In Autism, the Importance of the Gut

Behavior problems may be explained by serotonin and bacteria in the bowels.

Michael, an autistic boy living in New York City, started scratching and picking at his face when he was about seven years old. Before long, he was gnawing on the side of his thumb. Along the bottom of his stomach, he tore cuts so deep that they scarred.

Over the next five years, a series of psychiatrists prescribed psychotropic medications to correct the self-mutilation. But nothing seemed to help. By age 12, he'd been taken out of school because he was a constant disruption. Though his parents wanted him to live at home, they decided he could be better cared for in a residential facility.

"These kids just live in a very fine balance. And when anything is off, they regress."

As they prepared to move Michael to the group home, his family was referred to Dr. Kara Margolis. Margolis, 36, is a pediatric gastroenterologist at New York Presbyterian Hospital and a researcher at Columbia University Medical Center. She speaks with contagious enthusiasm and the slightest hint of a Brooklyn accent. By the time she met Michael, bloody scabs dotted his face, from the tender skin below his eyes to the tips of his ears. He'd chewed his thumb down nearly to the bone. There was blood everywhere, Margolis recalls as she describes their first visit. He screamed and paced the room throughout the brief exam.

Until recently, psychiatrists have mainly been handling these kinds of behavioral changes. "A lot of these kids, before they see me, have been trialed on many different psychotropic drugs to try to relax them, to calm them down," Margolis explained on a Wednesday morning in April, as she sat at her cluttered desk in the gastroenterology research lab at Columbia. "Sometimes they work and sometimes they don't."

Dr. Kent Williams, a pediatric gastroenterologist at Nationwide Children's Hospital in Columbus, Ohio, agrees that many doctors are reluctant to consider other possibilities. "My heart goes out to the parents, because this is a daily struggle," he said. "Some physicians don't know what to do, so they give up."

Margolis, Williams and a handful of doctors across the country take a different approach. Instead of concentrating on the brain, they treat the gut.

IMG_2895inset.jpgDr. Kara Margolis examines a patient. [Danielle Elliot]

"Many doctors don't recognize that aggressive behavior is not part of autism," Margolis said. "This is really a new field." Research is showing that a common cause of autistic children acting out is simply because they're constipated -- which, from there, can mean they stop sleeping and eating well. They may become aggressive and frustrated because they have no other way of saying that their stomachs hurt.

Approximately one in 88 children in the U.S. has an autistic spectrum disorder. Up to 70 percent of them have gastrointestinal (GI) abnormalities at some point during childhood or adolescence. They are 3.5 times more likely to have constipation or chronic diarrhea than children who are not autistic. For years, parents have tried altering their children's diets to alleviate the issues, often restricting or completely eliminating gluten and dairy. But there is little scientific evidence supporting these dietary changes. Still signs keep pointing back to an underlying biological link between autism and GI issues.

A study published last year in the Journal of Abnormal Child Psychology linked the GI issues with behavior, showing that autistic children who have GI issues often experience extreme anxiety as well as regressions in behavior and communication skills. What's worse, the side effects of the psychotropic drugs that are prescribed to many autistic children may be intensifying the digestive issues. Once the GI issues are treated, aggressive and problematic behaviors sometimes subside.

At her first visit with Michael, Margolis suspected that he was nauseous and constipated, conditions that generally manifest in the area of the stomach where he was scratching. The nausea would explain why he often gagged and salivated during meals. She couldn't take x-rays because he was so hyperactive, but Margolis followed her instincts and treated him for constipation and reflux (gastritis).

When Michael came in for his follow-up one month later, the scabs on his face were healing. He'd stopped biting and scratching; he sat through the exam. His mother cried in the exam room, seemingly amazed that over the five years that his behavior deteriorated, no other doctors had recognized the GI issues.

Today, he is back in school and living with his family. He is still very sensitive to the slightest bit of constipation, but as long as his GI issues remain in control, so do his behaviors.

"These are kids who, their whole lives turned around when we treated the GI issues," Margolis said. "They're not miracles. They seem like miracles, but really all it takes is a recognition that GI things happen in these kids and they manifest in very different ways than in kids who are not autistic." Understanding how GI issues manifest differently in autistic children could lead to new treatments and pharmaceuticals targeted specifically to the autistic community.

Dr. Kara Margolis consults with a patient's mother. [Danielle Elliot]

There are several theories behind the link between GI issues and autism, and whether abnormal gut development precedes or contributes to abnormal neurological development. There is no evidence to say that GI issues and autism have a causal relationship in either direction. The first step to improving treatments is to understand the underlying link between the two conditions.

Scientists at U.C. Davis, supported by a $770,000 grant from Autism Speaks, are concentrating on bacterial overgrowth in the gut and potential antibiotic treatments that would help the gut function more normally. At the University of Toronto, neuroscientist Derrick MacFabe is researching the relationship between gut bacteria and brain development.

Margolis is also investigating the role of gut bacterial overgrowth -- as well as that of serotonin.

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Danielle Elliot is a writer and multimedia producer based in New York.

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