In recent years, an increasing amount of research has been highlighting the crucial role our gut microbiome plays in our overall health. It influences everything from our reactions to fear and negative stimuli, to our weight and mental well-being, and even impacts whether we develop autoimmune conditions like lupus and type 1 diabetes.

Now, a new study published in The Journal of Immunology has uncovered a connection between the gut microbiome and autism, based on animal studies. However, researchers clarify that it’s not our own microbiome that influences whether or not we develop autism — it’s actually our mother’s.

“The microbiome can shape the developing brain in multiple ways,” John Lukens, lead researcher and PhD student from the University of Virginia School of Medicine, said in a statement.

“The microbiome is really important to the calibration of how the offspring’s immune system is going to respond to an infection or injury or stress.”

When it comes to autism, the connection may lie with a specific molecule known as interleukin-17a (or IL-17a), which is produced by the immune system. This molecule has already been linked to autoimmune conditions like rheumatoid arthritis, multiple sclerosis, and psoriasis. It’s also known for playing a key role in defending the body against infections—especially fungal ones. Interestingly, IL-17a may also affect how the brain develops before birth.