Children with autism may be helped by fecal transplants, a procedure that introduces healthy gut microbes into people with gastrointestinal disease.

Many victims of autism have gastrointestinal problems, and the study, which was published in the journal Microbiome, found that fecal transplants, which use microbes from healthy donors, eased both behavioral and gastrointestinal symptoms.

The study participants were children with autism and moderate to severe gastrointestinal problems. Both parents and doctors said the children showed positive changes that lasted at least eight weeks. The bacterial and viral gut composition of children without autism were studied before the study began.

"Transplants are working for people with other gastrointestinal problems," said researcher Ann Gregory. "With autism, gastrointestinal symptoms are often severe, so we thought this could be potentially valuable.

"Following treatment, we found a positive change in GI symptoms and neurological symptoms overall," she said.

Previous research has found connections between gut bacteria and the brain, and scientists believe there may be an important link in people with autism.

Studies have found that children with autism typically have fewer types of some important bacteria in their guts and less bacterial diversity overall. The current study also found this to be true. A possible reason could be that many of them are prescribed multiple courses of antibiotics during their first three years of life.

Parents reported improvement in gastrointestinal problems, including diarrhea and stomach pain, following treatment as well as significant improvement in behavioral symptoms of autism.

One questionnaire found the average developmental age increased by 1.4 years following treatment.

The average score on a scale for ranking gastrointestinal symptoms dropped 82 percent from the beginning to the end of treatment.

Up to 2 percent of children are believed to have some form of autism. According to the Centers for Disease Control and Prevention, the current diagnosis rate is about 1 in 68 children, a 10-fold increase from 40 years ago.

Currently, there are no drugs approved to treat autism. "The only currently approved medications are antipsychotic prescriptions that address non-core symptoms and can lead to unwanted side effects," says autism researcher John Slattery of Arkansas Children's Research Institute.