It may seem a bit counterintuitive, but treating the pancreas of a child with autism could help ease problematic behaviors, new research shows.

The key here, researchers say, is the link between dietary protein intake and crucial brain neurotransmitter chemicals, such as serotonin and dopamine. 

When those neurotransmitters aren't working as they should, that can affect children's behavior, explained a team at the University of Texas Health Science Center at Houston.

Kids with an autism spectrum disorder often show strong preferences for carbohydrate-rich food like pasta and bread, while resisting protein-rich fare. But the amino acids needed to produce neurotransmitters can only be obtained from protein, the Houston team explained. 

They theorized that giving kids a pancreatic enzyme replacement supplement — aimed at boosting amino acid production by the pancreas — might help kid's brains and ease problem behaviors that are linked to deficiencies in brain neurotransmitters.

The new trial was led by Deborah Pearson, professor of psychiatry and behavioral sciences at McGovern Medical School at UTHealth Houston. 

“Children who have ASD often have a number of co-occurring maladaptive behaviors, such as irritability. We wanted to know whether these maladaptive behaviors can be addressed by an intervention with a low risk of side effects,” she said in a UTHealth news release. 

The study included 190 children, ages 3 to 6, who were living with ASD.

In the trial's first phase, lasting three months, 92 of the kids got a special pancreatic enzyme replacement supplement sprinkled on their food three times each day, while the other 98 got a "dummy" placebo supplement. Neither the researchers nor the children's parents knew which child was getting the supplement or a placebo.

During this phase, parents whose children got the supplement reported "significant decreases in their child’s symptoms of irritability, hyperactivity/noncompliance, and inappropriate speech," the news release said. That wasn't the case for kids who received the placebo. 

In the trial's second phase, all of the kids got the active pancreatic enzyme replacement daily for six months. 

During that phase, parents reported a significant ebbing of irritability, hyperactivity and inappropriate speech, as well as declines in lethargy and social withdrawal, Pearson's team said. 

“This study demonstrated that pancreatic enzymatic replacement — which is thought to enhance the supply of essential amino acids necessary for the synthesis of neurotransmitters — was associated with improved behavioral function in preschoolers with ASD, with minimal side effects,” she said.

The study was funded by Curemark, which is developing the pancreatic enzymatic replacement, and was published recently in JAMA Network Open.