Gastrointestinal Disorders in ASD: Cause or Consequence?

October 25, 2021

Interview with Dr. Stephen Walker Explores This Fascinating Question

Expert autism researchers Arthur Krigsman, M.D. and Stephen Walker, Ph.D. have published a new mini-review examining GI dysfunction and its relationship to autism spectrum disorder (ASD). The co-authors evaluated over 50 papers in order to make observations about this yet-to-be-determined relationship.

SafeMinds recently had the pleasure of interviewing Dr. Walker to discuss this exciting new paper. The text of this interview follows.

In your new mini-review article, you and Dr. Krigsman ask the question, if an untreated gastrointestinal disorder can directly impact neurodevelopment or, conversely, whether having a neurodevelopmental disorder predisposes a child to chronic GI issues. Ultimately, you both determined that an untreated GI disorder could cause neurodevelopmental damage. Can you briefly explain why?

We do not mean to imply that an untreated gastrointestinal disorder is exclusively a unidirectional process and that the only mechanism of brain injury in autism is from the bowel. What we are saying is that too often the immediate assumption of most practitioners, whether they are psychiatrists, pediatricians, or family practitioners, is that the brain dysfunction associated with autism somehow leads to G.I. problems. And this assumption may lead the practitioner to overlook an underlying treatable gastrointestinal disease. What the review is pointing out is that the totality of published data using the human gastrointestinal biopsy tissue to understand the basis of intestinal inflammation in autism (and by extension the basis of G.I. symptoms and autism) points to the frequent presence of an autoimmune inflammatory process that begins in the gut and whose metabolic and molecular derivatives may be transferred systemically via the blood to the brain where it can cause further injury.

Do you think the average pediatrician or developmental pediatrician understands the connection between autism and GI disease?

My experience over the past 20 years has shown me that most practitioners may be aware that G.I. “problems” often occur in children and adults with autism, but they are not aware that there is a mechanistic connection between the gut and brain, and they certainly are not usually aware that these “G.I. problems” are largely treatable. I often feel that there is a medical practitioner bias of sorts when it comes to children with developmental difficulties and that they somehow automatically are expected to have gastrointestinal symptoms, and that these gastrointestinal symptoms should be accepted as part of having autism.

           In the mini-reviews conclusion, there is a call to conduct a prospective treatment study to determine if standard immunotherapy for Inflammatory Bowel Disease (IBD) improves GI symptoms and if these improvements could lead to improvements in cognition and behaviors for those with autism. Can you explain what standard immunotherapy is for IBD? And do you know if any research is currently taking place to study your conclusion?

The autism-associated inflammatory bowel disease is typically most often treated with a combination of initial corticosteroids followed by either immunomodulator therapy such as methotrexate or 6-mercaptopurine and an oral anti-inflammatory agent specifically designed to be effective in the gastrointestinal tract (e.g., various forms of mesalamine). Over the years, it has become apparent that the newer classes of biologic agents are also often very helpful in treating inflammatory bowel disease and their consequent gastrointestinal symptoms. Medications can be combined for optimal effect. Other methods of modifying intestinal mucosal inflammation include alteration of the bowel flora with either antibacterial or antifungal medications or probiotics. Surprisingly, we have found that the majority of children experiencing a marked improvement or resolution of their G.I. symptoms/disease also make cognitive and behavioral gains at a rate faster than that which would be expected from simply ‘feeling better’ alone. We currently have a clinical observation study underway whose goal is to provide objective data regarding GI symptom improvement and improvement in autism-related behavior and cognition in response to effective treatment of a child’s inflammatory bowel disorder. 

What’s the take-away from this mini-review?

To put it very simply, the take-home message of this paper is that children with ASD and comorbid gastrointestinal symptoms that are refractory to simple inventions such as brief use of laxatives and treatment for gastroesophageal reflux disease should undergo a comprehensive gastrointestinal evaluation by a pediatric gastroenterologist knowledgeable about the variety of treatable pathologies seen in ASD. Most importantly, this clinician needs to be aware of the unusual ways that a non-communicative or poorly communicative patient exhibits G.I. symptoms. In the case of a psychiatrist and primary care physician, they need to be aware that extremes of “ASD behavior” may be the sole manifestation of a treatable underlying gastrointestinal pathology. Lastly, this information should serve as a reminder to all of us clinicians that we need to listen carefully to the parents of the child and their caretakers and therapists. This is because they are at the frontlines and know the children the best. They therefore will know when there is a change in the child’s behaviors/cognition, and they are best able to determine whether these behaviors border on the extreme or if they are of the less extreme type that is actually characteristic of children with ASD.

Original Study

Show Buttons
Hide Buttons