Most research into autism spectrum disorders has focused on genetic, behavioral and neurological aspects of the illness, but people with autism also show striking alterations in immune status.

What’s more, a significant subset of children with autism spectrum disorders show chronic intestinal abnormalities, such as loose stool and altered bacterial microbiota (the collection of beneficial bacteria within the intestine). Antibacterial treatments are reported to provide behavioral improvements in some cases.

In addition, many children with autism have been diagnosed with food allergies and are on special diets. Societal advances (including ‘Western’ diets and antibacterial products) may have paradoxically compromised human health by reducing our exposure to health-promoting gut bacteria.

The connection between gut bacteria, intestinal disease and autism is a promising area of investigation. Sarkis Mazmanian and his team at the California Institute of Technology used mouse models that show autism-like features to evaluate the efficacy of probiotics.

They found that specific probiotic bacteria ameliorate autism-like behaviors in both environmental models of ‘induced’ disease (by mimicking viral infection of the mother during gestation), as well is in two genetic models of autism spectrum disorder.

These studies are an important step in furthering research that addresses the connection between the gut microbiome and altered behaviors, a link suggested by studies in humans. Finally, Mazmanian’s findings may help validate the use of probiotics as a safe and effective treatment for autism when it is accompanied by gastrointestinal abnormalities.