A new study suggests that a mother’s gut health during pregnancy may influence autism risk in her child. Researchers focused on the role of the gut microbiome and an immune molecule called IL-17a, which has been linked to inflammation.

The study, published in the Journal of Immunology and led by Dr. John Lukens at the University of Virginia, used mice to test how gut bacteria affect brain development. As the article explains, “the gut microbiome of a pregnant mother might influence the risk that her child develops autism spectrum disorder.”

Two groups of pregnant mice were studied. One carried an “inflammation-prone” microbiome that triggered IL-17a, while the other did not. Offspring of mothers with this microbiome showed autism-like behaviors, such as social difficulties and repetitive actions. Researchers wrote that “when IL-17a was suppressed, all offspring displayed neurotypical behavior.”

In another test, fecal transplants transferred gut flora from the inflammation-prone group into healthy mothers. Their pups also developed autism-like traits, strengthening the link.

Although the findings are significant, scientists caution that they are based on animal models. The article notes, “more work is needed to identify which specific microbes… are responsible” before results can be applied to humans.