Compared to their neurotypical classmates, children with autism spectrum disorder are more likely to develop gastrointestinal problems such as constipation and stomach pain. Stress, anxiety, despair, and social withdrawal are among the other internalizing symptoms that people feel at the same time. The causal link between gastrointestinal symptoms and internalizing symptoms has not yet been investigated in any studies.
In children and adolescents with autism, gastrointestinal problems and internalized symptoms have a “bi-directional” link, meaning that the symptoms appear to be affecting each other simultaneously, according to a recent study from the University of Missouri.
The results may have an impact on future studies in precision medicine that aim to provide individualized methods of treating gastrointestinal pain in autistic people.
“Research has shown gastrointestinal issues are associated with an increased stress response as well as aggression and irritability in some children with autism,” said Brad Ferguson, an assistant research professor in the MU School of Health Professions, Thompson Center for Autism and Neurodevelopmental Disorders and Department of Radiology in the MU School of Medicine. “This likely happens because some kids with autism are unable to verbally communicate their gastrointestinal discomfort as well as how they feel in general, which can be extremely frustrating. The goal of our research is to find out what factors are associated with gastrointestinal problems in individuals with autism so we can design treatments to help these individuals feel better.”
In the study, Ferguson and his team examined health information from over 620 autistic patients under the age of 18 who had digestive problems at the MU Thompson Center for Autism and Neurodevelopmental Disorders.
The researchers next looked at the connection between digestive problems and internalized symptoms including stress, worry, sadness, and social disengagement. Ferguson said the results offer additional proof of the significance of the “gut-brain axis,” or link between the brain and the digestive system, in gastrointestinal issues in autistic people.
“Stress signals from the brain can alter the release of neurotransmitters like serotonin and norepinephrine in the gut which control gastrointestinal motility, or the movement of stool through the intestines. Stress also impacts the balance of bacteria living in the gut, called the microbiota, which can alter gastrointestinal functioning,” Ferguson said.
“The gut then sends signals back to the brain, and that can, in turn, lead to feelings of anxiety, depression, and social withdrawal. The cycle then repeats, so novel treatments addressing signals from both the brain and the gut may provide the most benefit for some kids with gastrointestinal disorders and autism.”
Research has shown gastrointestinal issues are associated with an increased stress response as well as aggression and irritability in some children with autism. This likely happens because some kids with autism are unable to verbally communicate their gastrointestinal discomfort as well as how they feel in general, which can be extremely frustrating. The goal of our research is to find out what factors are associated with gastrointestinal problems in individuals with autism so we can design treatments to help these individuals feel better.
Brad Ferguson
To assist in resolving this complicated issue and creating therapies moving forward, according to Ferguson, an interdisciplinary team of professionals is required.
In addition to researching gastrointestinal issues in autistic people, David Beversdorf, a neurologist at the MU Thompson Center for Autism and Neurodevelopmental Disorders, works with Ferguson.
Beversdorf, who holds positions in both the MU School of Medicine and the MU College of Arts and Sciences, contributed to the discovery of particular RNA biomarkers linked to gastrointestinal problems in autistic children in a recent study.
“Interestingly, the study from Beversdorf and colleagues found relationships between microRNA that are related to anxiety behavior following prolonged stress as well as depression and gastrointestinal disturbance, providing some converging evidence with our behavioral findings,” Ferguson said.
Ferguson and Beversdorf are currently collaborating to study the impact of a stress-relieving drug on digestive problems in a clinical trial.
“I have a great relationship with Beversdorf and the MU Thompson Center Autism Research Core (ARC) that allows our team to quickly go from findings in the laboratory to clinical trials,” Ferguson said.
According to Ferguson, some treatments may be effective for some autistic people but may not be for everyone.
“Our team uses a biomarker-based approach to find what markers in the body are common in those who respond favorably to certain treatments,” Ferguson said.
“Our goal is to eventually develop a quick test that tells us which treatment is likely to work for which subgroups of patients based on their unique biomarker signature, including markers of stress, the composition of gut bacteria, genetics, co-occurring psychological disorders, or a combination thereof. This way, we can provide the right treatments to the right patients at the right time.”
“Bidirectional relationship between internalizing symptoms and gastrointestinal problems in youth with autism spectrum disorder” was recently published in the Journal of Autism and Developmental Disorders.
Ferguson also worked with Kyra Gynegrowski, an undergraduate student in the Marist College Department of Psychology, and Kristen Dovgan, an assistant professor in that department. The Autism Speaks Autism Treatment Network, now known as the Autism Care Network, provided funding for the study.
