How fecal transplants could help with ASD

Rosa Krajmalnik-Brown, PhD

Fecal transplants-already used in the treatment of recurrent Clostridium difficile (C diff) colitis-have been identified as a promising new treatment for autism spectrum disorder (ASD), according to a new study.

Published in Scientific Reports, the study highlights new research about the gut microbiome and its role in the pathophysiology of autism.¹ Researchers studied the link between the gut microbiome and autism-like behaviors in 18 children with ASD, treating the children with microbiota transfer therapy (MTT)-a specialized therapy involving the donation of healthy gut bacteria through fecal transplantation. The patients, aged between 7 and 17 years, also suffered from severe gastrointestinal (GI) problems since infancy, according to the report.

The researchers say the study is based on the idea that the gut and brain interact in complex ways and that abnormal gut conditions may expose patients to neurodevelopmental disorders.

Rosa Krajmalnik-Brown, PhD, associate professor at the Arizona State University Biodesign Institute, Tempe, and coauthor of the study, says research had previously indicated that low microbial diversity may play a role in ASD, with patients missing important beneficial microbes.

“Microbes produce important chemicals, some of these interact with the brain,” Krajmalnik-Brown says. “Fecal microbiota transplantation helps by adding beneficial microbes, increases diversity, changes microbial interactions, and potentially changes the quantity and quality of chemicals being produced by these microbes.”

A novel approach to treatment for ASD

Gastrointestinal comorbidities have been linked to disorders such as Parkinson’s disease and Alzheimer’s, as well as autism, the study notes. Gastrointestinal problems have been linked to children with more severe autism-related symptoms, according to the study, and research has shown that when these GI problems were treated, autism-related symptoms improved. The children involved in the study showed significant improvement in both behavior and digestive symptoms after treatment with MTT, according to the report. In fact, the study demonstrates that participants experienced a slow, steady improvement in autism-related symptoms after MTT, reducing symptoms by 45% after 2 years.

Although there are many therapies aimed at improving ASD symptoms, the research team notes that no treatments have been approved to treat core ASD symptoms such as social communication problems and repetitive behaviors. The efficacy of MMT in treating C diff infection and other GI disorders drew the attention of the research team to the possibility of MMT as a possible treatment for ASD, according to the report.

The researchers had previously performed a trial using fecal transplantation combined with antibiotics, a bowel cleanse, and mediations to control stomach acids and saw an 80% reduction in GI symptoms as well as an improvement in core ASD symptoms after 18 weeks-10 weeks of treatment and 8 weeks of observation.

In the new study, patients were reevaluated after 2 years to assess the long-term impact of MMT. The research team found that participants endorsed a 58% reduction in chronic GI symptoms and a 47% reduction in autism severity based on the Childhood Autism Rating Scale at 2 years post-treatment-an improvement over the 23% reduction 18 weeks after MMT. Parents also noted improvement: 89% of patients were rated as severe by parents on the Social Responsiveness Scale (SRS) assessment before MMT and that number dropped to 47% 2 years later. Improvements on a number of other autism-related symptoms scoring tools were noted, the researchers reported.

Overall, the research team noted that gut bacterial diversity was higher 2 years after MMT.

“Considering low gut bacterial diversity in individuals with ASD and other disorders, an increase in diversity after MTT may reflect that MTT intervention successfully transformed gut environment into a healthier status and led to a long-term benefit on GI and behavior symptoms,” the report notes.

Parents: Keep an open mind

Whereas fecal transplantation may not be at the top of the list of treatment options for some parents, Krajmalnik-Brown says it’s important to keep an open mind. “Parents of children with autism are receptive to many out-of-the-box approaches and are very hopeful that our initial success will continue and that we can treat more people,” she says.

Although fecal transplantation has not been approved by the US Food and Drug Administration as a treatment for ASD, Krajmalnik-Brown says she hopes the study findings will lead the agency to fast-track the therapy as a treatment for autism.