Paediatric Helicobacter pylori infection and allergic and inflammatory diseases: a contemporary systematic review with meta-analysis

Helicobacter pylori (H. pylori) infection is prevalent worldwide, and its potential protective role in allergic and immune diseases has been a topic of speculation. This systematic review aims to analyse recent literature to establish a consensus on this relationship. Articles published in the past 12 years regarding association of H. pylori and various allergic diseases were screened. Thirty-five articles from three databases were assessed for bias using the ROBINS-E tool. Objective data from each article were collected for this review. Among the reviewed articles, 14 focused on asthma, 10 on eliac disease(CeD), 5 on eosinophilic esophagitis (EoE), 7 on inflammatory bowel disease (IBD), and 8 on mixed conditions. In the asthma meta-analysis, H. pylori infection was not significantly associated with asthma overall (OR 0.75, 95% CI 0.54-1.05; I2 = 67.3%). Subgroup analyses showed an inverse association in studies using UBT/SAT, whereas histology-based studies showed no association. Low-risk-of-bias studies likewise showed no significant association. Results for celiac and IBD were mixed. No clear trends were observed for the other conditions analysed.