Autism Speaks commits $2.3 million to research on gut-brain connection

Autism Speaks, the world's leading autism science and advocacy organization, has selected two major research projects – one focused on intestinal bacteria, the other on chronic constipation – to advance understanding of autism's gut-brain connection. Funding for the studies, each spanning three years, will total more than $2.3 million.

Research conducted through the Autism Speaks Autism Treatment Network (ATN) has demonstrated that gastrointestinal (GI) problems are very common among individuals who have autism and can worsen behavioral symptoms. In the fall of 2012, this progress was reflected in a series of guidelines on the management of autism-related medical conditions – including chronic constipation – published in the respected journal Pediatrics. Other research sponsored by Autism Speaks showed that in mice deliberate changes in the bacteria in the gut (known as "microbiome") can affect social behavior.

To follow-up on these breakthrough findings, Autism Speaks launched an initiative to fund new research on the "gut-brain" connection in autism. The most promising applicants were judged on the basis of potential impact and the soundness of their science. Proposals were reviewed by Autism Speaks science staff and a panel of scientific experts and family advisors.

"Listening to our parents, we hear how often autism and GI problems can go hand in hand." says Autism Speaks Chief Science Officer Rob Ring. "While we now know that autism and gastrointestinal problems frequently co-occur, improving our understanding of the underlying biology becomes essential for developing needed treatments."

The selected projects include an investigation led by Prof. James Versalovic, at Baylor College of Medicine, into the connection between the microbiome and autism symptoms. A second research grant will go to Prof. Pat Levitt, at Children's Hospital of Los Angeles (CHLA) and University of Southern California, for research into the treatment of chronic constipation to improve behavioral symptoms associated with autism.

Autism and the microbiome

Dr. Versalovic will lead an in-depth analysis of the microbiome – the gut's complex community of digestive bacteria. In doing so, his team will look for changes in the microbiome that relate to autism symptoms and GI problems. Dr. Versalovic is a world pioneer in the study of the human microbiome. His team will also look for signs of metabolic disturbances in the children participating in the study.

The study will follow up on the promising results of the earlier research funded by Autism Speaks, in which scientists eased autism-like behaviors in a mouse model of autism by feeding the animals Bacteroides fragilis. The microbe occurs naturally in a healthy human intestinal tract. But it's not known if levels of B. fragilis – or other microbes – are different in persons with autism. Ultimately, the research may lead to stool tests that can guide personalized treatments for autism and its associated medical conditions.

The study will enroll 375 children, ages 4 through 12, at three sites: Baylor College of Medicine, Houston; the University of Texas Southwestern Medical Center, Dallas; and Nationwide Children's Hospital, Columbus, Ohio. Nationwide is part of the Autism Speaks Autism Treatment Network (ATN).

For comparison and analysis, these children will fall into five groups: those affected by autism and GI problems, those with autism and no GI problems, those with GI problems but not autism, those with neither autism nor GI disorders, and the unaffected siblings of children who have autism.

"This study is crucial to help us determine whether there are important differences in the microbiome of individuals with ASD and whether these differences are specific to ASD and GI problems," comments Paul Wang, Autism Speaks senior vice president and head of medical research. "It will also help us understand possible metabolic differences specific to ASD and GI problems."

"This knowledge will be critical in determining how to tailor future treatments, including probiotics," Dr. Wang adds. Probiotics are products that contain healthful bacteria.

Autism, constipation and oxidative stress

Dr. Levitt will lead a study exploring how thorough treatment of chronic constipation improves behavioral symptoms and biological stress in children with autism. The goal is to establish clear guidelines for personalizing treatments that can decrease both GI distress and autism symptoms. (Last year, Dr. Levitt was elected to the prestigious Institute of Medicine, part of the National Academy of Sciences.)

In the largest study of its kind, Dr. Levitt's team will recruit 120 children affected by autism through clinics affiliated with Children's Hospital Los Angeles and the University of California-Irvine. Both sites are part of the Autism Speaks ATN.

The children enrolled in the study will have chronic constipation, a condition unusually common among individuals with autism. Over the course of a year, they will receive the highest standard of care to address and relieve their constipation. At the same time, the researchers will assess changes in autism symptoms with behavioral tests and analyze blood samples for biochemical signs of oxidative stress. Previous studies have associated oxidative stress – a sign of cell damage – with autism and constipation.

For comparison, using data collected from children enrolled at other ATN sites, the researchers will track behavior and oxidative stress in children who have autism but are not affected by GI problems.

"This study will advance our understanding of the possible ripple effects of thorough treatment for constipation in individuals with ASD," Dr. Wang comments. "If it shows that successful GI treatment improves more than abdominal pain – if it helps children with ASD be more receptive to social interactions – we will have gained critical knowledge. It may well be that thoroughly addressing GI issues will significantly reduce the need for behavioral medications for many of our children."

Provided by Autism Speaks