Children who receive antibiotics throughout their early lives gain weight significantly faster than those who don't, according to a Johns Hopkins Bloomberg School of Public Health study.
The bacteria that are killed off by antibiotics are likely those that contribute to digestion and nutrient absorption in the gastrointestinal tract, the researchers said.
"Your BMI may be forever altered by the antibiotics you take as a child," Brian S. Schwartz, MD, a professor in the Department of Environmental Health Sciences at the Bloomberg School and lead author of the study, said in a statement. "Our data suggest that every time we give an antibiotic to kids they gain weight faster over time."
A review of the EHRs of more than 163,000 children between three and 18 years old revealed that by age 15, those who had taken antibiotics seven or more times weighed about three pounds more than those who had received no antibiotics. The authors claim that three pounds is likely an underestimate because the children did not necessarily stay within the same health system throughout their childhoods and the records may not be complete.
"While the magnitude of the weight increase attributable to antibiotics may be modest by the end of childhood," Dr. Schwartz said. "Our finding that the effects are cumulative raises the possibility that these effects continue and are compounded into adulthood."
Antibiotics have long been used to fatten livestock and while prior studies have suggested that they make have the same effect on small children, the Johns Hopkins research demonstrates their use can have that effect at any age.
They conclude that systematic or broad-spectrum antibiotics should be avoided expect when absolutely necessary.