Childhood obesity is a significant public health issue and research suggests the intestinal microbiome may influence body weight. This hypothesis is strengthened by a study in JAMA Pediatrics (online, 29 September 2014), in which L Charles Bailey, from the Children’s Hospital of Philadelphia, Pennsylvania, and co-authors analysed electronic health records of 64,580 children in the United States
Nearly 70% of children received antibiotics before they were two years old and one third were obese by the age of four. Exposure to four or more courses of broad-spectrum antibiotics was associated with an 11% increased risk of childhood obesity versus no exposure. No such association was seen for narrow-spectrum antibiotics.
“Narrowing antibiotic selection is potentially a modifiable risk factor for childhood obesity,” the researchers conclude.
 Bailey LC et al. Association of Antibiotics in Infancy With Early Childhood Obesity. JAMA Pediatr 2014. doi:10.1001/jamapediatrics.2014.1539 (accessed 29 September 2014).