Recent research is revealing that the gut influences more than digestion — it affects immunity, stress response, and even mental health. Scientists are now exploring whether a mother’s gut microbiome during pregnancy could impact her child’s neurological development, including potential links to autism.
A new study from the University of Virginia School of Medicine, published in The Journal of Immunology, focuses on interleukin-17a (IL-17a), an immune system protein previously linked to inflammatory conditions like psoriasis and multiple sclerosis. Researchers examined how gut bacteria that trigger IL-17a during pregnancy could affect offspring brain development.
Autism spectrum disorder (ASD) is a developmental condition affecting communication, social interaction, and behavior. Its causes are complex, involving genetic, environmental, and biological factors. According to Dr. John Lukens, the study’s lead researcher, the maternal microbiome may play a critical role. “The microbiome can shape the developing brain in multiple ways,” Lukens explained. “It’s vital for calibrating how the offspring’s immune system responds to infection, injury, and stress.”
In the study, mice were divided into two groups: one with gut bacteria known to trigger IL-17a, and a control group without. When IL-17a activity was suppressed during pregnancy, offspring from both groups developed normally. But when IL-17a acted naturally, the first group’s offspring displayed behaviors resembling autism, including repetitive actions, reduced social engagement, and unusual communication patterns.
To test whether gut bacteria were responsible, the researchers performed fecal transplants from the first group to the control mice. Soon after, even the control offspring began showing similar autism-like behaviors, suggesting a causal link between maternal gut bacteria, immune response, and brain development.
“This indicates the mother’s microbiome, not the child’s, may have a greater influence on autism risk,” Lukens said.
