Atopy and Helicobacter Pylori (H, Pylori) infection: A systematic review and Meta-analysis

INTRODUCTION: The extent to which H pylori infection reduced the risk of  atopy is still inconclusive.This review aimed to  synthesize evidence from studies that evaluated the association between atopy and H pylori infection. 

METHODS:  A comprehensive literature search in MEDLINE/PUBMED and , EMBASE ( up to August 2013) and published in English language was done to identify observational  epidemiological studies (cross-sectional, cohort, case–control) that evaluated the association between  atopy and H pylori infection. Study quality of included studies was assessed by the Newcastle-Ottawa scale. Random-effects meta-analyses were used for pooled analysis

RESULTS: Twenty-three observational studies involving 22,716 participants were identified. Of these ,only 17 met our inclusion criteria for quantitative analysis.  Compared  H pylori negative , the overall combined odds ratios (ORs) for developing atopy were 0.82 (95% CI 0.74–0.91; P < 0.01) for H pylori infected, the odds of developing atopy was 18% lower in H pylori infected than non infected. There was no evidence of heterogeneity in estimated effect size between the studies  (Heterogeneity chi-squared =  12.29 (d.f.=16) p = 0.724 and  I²= 0.0%,) using random effects model.      

CONCLUSIONS:  Evidence from epidemiological studies suggests that, H pylori infection is inversely associated with the risk of developing atopy.