The study was published in Nature Communications and was funded by the United States Office of Naval Research.
“In this paper, we report that low-dose penicillin taken late in pregnancy and in early life of mice offspring, changes behavior and the balance of microbes in the gut. While these studies have been performed in mice, they point to popular increasing concerns about the long-term effects of antibiotics,” says Dr. John Bienenstock, Director of the Brain-Body Institute at St. Joseph’s Healthcare Hamilton and Distinguished Professor at McMaster University. “Furthermore, our results suggest that a probiotic might be effective in preventing the detrimental effects of the penicillin.”
Other studies have shown that large doses of broad-spectrum antibiotics in adult animals can affect behavior. But there haven’t been previous studies that have tested the effects of clinical doses of a commonly-used, narrow-spectrum antibiotic such as penicillin on gut bacteria and behavior.
“There are almost no babies in North America that haven’t received a course of antibiotics in their first year of life,” says Dr. Bienenstock. “Antibiotics aren’t only prescribed, but they’re also found in meat and dairy products. If mothers are passing along the effects of these drugs to their as yet unborn children or
children after birth, this raises further questions about the long-term effects of our society’s consumption of antibiotics.”
A previous study in 2014 raised similar concerns after finding that giving clinical doses of penicillin to mice in late pregnancy and early life led to a state of vulnerability to dietary induction of obesity.
Sophie Leclercq, Firoz M. Mian, Andrew M. Stanisz, Laure B. Bindels, Emmanuel Cambier, Hila Ben-Amram, Omry Koren, Paul Forsythe, John Bienenstock. Low-dose penicillin in early life induces long-term changes in murine gut microbiota, brain cytokines and behavior. Nature Communications, 2017; 8: 15062 DOI: 10.1038/ncomms15062