Seeking Answers to the Gut-Brain Connection in Autism

Gastrointestinal problems among children with autism appeared more frequently than in other kids

(RxWiki News) Children with autism may experience other conditions beyond the spectrum of symptoms linked to their developmental disorder. But could those other conditions relate to their autism?

A recent study found that gastrointestinal problems appeared to be more common among children with autism than among typically developing children.

Children without autism but with developmental delays also appeared to experience a greater number of gastrointestinal problems.

These problems ranged from stomach upset or diarrhea to bloating or vomiting.

The researchers suspect that there could be a connection between the gastrointestinal symptoms and the developmental delays or disorders that some children have.

"Tell your child's doctor about his/her gastrointestinal problems."

This study, led by Virginia Chaidez, a postdoctoral student in the UC Davis Department of Public Health Sciences when she did this research, looked at whether gastrointestinal problems were more common among children with autism or developmental delays.

The researchers compared gastrointestinal symptoms experienced among 960 children, aged 2 to 5, involved in an ongoing study.

The group included 499 children with autism spectrum disorders, 137 children with developmental delays and 324 children without autism or developmental delays.

Having a developmental delay was based on the children's scores on assessment tools designed to determine whether a child's development was on track.

The researchers investigated how frequently the children experienced any of the following gastrointestinal problems: abdominal pain, gas/bloating, diarrhea, constipation, pain while going to the bathroom, vomiting, sensitivity to foods, difficulty swallowing, blood in the child's feces or blood in the child's vomit.

The researchers found that children with autism spectrum disorder had about eight times higher odds of experiencing at least one frequent gastrointestinal symptom compared to children without autism or developmental delays.

Children with developmental delays had about 4.5 times greater odds of having at least one frequent gastrointestinal symptom compared to typically developing children.

The children had also been given assessments related to their behavior and temperament.

Among children with autism, those with more abdominal pain, gas, diarrhea, constipation or pain while going to the bathroom were also more likely to have greater irritability, social withdrawal symptoms and hyperactivity.

Children with autism with more gastrointestinal symptoms also showed more "stereotypy," which is the word describing repetitive movements such as rocking back and forth or moving another body part back and forth.

The researchers therefore concluded that gastrointestinal problems were much more common among children with autism or developmental delays than among typically developing children.

Because these problems appeared to affect children's poor behaviors, the conditions require attention, the researchers also wrote.

They suggested that investigating the stomach and gastrointestinal problems may reveal insights into autism since the gut is sometimes thought of as the "second brain" of a person.

The "second brain" concept comes from some evidence that chemical messengers in the gut appear to influence the brain and vice versa.

"Investigating the dual role of neurotransmitters active in both the gut and the brain in future studies may advance our understanding of underlying mechanisms important to both," the researchers wrote.

This study was published November 6 in the Journal of Autism and Developmental Disorders. The authors declared no potential conflicts of interest.

The research was funded by National Institutes of Health, National Institute of Environmental Health Sciences, the Environmental Protection Agency through the Science to Achieve Results (STAR) program, Medical Investigations of Neurodevelopmental Disorders (MIND) Institute and Autism Speaks.

Review Date: 
November 7, 2013