The Link Between Autism and Gastrointestinal Issues

Children with autism often display a variety of neurological symptoms, including repetitive behaviors, fixation on routine, and delayed speech and language skills. These symptoms, along with dozens of others, greatly vary in severity between kids on the autism spectrum. Recent studies have highlighted gastrointestinal (GI) issues as another extremely prevalent disorder for children with autism. Despite the lack of clear neurological ties to other symptoms of autism, a recent study showed that out of 176 children with autism, 93.2% presented with at least one GI issue, and 88.1% presented with multiple (Chakraborty et al., 2020). These symptoms include food sensitivity, abdominal pain, chronic diarrhea, and constipation, among others. It is not clear if GI issues are a core part of autism, or are simply a result of other symptoms or treatments. Many studies have shown that children with autism generally ingest more antibiotics throughout their childhood (Krajmalnik-Brown et al., 2015). This has the potential to greatly influence the diverse gut microbiota, and possibly cause GI issues. However, there is not conclusive evidence that this is the cause of, or even correlated with, the GI issues found in autistic children.

The prior study that confirmed the prevalence of GI issues in children with autism also found a positive correlation between the severity of repetitive behaviors and GI issues in their patients. However, the study did not find a strong correlation between GI issues and social skills or communication (Ohio State University, 2020). Payal Chakraborty, a researcher involved in the study, posits that increased repetitive behaviors could simply reflect attempts to self soothe or cope with discomfort (Ohio State University, 2020). Other researchers agree, postulating that the discomfort associated with GI issues likely increases frustration and aggression, and decreases concentration, exacerbating preexisting symptoms of autism (Krajmalnik-Brown et al., 2015).

Other researchers think there are more direct pathways that could create this correlation. Elaine Hsiao considers the vagus nerve, and its role in carrying information about the intestines, combined with its role in modulating anxiety and stress. In her publication, she mentions that disruptions to the GI tract can affect the stimulation of the vagus nerve and can influence emotional behavior, alluding to the discovery made by Chakraborty (Hsiao, 2014). This is certainly plausible given the longstanding knowledge that gut health can influence and even trigger mood and anxiety disorders in non-autistic individuals.

Overall, there is a clear correlation between GI issues and repetitive autistic behavior, but there is no consensus about the root of this correlation. Further studies analyzing vagus nerve activity, gut flora, or medicine intake in conjunction with autism and GI issues may shed more light on the subject.