A mother mouse’s gut microbes help wire her pup’s brain

New findings in mice suggest yet another role for gut microbes, even before birth.

The microbes residing in a female mouse’s gut help shape the wiring of her offspring’s brain, researchers report September 23 in Nature. While mouse and human development are worlds apart, the study hints at how a mother’s microbiome may have long-term consequences for her offspring.

Scientists have previously found links between a mouse mother’s microbiome and her young’s brain and behavior, but many of those studies worked with animals that were stressed (SN: 7/9/18) or sick. Instead, Helen Vuong, a neurobiologist at UCLA, and her colleagues looked at what a mother’s microbial mix normally does for her pups’ brains.

The new results point to the influence of specific microbes and the small molecules they produce, called metabolites. “Metabolites from the microbiome of the mother can influence the developing brain of the fetus,” says Cathryn Nagler, an immunologist at the University of Chicago who was not involved with the study. The metabolites do this by reaching a developing pup’s brain where they affect the growth of axons, she says. Axons are the threadlike signal-transmitters of nerve cells.