In Reply As Dr Esposito points out, growth trajectories did not differ between children exposed vs unexposed to antibiotics in the first 6 months of life in our study. This primary exposure window was developed a priori based on the biological mechanism through which antibiotics have been shown to influence adiposity in animal models. However, because of previous reports cited by Esposito1,2 (and others), we also examined a secondary antibiotic exposure window (24 months) and found a statistically significant but, in our opinion, clinically meaningless increase in growth—approximately 150 g over 3 years, the equivalent of a small cup of water. Even if the finding of this secondary analysis were real, there is no evidence that 150 g of weight has any untoward health effects for any one individual and thus should not be considered a larger public health threat for the population of children exposed to antibiotics. Furthermore, no increase in growth was found in the preplanned study of twins discordant for antibiotic exposure at 24 months, and subanalyses revealed no clinically meaningful differences between antibiotic spectrum (antianaerobic or macrolides) or exposure dose response (1, 2, or ≥3 courses).
Gerber JS, Bryan M, Stallings VA. Early Antibiotic Exposure and Childhood Weight Gain—Reply. JAMA. 2016;316(5):542. doi:10.1001/jama.2016.7309