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Treating autism spectrum disorders with…feces?

People with autism spectrum disorders were treated with microbiota transfer therapy, and a follow-up study after 2 years showed improvement in autism-related symptoms.


There are millions of microbes living in our gut, called the gut microbiota. Abnormalities in gut microbiota have an impact on virtually all organs, including the brain. This brain-gut connection is of interest because many individuals suffering from neurological and developmental conditions, such as Alzheimer’s disease and Autism Spectrum Disorders, also suffer from chronic gastrointestinal symptoms. The gut microbiome is also known to be different between neurological patients and healthy people. 

Researchers from Arizona had the idea that if the gut and brain have such connection, why not try to treat the gut in order to help the brain? Changing the gut microbiome with antibiotics, probiotics, or fecal microbiota transfer could be a possible treatment option. In fecal microbiota transfer, a large number of gut microbes are transferred from a healthy person’s stool to the patient with the goal of  establishing a healthier mixture of bacteria. 

Microbial Transfer Therapy was administered to children with Autism Spectrum Disorders simultaneously suffering from chronic gastrointestinal problems. The 10 week treatment consisted of antibiotics and a bowel cleanse, followed by a high dose fecal microbiota transfer. After 8 weeks post treatment, 80% of individuals showed reduction in gastrointestinal symptoms and slow, but steady improvement in their autism-related condition.

After two years, all subjects of the study were evaluated again using a variety of gastrointestinal and behavioral tests. After measuring the patients’ gastrointestinal symptoms using Gastrointestinal Symptom Rating Scale, an average of 58% improvement was seen. This result was striking, because all of the recipients reported never having normal gastrointestinal tract functioning since infancy. Symptoms such as abdominal pain, indigestion, diarrhea, and constipation all showed improvement.

Families of the treated children have noticed slow but steady improvement in  behavior since the treatment. The Childhood Autism Rating Scale is used by professionals to diagnose and evaluate the severity of autism. Two years after the study, the researchers questioned participants again and found that the severity had dropped by 47%. At the beginning of the therapy, 83% of children participating in the study were rated as severe, but after two years post-therapy only 17% fell into that category. Shockingly, 44% of the children had fallen below the Autism Spectrum Disorder diagnostic cut-off. Additional follow-up tests further confirmed these results.   

This study shows how small things, such as microbes in our gut, can do big things to our body function, including behavior. Interaction between our body and the gut microbiome is extremely complex and not yet well understood, but it definitely has a role in health and disease. Solving this complexity will help us to  treat diseases in new ways. 

Study Information

Original study: Long-term benefit of Microbiota Transfer Therapy on autism symptoms and gut microbiota

Study was published on: 09 April 2019

Study author(s): Dae-Wook Kang, James B Adams, Devon Co, Elena L Pollard, Juan Maldonado, Sharon Mcdonough-Means, Gregory Caporaso, Rosa Krajmalnik-Brown

The study was done at: Arizona State University, Northern Arizona University

The study was funded by:

Raw data availability:

Featured image credit:

This summary was edited by: Gina Misra