Children who are given antibiotics or antacids in their first 2 years of life are more likely to become obese during their childhood, according to a new study published today in the British Medical Journal, Gut.

The study, “Antibiotic and Acid Suppression Medications during Early Childhood are Associated with Obesity,” was conducted by the Uniformed Services University of the Health Sciences (USU) in collaboration with Walter Reed National Military Medical Center (WRNMMC). The researchers, led by Air Force Lt. Col. (Dr.) Cade Nylund, an associate professor of pediatrics at USU, sought to identify modifiable risk factors that could help combat the nation’s obesity epidemic. Based on previous studies, they knew several commonly prescribed pediatric medications, like antibiotics and acid suppressants, can alter the development of the human microbiome, an internal ecosystem made up of bacteria that benefits the immune system. In addition to the adverse health effects of pediatric obesity, it also has a growing impact on military readiness. Eighty percent of potential military recruits are now rejected for enlistment, with obesity cited as the number one reason.

The researchers analyzed health-care records for 333,353 children in the Military Health System who were born between October 2006 and September 2013. About 241,500 of those children (72.4%) had been prescribed an antibiotic, and just more than 39,400 (11.8%) were prescribed an acid suppressant before age 2. They followed infants from the time they were initially exposed to these medication for as long as 8 years and found there was an association between antibiotic prescriptions and obesity. This association persisted regardless of which class of antibiotics was prescribed, and strengthened with each additional class of antibiotic that was prescribed. Antacids—including those used to control excess stomach acid as well as acid reflux—were also associated with obesity, with a stronger association for each 30-day supply prescribed. The link to obesity also grew commensurately with exposure to each additional medication group prescribed.

The interaction between gut bacteria, obesity, and these medications is complex, and the association could be influenced by several other factors, such as diet, Nylund said. However, the researchers believe these medications could increase gastric pH, which disrupts the native gastrointestinal microecosystem—how the body naturally digests and absorbs nutrients, and this may have an influence on weight gain.

He explained that while parents should not avoid antibiotics or acid medications when necessary, fevers in infants are often viral and not treated effectively with antibiotics. Infants spitting up is also normal and, in most circumstances, they do not need acid-suppressing medications, he added. Most infants grow out of acid reflux by 12-18 months old. When infant reflux is a concern, it could often be addressed by changing the mother’s diet when breast-feeding, by switching formula type, or if the baby is growing well and isn’t in discomfort, simply waiting to grow out of it.

“The role of the pediatrician in addressing the obesity epidemic is critical, and prevention is key,” Nylund said. He hopes these findings will stimulate a critical review of unnecessary prescriptions in infants, ultimately making an impact on the obesity epidemic.

—Newswise