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Study: Autism Symptoms Nearly Cut in Half 2 Years After Fecal Transplant

Study: Autism Symptoms Nearly Cut in Half 2 Years After Fecal Transplant

A new study demonstrates how children with autism spectrum disorder (ASD) experience long-term improvements in gut health and autism symptoms after undergoing a new fecal transplant technique known as Microbiota Transfer Therapy (MTT).

MTT improves gastrointestinal (GI) distress by introducing key strains of beneficial bacteria and helping to raise levels of biodiversity within the gut, boosting health overall.

At the start of the study, 83 percent of participants were rated as having severe autism. At the end of the study, only 17 percent were severe; 39 percent were mild/moderate; and 44 percent were below the cut-off for mild ASD.

In addition, at two years post-treatment, most of the initial improvements in gut symptoms remained. Parents reported a slow steady reduction of ASD symptoms during treatment and throughout the following two years. A professional evaluator also found a 45 percent reduction in core ASD symptoms (language, social interaction and behavior) at two years post-treatment compared to before treatment began.

The study, led by researchers at Arizona State University (ASU), is published in the journal Scientific Reports.

A growing body of research shows the importance of the gut microbiome, the collection of microbes that lives in our intestines and helps us in many ways including digestion of our food, training our immune system and preventing overgrowth of harmful bacteria.

Recent studies have shown that the gut microbiome may also affect brain communication and neurological health. In fact, new evidence suggests that changes in normal gut microbiota may be responsible for triggering a vast range of diseases.

“We are finding a very strong connection between the microbes that live in our intestines and signals that travel to the brain,” said Rosa Krajmalnik-Brown, Ph.D., a professor at the Biodesign Swette Center for Environmental Biotechnology at the Biodesign Institute and ASU’s School for Sustainable Engineering and the Built Environment. “Two years later, the children are doing even better, which is amazing.”

“Many kids with autism have gastrointestinal problems, and some studies, including ours, have found that those children also have worse autism-related symptoms,” said Krajmalnik-Brown. “In many cases, when you are able to treat those gastrointestinal problems, their behavior improves.”

Around 30-50 percent of all individuals with autism have chronic GI problems, primarily constipation and/or diarrhea that can last for many years. That chronic discomfort and pain can cause irritability, decreased attention and learning, and negatively impact behavior.

In the new study, the researchers have shown that by transferring healthy microbiota to individuals lacking certain gut bacteria, it is possible to “donate” a more diverse set of bacteria into the patient and improve gut health.

The fecal transplant technique was originally pioneered by Dr. Thomas Borody, an Australian gastroenterologist.

The researchers compared differences in the microbiome of children with autism compared to typically developing children. At the start of the study, children with autism were found to have lower diversity in their respective gut microbes and were depleted of certain strains of helpful bacteria, such as Bifidobacteria and Prevotella.

“Kids with autism are lacking important beneficial bacteria, and have fewer options in the bacterial menu of important functions that bacteria provide to the gut than typically developing kids,” Krajmalnik-Brown said.

The work done at ASU is not only about treating patients but also about learning from the treatment in order to develop better formulations and optimize dosing.

“Understanding which microbes and chemicals produced by the microbes are driving these behavioral changes is at the heart of our work,” Krajmalnik-Brown said.

The study showed that two years after treatment stopped the participants still had an average of a 58 percent reduction in GI symptoms compared to baseline. In addition, the parents of most participants reported “a slow but steady improvement in core ASD symptoms.”

“Every family completed the study, and every family returned two years later for a follow-up evaluation,” said James Adams, Ph.D, citing the families’ dedication to the research. “The treatment was generally well-tolerated with minimal adverse effects.”

All of the participants in the study exhibited chronic GI symptoms from infancy, including chronic constipation and/or chronic diarrhea. The treatment benefits extended beyond their physical symptoms, even causing some parents to note how much their children’s behavior had improved over time.

Many of the participants in the trial shared common traits, including birth by C-section, reduced breastfeeding, increased antibiotics, and low fiber intake by the mother and child, all of which lead to limited biodiversity in their gut bacteria.

Due to the open label nature of the study and the small sample size used, more studies are needed in order to confirm the usefulness of MTT as a therapeutic.

Source: Arizona State University

Study: Autism Symptoms Nearly Cut in Half 2 Years After Fecal Transplant

Traci Pedersen

Traci Pedersen is a professional writer with over a decade of experience. Her work consists of writing for both print and online publishers in a variety of genres including science chapter books, college and career articles, and elementary school curriculum.

APA Reference
Pedersen, T. (2019). Study: Autism Symptoms Nearly Cut in Half 2 Years After Fecal Transplant. Psych Central. Retrieved on September 28, 2020, from
Scientifically Reviewed
Last updated: 10 Apr 2019 (Originally: 10 Apr 2019)
Last reviewed: By a member of our scientific advisory board on 10 Apr 2019
Published on Psych All rights reserved.