Early-life antibiotic use and children with overweight and obesity: a Dutch twin cohort study.

The number of children with obesity has risen over the decades, becoming a major public health concern, also because of persistence into adulthood and morbidity. Early-life antibiotic use alters gut microbiota composition, potentially causing metabolic disturbances, increasing the number of children with obesity. To explore the association between early-life antibiotic use and the risk of developing overweight/obesity during childhood, we analyzed data from the Netherlands Twin Register, using a co-twin control design in outcome-discordant pairs to control for confounding due to shared environmental and/or genetic factors. This retrospective study included data from 34,142 twins aged 4.5-15.4 years. Any antibiotic use before age 2 was reported in 24.6% of children; 1.06% were children with obesity, and 9.23% were children with overweight/obesity based on sex- and age-specific BMI thresholds from the International Obesity Task Force and the World Health Organization. We evaluated outcomes for dichotomous and continuous data (BMI Z-scores), adjusting for sex, delivery mode, gestational age, birthweight, breastfeeding, maternal BMI, and parental education levels. No association was found between early-life antibiotic use and the risk of developing obesity (OR 0.82, 95% CI 0.60-1.14) or overweight/obesity (OR 1.00, 95% CI 0.90-1.12) during childhood. Matched co-twin analyses showed similar null results. Also, BMI Z-scores did not differ by antibiotic exposure. These findings suggest that early-life antibiotic use is not associated with an increased risk of overweight or obesity in childhood.