It's interesting you bring up the gut-brain connection. Research shows that children with autism often have different gut bacteria compared to neurotypical children. They may have less of the good bacteria, like Bifidobacterium, and more Clostridium species.

This can lead to gut issues like constipation or abdominal pain, which can then impact behavior. A 2021 study even found that the more severe the gut symptoms, the more frequent repetitive behaviors were in children with autism.

Also, a study from UCLA and USC discovered that children with autism had fewer neuroactive metabolites, which are important for communication between the gut and brain. It's definitely an area where more research could be helpful.