Association between Helicobacter pylori and risk of childhood asthma: a meta-analysis of 18 observational studies

Objective: The association between Helicobacter pylori (H. pylori) and childhood asthma is unclear. Thus, the aim of this study was to explore the association between H. pylori and childhood asthma.Methods: A literature search, study selection, and data extraction were performed independently and in duplicate. Data were analyzed using STATA software.Results: Eighteen studies enrolling 17,196 children were analyzed. All studies were of moderate-to-high quality. Four studies subcategorized H. pylori infection according to CagA status. Overall, there was a significant negative association between H. pylori and risk for childhood asthma (OR = 0.68; 95% CI, 0.54-0.87; P = 0.002), with no/marginal publication bias identified by the Egger's test and the Begg's test (P = 0.162 and P = 0.198, respectively). The observed inverse association persisted for CagA(+) strains of H. pylori (OR = 0.58; 95% CI, 0.35-0.96; P = 0.034) but not for CagA(-) strains (OR = 0.52; 95% CI, 0.12-2.28; P = 0.387). There was no significant difference between studies with respect to study design, participant age, geographical region, and method of measuring H. pylori.Conclusion: The evidence suggests that H. pylori infection, particularly CagA(+) H. pylori infection, is inversely associated with the risk of childhood asthma. Supplemental data for this article can be accessed at publisher's website.