Breast-feeding and Helicobacter pylori infection: systematic review and meta-analysis

Objective To quantify the association between breast-feeding and Helicobacter pylori infection, among children and adolescents. Design We searched MEDLINETM and Scopus(TM) up to January 2013. Summary relative risk estimates (RR) and 95 % confidence intervals were computed through the DerSimonian and Laird method. Heterogeneity was quantified using the I-2 statistic. Setting Twenty-seven countries/regions; four low-income, thirteen middle-income and ten high-income countries/regions. Subjects Studies involving samples of children and adolescents, aged 0 to 19 years. Results We identified thirty-eight eligible studies, which is nearly twice the number included in a previous meta-analysis on this topic. Fifteen studies compared ever v. never breast-fed subjects; the summary RR was 087 (95 % CI 057, 132; I-2=344 %) in middle-income and 085 (95 % CI 054, 134; I-2=791 %) in high-income settings. The effect of breast-feeding for 4-6 months was assessed in ten studies from middle-income (summary RR=066; 95 % CI 044, 098; I-2=657 %) and two from high-income countries (summary RR=156; 95 % CI 057, 426; I-2=683 %). Two studies assessed the effect of exclusive breast-feeding until 6 months (OR=091; 95 % CI 061, 134 and OR=171; 95 % CI 066, 447, respectively). Conclusions Our results suggest a protective effect of breast-feeding in economically less developed settings. However, further research is needed, with a finer assessment of the exposure to breast-feeding and careful control for confounding, before definite conclusions can be reached.