EL PASO—Early exposure to antibiotics and acid-suppressing medications is linked with the development of obesity, with an even stronger association after prolonged courses or with prescriptions for multiple antibiotic classes, according to a new military study.

The critical question is how multiple microbiota-altering medication groups affect obesity risk, according to the researchers.

“The findings offer a framework for prospective research on inpatient and outpatient medication exposures and the subsequent development of obesity in pediatric patients,” wrote study authors led by Christopher M. Stark, MD, of the William Beaumont Army Medical Center and the Walter Reed National Military Medical Center, Bethesda, MD. “The recognition of modifiable risk factors for obesity is an essential step towards reducing the incidence and burden of the disease.”

Co-authors with Stark were Apryl Susi, PhD, of the Department of Pediatrics at the Uniformed Services University of the Health Sciences in Bethesda, MD, and Jill Emerick, MD, and Cade M. Nylund, MD, both of Walter Reed and USU.

Background information in the article published in The BMJ journal Gut noted that the composition of the microbiome has been linked to various aspects of human health, including obesity. The type and volume of bacteria in the gut can be altered by certain drugs, including antibiotics and acid suppressants-histamine 2 receptor antagonists and proton pump inhibitors.1

“We hypothesized that young children exposed to microbiota-altering medications in the first two years of life are more likely to develop obesity,” the authors explained. “We used a large electronic medical record database to evaluate this association. We also sought to evaluate a potential dose effect, measured by the length of medication exposure and the effect of exposure to multiple different microbiota-altering medications on the development of obesity.”

To do that, the researchers looked at prescriptions for 333,353 infants treated by the U.S. military’s TRICARE health system from 2006-13 in the first two years of their lives.

Most, 72.5% had been prescribed an antibioticn nearly 12% an H2RA and nearly 3% a PPI during this period. All three types of the drug were prescribed to about 5,800 of the children.

Records showed that slightly more than 14% of the children became obese, with 11% of those having been prescribed no antibiotics or acid suppressants.

Results indicated that antibiotic prescriptions were associated with obesity (HR 1.26; 95% CI 1.23 to 1.28). “This association persisted, regardless of antibiotic class, and strengthened with each additional class of antibiotic prescribed,” study authors pointed out. “H2RA and PPI prescriptions were also associated with obesity, with a stronger association for each 30-day supply prescribed. The HR increased commensurately with exposure to each additional medication group prescribed.”

A prescription for antibiotics—regardless of type—was associated with a 26% heightened risk of obesity by the age of 3, the average age of which obesity was first identified in the study.

More likely to become obese were boys, those born after a caesarean section and those whose parents were below officer rank, the study team reports.

The researchers concluded, “Microbiota-altering medications administered in early childhood may influence weight gain,” adding, “There is an important therapeutic role for microbiota-altering medications. The long term risks to health must be weighed against the short-term benefits.”

1. Stark CM, Susi A, Emerick J, Nylund CM. Antibiotic and acid-suppression medications during early childhood are associated with obesity. Gut. 2018 Oct 30. pii: gutjnl-2017-314971. doi: 10.1136/gutjnl-2017-314971. [Epub ahead of print] PubMed PMID: 30377188.