Antibiotics unlikely to cause childhood obesity

A major new study has found that antibiotics use is unlikely to contribute to childhood obesity, despite previous studies suggesting a causal link.

Antibiotics change bacteria in the gut (part of the gut microbiome), and evidence from animal research suggested this could lead to obesity. However, studies checking for the same association in humans have yielded conflicting results.

The research team crunched data from nearly 290,000 New Zealand children and their mothers (151,359 children and 132,852 mothers) to look for any link between antibiotic use and childhood obesity.

The study, carried out under the Liggins Institute-hosted A Better Start National Science Challenge, was one of the largest of its kind. It drew on data from children born between July 2008 and June 2011 obtained from the B4 School Check, a national health screening programme that records height and weight of four-year-old children. This data was linked to pharmaceutical records of antibiotics dispensing.

Researchers factored in both antibiotic use by mothers before conception and during pregnancy, as well as antibiotics taken by children up to age two. Antibiotics exposure was common, with at least one course dispensed to one in three (36 percent) of mothers during pregnancy, and to four in five (82 percent) of children in the first two years of life.

While judicious prescription and use of antibiotics is vital, we concluded that antibiotics are unlikely to be a major contributor to childhood obesity.

Dr Karen Leong, lead researcher Liggins Institute

Researchers were particularly interested in trying to rule out genetic and early environmental factors shared between siblings that could be the underlying cause of any observed link, so they ran the same analyses just on siblings and twins. This revealed that antibiotic use had no bearing on the likelihood of developing childhood obesity at age four years.

“We wanted to better understand the role that antibiotics play in the development of obesity and to investigate for possible confounding factors that may have influenced these previous results,” says lead researcher, Dr Karen Leong, PhD candidate and Clinical Research Fellow at the University of Auckland-based Liggins Institute.

“While judicious prescription and use of antibiotics is vital, we concluded that antibiotics are unlikely to be a major contributor to childhood obesity,” says Dr Leong.

Professor Wayne Cutfield, Director of A Better Start National Science Challenge, was the study’s senior author.

“Although antibiotics are not associated with childhood obesity, antibiotics usage in New Zealand is extremely high, especially during early childhood, it is important to ensure proper antibiotic stewardship among healthcare professionals and the community at large,” he says.

The study was published in the JAMA Network Open. It was funded by A Better Start National Science Challenge, hosted by the Liggins Institute at the University of Auckland.

A Better Start National Science Challenge is hosted by the Liggins Institute and funded the Ministry of Business, Innovation and Employment.

Read the article:

JAMA Network Open: Associations of prenatal and childhood antibiotic exposure with obesity at age 4 years

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