Researchers look at the link between gut bacteria and autism

New research looks to the gut microbiome to try to address some of the symptoms associated with autism, but this investigation comes with its own set of problems.

The National Institute of Neurological Disorders and Stroke explain that "autism spectrum disorder (ASD) refers to a group of complex neurodevelopment disorders characterized by repetitive and characteristic patterns of behavior and difficulties with social communication and interaction." They also point out that specialists use the term "spectrum," as autism is different in different individuals. The condition can incorporate a "wide range of symptoms, skills, and levels of disability in functioning."

Research has also found that autistic children often experience chronic gastrointestinal problems a lot more frequently than children without autism. This has led scientists from Arizona State University in Tempe to explore whether a fairly new form of therapy — microbiota transfer therapy (MTT) — can help solve gastrointestinal issues in autistic children. Also, they wanted to see whether this intervention could affect other autism markers. MTT involves collecting, processing, and freezing the fecal material of healthy people, and then administering it — orally or rectally — to the person receiving the treatment. Thus, the healthy bacteria should re-establish a balance in the gut microbiome of the person experiencing gastrointestinal problems.

The researchers explain that at the start of the study, autistic children had poorer bacterial diversity in the gut, compared with neurotypical children with healthy and balanced microbiota. More specifically, two beneficial bacterial strands — Bifidobacteria and Prevotella — were lacking in the microbiota of children on the spectrum. Following the initial MTT intervention, the autistic children experienced more gut bacterial diversity, including increased levels of Bifidobacteria and Prevotella. In the new clinical trial, which measured bacterial diversity in the gut after 2 years from the intervention, the children had even more bacterial diversity and a steady presence of healthful bacteria.

Special Diets, Supplements Not Always Helpful for Kids with Autism

Many children with an autism spectrum disorder (ASD) are picky eaters, and parents may direct them to nutritional supplements, or gluten- or casein-free diets.

However, the study reported June 4 in the Journal of the Academy of Nutrition and dietetics found that these regimens leave children still deficient in some nutrients, such as calcium. On the other hand, special diets and supplements can cause children to take in excessive amounts of other nutrients, such as vitamin A, the researchers said.

“Each patient needs to be individually assessed for potential nutritional deficiencies or excess,” study lead researcher Patricia Stewart, assistant professor of pediatrics at the University of Rochester medical Center in Rochester, N.Y., said in a journal news release.

“Children with an autism spectrum disorder are not very different nutritionally form non-ASD children,” said Dr. Andrew Adesman, chief of developmental and behavioral pediatrics at the Cohen Children’s Medical Center of New York, in New Hyde Park, N.Y.

“Giving children with an autism spectrum disorder a multivitamin/mineral supplement will not correct many of the nutritional deficiencies seen in these children,” he added, “and may in fact lead to excess amounts of some nutrients in the blood stream.”