Antibiotics in childhood linked to obesity

Taking antibiotics in infancy has been linked to a higher risk of obesity, a study suggests.

Researchers said the drugs may alter gut bacteria, making a child more susceptible to weight gain.

Antacids – drugs taken to curb excessive stomach acid – taken in the first two years of life may also have an effect, though much smaller, researchers from the US found.

The study, published in the journal Gut, found the effect was more pronounced among youngsters who used the drugs for a prolonged period.

Alterations in gut bacteria have been linked with obesity, and early exposure to medications can alter the bacteria.

The researchers set out to assess the use of antibiotics as well as histamine-2 receptor antagonist (H2RA) and proton pump inhibitor (PPI) antacid prescriptions during early childhood among those with a diagnosis of obesity.

They examined data on more than 333,000 infants whose medical records had been input into the US Military Health System database between 2006 and 2013.

The research focused on medicines prescribed to these youngsters during the first two years of their lives.

Almost three-quarters (72.4%) had been prescribed an antibiotic, while 39,488 (11.8%) had been prescribed an H2RA and 11,089 (3.3%) a PPI.

During the follow-up, 46,993 (14.1%) children became obese, of whom 9,628 had not been prescribed any antibiotics or acid suppressants.

Boys, those born after a Caesarean section, and those whose parents were below officer rank were more likely to become obese.

Researchers also calculated that youngsters were 26% more likely to be diagnosed with childhood obesity if they had been prescribed an antibiotic.

Acid suppressants were also associated with a heightened obesity risk, although to much a lesser extent.

Because the study is observational it cannot establish cause but the authors wrote: “We found that outpatient prescriptions for antibiotics and acid-suppressing medications within the first
two years of life are associated with the development of early childhood obesity.

“This association became stronger with prescriptions for more than one type of microbiota-altering medication.”

Dr Max Davie, officer for health promotion for the Royal College of Paediatrics and Child Health, said: “Although this is reported as the largest study of its kind, it has got its limitations – it is observational and so you can’t establish cause, information about the mother’s weight, whether they smoked or had other underlying conditions aren’t available and there are complex links between the environment and obesity that need to be taken into account.

“That said, childhood obesity levels in the UK are at crisis point with one in three children overweight or obese by the time they leave primary school.

“We are also battling antibiotic resistance so any avoidable doses throughout the life-course would be beneficial to the cause.

“We therefore need to acknowledge these findings and would welcome further review. In the meantime, children who are obese must receive tailored support to help them return to a healthy weight – we therefore call on the Government to ensure specialist obesity services are appropriately funded to prevent obese children today becoming obese adults in future.”