Although scientists know that autistic individuals exhibit gastrointestinal symptoms including inflammation and other intestinal abnormalities, they haven't been able to pinpoint what causes those symptoms. Until now.

New research from the Mailman School of Public Health at Columbia University, to be published in the online journal mBio®, has shown that autistic children harbor a type of bacteria in their guts that non-autistic children do not.

Sutterella bacteria was found in 12 of 23 tissue samples from the guts of autistic children, organisms that weren't present in any samples from non-autistic children.

"Most work that has been done linking the gut microbiome with autism has been done with stool samples," says Jorge Benach, Chairman of the Department of Microbiology at Stony Brook University. "What may show up in a stool sample may be different from what is directly attached to the tissue."

Tissue biopsy samples are harder to come by, as they require surgery.

It remains to be seen how this particular form of bacteria impacts development, yet it is an exciting lead in what remains a largely mysterious disorder.