR 0.57; 95% CI, 0.45-0.72) and studies with high or very high risk of bias (OR 0.52; 95% CI, 0.42-0.64), but not in prospective studies (OR 0.56; 95% CI, 0.27-1.18) or those with moderate to low risk of bias (OR, 0.91; 95% CI, 0.69-1.21). CONCLUSIONS: The association between H. pylori and EoE is mainly supported by retrospective studies with a high risk of bias. Further well-designed studies are needed. TRIAL REGISTRATION: PROSPERO number: CRD42024586653.