Macrolides Affect Toddler Gut Development

Normal gut microbiota development is disrupted with early life antibiotic use, according to findings published in Nature Communications.

Researchers from the University of Helsinki studied 142 Finnish schoolchildren from two to seven years at two separate time periods to understand the impact of early life antibiotics on their developing microbiomes.

The researchers commented that mouse studies indicated a causal role in the disrupted development of the gut microbe. They observed how many courses of antibiotics the children received in their lifetimes as well as how the use of antibiotics was reflected in their intestinal microbiota. The researchers also examined what the link was between antibiotics use, asthma, and body mass index.

The researchers noted that there was clear evidence of antibiotics use in the children’s gut microbes. The use of antibiotics reduced the variety of gut bacterial species and slowed the development of microbiota. The researchers noted that children treated with macrolide antibiotics like azithromycin or clarithromycin differed from the normal if the treatment occurred in the previous two years. The shorter amounts of time that had passed since the antibacterial treatment, the longer the differences were present in the microbiota, the researchers explained.

“In general, it seems that the gut microbiota recovery from antibiotic treatment lasts more than a year,” researcher Katri Korpela explained in a press release. “If a child gets repeated courses of antibiotics during their first years, the microbiota may not have time to fully recover.”

Features of the microbiota noted that implications of obesity and metabolic diseases were also found in the children treated with macrolide antibiotics. Using macrolides in the first two years of the child’s life was linked to an increased body mass index, the researchers said. In addition, heavy macrolides use in the first two years of the child’s life also was linked to asthma later in life.

The researchers added that the children who had been treated with macrolides seemed to have developed a resistance to antibiotics.

“Penicillin type antibiotics seemed to have a weaker impact on the composition and functioning of the microbiome than macrolides,” added Korpela, whose doctoral thesis is centered on the findings.

The researchers believe that macrolides should be avoided as the primary antibiotic, and should be restricted to actual need. The researchers concluded that antibiotics should not be used to treat self-limiting infections and should never be used “just in case.”