NEW YORK, April 26 (UPI) -- Gastrointestinal problems in autistic children may be linked to the same genetic mutations that cause other characteristics of autism spectrum disorder, according to a recent study with mice.
Researchers at Columbia University Medical Center found the GI issues may relate to reduced serotonin -- which is as significant in the GI system as it is in the brain -- caused by the genetic mutations linked to some cases of ASD.
GI issues are common in children with ASD. It has been thought the issues have to do with diets limited to foods children with autism favor, though researchers found it surprising the two could be connected.
Since 95 percent of serotonin is used in the gastrointestinal system, a genetic mutation affecting how much of it is available would have a greater effect than any element of a diet, researchers say.
"Because serotonin plays an important role in the gastrointestinal system as well as the brain, we wanted to see if there was a direct relationship between these genes and GI development and function," Dr. Kara Margolis, an associate professor of pediatrics at Columbia University Medical Center, said in a press release.
For the study, published in The Journal of Clinical Investigation, researchers worked with mice that have a mutation increasing the activity of the serotonin reuptake transporter, or SERT, which prevents the substance from leaving neurons.
In previous studies, mice with a SERT mutation displayed behavior similar to children with ASD -- less vocal, repetitive in behavior and generally averse to socializing. In the new study, the researchers found fewer neurons in the gut, poorly maintained gut lining and slower movement of contents in the gut.
"Our study is one of the first to suggest that GI and neurological aspects of autism, in some cases, may stem from a shared underlying abnormality," Margolis said. "This provides scientific credibility to the idea that gastrointestinal problems may be an innate feature of autism, at least for some patients."