Antibiotics are medicines that are usually used in the treatment and prevention of bacterial infection. A new study has revealed that multiple courses of commonly used antibiotics may have a significant impact on children's development. The study findings suggest that female mice treated with two classes of widely used childhood antibiotics gained more weight and developed larger bones than untreated mice. However, at the same time both the antibiotics were also found to disrupt the gut microbiome, the trillions of microbes that inhabit the intestinal tract.
During the study, the mice were given three short courses of amoxicillin (a broad-spectrum antibiotic), tylosin or a mixture of both drugs. Lead co-author Laura M. Cox from the department of medicine at NYU School of Medicine said, "The number of courses of antibiotics matters. We get a little interruption of the maturation process after the second course of antibiotics, and then we have even more interruption after three courses."
Short, high-dose pulses of tylosin were found to have the most pronounced and long-lasting effect on weight gain, while amoxicillin had the biggest effect on bone growth, a prerequisite for increased height. These drugs altered not only the bacterial species, but also the relative numbers of microbial genes linked to specific metabolic functions.
The study authors said, "Antibiotic-exposed microbiomes may be less adaptable to environmental changes. The more pronounced effects of tylosin on weight gain and microbiome disruption are especially worrisome, given the increasing popularity of macrolide antibiotic prescriptions for children. The accumulating evidence highlights the need for better awareness of the potential downsides of antibiotic overuse."
The study was published online in Nature Communications.