The association between antibiotic use in infancy and childhood overweight or obesity: a systematic review and meta-analysis

Purpose: Antibiotic use is associated with alteration of the gut microbiome and metabolic activity. As childhood obesity is a predisposing factor for adult obesity, addressing childhood risk factors to weight gain in early life is important. This review aims to investigate the association between infant antibiotic exposure (aged < 24 months) and childhood obesity or overweight. Methods: Articles were retrieved from CINAHL, Cochrane CENTRAL, Embase and MEDLINE. Eligible articles investigated antibiotic use in exposed versus unexposed infants and measured childhood weight change. Data were synthesized narratively and meta-analysed where possible. Results: After title/abstract and full-text screening, 17 articles representing 15 unique studies were included for narrative synthesis. We found a small association between antibiotic exposure in infancy (< 24 months) and childhood overweight or obesity. The strongest associations were observed in boys versus girls and children exposed to multiple antibiotic courses or broad-spectrum drugs. Meta-analysis of 12 sets of results comparing the earliest age of exposure to any antibiotic with overweight or obesity at the latest age of outcome found a pooled odds ratio of 1.05 (95% confidence interval: 1.00-1.11). Conclusions: Antibiotic exposure in infants, aged < 24 months, was associated with a small increase in odds of childhood overweight or obesity in some subgroups of children.