Original StudieS

Background: Antibiotic treatment of childhood illnesses is common in India. In addition to contributing to antimicrobial resistance, antibiotics might result in increased susceptibility to diarrhea through interactions with the gastrointes-tinal microbiota. Breast milk, which enriches the microbiota early in life, may increase the resilience of the microbiota against perturbations by antibiotics. Methods: In a prospective observational cohort study, we assessed whether antibiotic exposures from birth to 6 months affected rates of diarrhea up to age 3 years among 465 children from Vellore, India. Adjusting for treatment indicators, we modeled diarrheal rates among children exposed and unex-posed to antibiotics using negative binomial regression. We further assessed whether the effect of antibiotics on diarrheal rates was modified by exclu-sive breastfeeding at 6 months. Results: More than half of the children (n = 267, 57.4%) were given at least one course of antibiotics in the first 6 months of life. The adjusted relative incidence rate of diarrhea was 33 % higher among children who received antibiotics under 6 months of age compared with those who did not (inci-dence rate ratio: 1.33, 95 % confidence interval: 1.12, 1.57). Children who were exclusively breastfed until 6 months of age did not have increased diarrheal rates following antibiotic use. Conclusions: Antibiotic exposures early in life were associated with increased rates of diarrhea in early childhood. Exclusive breastfeeding might protect against this negative impact