“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.”
What holds the clue between microbiome and autism might be a molecule produced by the immune system called interleukin-17a, or IL-17a.
Scientists performed the research on mice with different gut microbiota. While one group had bacteria linked to a stronger inflammatory response triggered by IL-17a, the control group did not.
When they supressed IL-17a artificially at the pups, both groups displayed neurotypical behavior, but later on, when the human interference stopped and the mice grew naturally, those of the first group showed symptoms typical of autism, such as repetitive behavior.
Afterwords, researchers used the feces of the mice in the first group to perform a fecal transplant on the mice in the second group to effectively transfer the pro-inflammatory gut bacteria. As suspected, the mice from the second group also developed autism-like behavior.
