Kids who receive antibiotics throughout the course of their childhood gain weight significantly faster than those who do not, a new study has warned.
The findings suggest that antibiotics may have a compounding effect throughout childhood on body mass index (BMI), a measure often used to determine whether someone is at a healthy weight.
“Your BMI may be forever altered by the antibiotics you take as a child,” said study leader Brian S. Schwartz, professor at the Johns Hopkins Bloomberg School of Public Health research.
“Our data suggest that every time we give an antibiotic to kids they gain weight faster over time,” said Schwartz.
Mr. Schwartz and colleagues analysed Geisinger Health System’s electronic health records on 163,820 children between three and 18 years old from January 2001 to February 2012.
They examined body weight and height (which are used to determine BMI) and antibiotic use in the previous year as well as any earlier years for which Geisinger had records for the children.
At age 15, children who had taken antibiotics seven or more times during childhood weighed about three pounds more than those who received no antibiotics, researchers found.
Approximately 21 per cent of the kids in the study, or almost 30,000 children, had received seven or more prescriptions during childhood.
Mr. Schwartz said that the weight gain among those frequently prescribed antibiotics is likely an underestimate since the children did not stay with Geisinger throughout childhood so their lifetime antibiotic histories.
“While the magnitude of the weight increase attributable to antibiotics may be modest by the end of childhood, our finding that the effects are cumulative raises the possibility that these effects continue and are compounded into adulthood,” he said.
Scientists working with penicillin learned early on that its byproducts caused weight gain in animals.
This led to the modern industrial farming techniques of including small quantities of antibiotics in daily animal feed to fatten up the animals in an accelerated time frame.
In humans, meanwhile, there is growing evidence that antibiotics could lead to weight gain because of the effect that they have on what is known as the microbiota, or the microorganisms that inhabit the body.
There are 10 times more bacterial cells in the human body than our own cells. Many of these bacteria do their work in the gastrointestinal tract, helping the body to digest food and absorb nutrients.
Antibiotics kill off harmful bacteria but also those vital to gastrointestinal health. Research has shown that repeated antibiotics use can forever change the microbiota, altering the way it breaks down food and increasing the calories absorbed. This, in turn, can increase weight gain.
The study was published in the International Journal of Obesity.
