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

UNLABELLED: 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.

CONCLUSION

Current paediatric evidence does not demonstrate a significant overall association between H. pylori infection and asthma. Apparent inverse associations were confined to specific diagnostic and risk-of-bias subgroups. Evidence for celiac disease, IBD, EoE, and other immune-mediated disorders remains inconsistent. More prospective paediatric studies are needed to understand the immune modulation of H. pylori infection.

WHAT IS KNOWN: • The relationship between Helicobacter pylori infection and allergic or immune-mediated diseases remains complex and incompletely understood. • Previous studies, including mixed studies with adult and paediatric populations, have reported inconsistent and sometimes conflicting associations.

WHAT IS NEW: • This is the first comprehensive paediatric review covering multiple conditions simultaneously, synthesising evidence on the association between Helicobacter pylori infection and allergic and immune-mediated diseases. • Analysis of paediatric data found no overall association between H. pylori infection and asthma risk. Histology-based studies confirmed this finding, whereas a slight inverse association was observed only in studies using non-invasive diagnostic methods (UBT or SAT) and in those with a higher risk of bias.