A recent study in *The Journal of Immunology* highlights how gut microbiota, especially a mother’s, may influence autism development. “The microbiome can shape the developing brain in multiple ways,” said lead researcher John Lukens from the University of Virginia.The key molecule in question is interleukin-17a (IL-17a), which is involved in immune responses and has been linked to diseases like multiple sclerosis and psoriasis. Crucially, IL-17a also affects fetal brain development.

Researchers tested this by using mice from two labs: one with microbiota that triggered IL-17a-related inflammation, the other without. When IL-17a was suppressed, both groups’ offspring developed normally. Without intervention, pups from the first group later showed autism-like behavior.

To confirm the role of gut microbes, scientists transplanted feces from the first group into the second. The second group’s offspring then also developed autism-like traits, pointing to the mother’s microbiota as a driving factor.While still in early stages and not directly applicable to humans yet, the findings suggest a powerful link between maternal gut health and neurodevelopment. “IL-17a might be a single component in a much bigger picture,” Lukens noted, calling for further studies in humans.