According to a recent study published in Molecular Autism researchers from Massachusetts General Hospital demonstrated that there is an alteration in blood-brain barrier integrity and function in individuals with autism spectrum disorder (ASD). 

According to the CDC 1 in 68 children are diagnosed with ASD. Families continue to search for the best treatments and commonly use a combination of therapies. Since the underlying causes of ASD are multifactorial there is no "one-size-fits-all" approach.

In this study researchers investigated the gut-brain axis in the pathophysiology of ASD and other neurodevelopmental disorders. This is the first study to look at the molecular signature of blood-brain barrier dysfunction in ASD from human patients.

Researchers analyzed postmortem cerebral cortex and cerebellum tissues from 33 individuals including 8 with ASD 10 with schizophrenia and 15 healthy controls. They found altered gene expression associated with blood brain barrier integrity and inflammation in the ASD patients confirming that an impaired blood-brain barrier associated with neuroinflammation contributes to ASD.

The gut-brain axis is an important component in the development of neurodevelopmental disorders. Thus the researchers also analyzed intestinal tissue samples from 12 individuals with ASD along with 9 healthy individuals. As a result 75% of those with ASD had a reduced expression of barrier-forming cellular components and 66% showed a higher expression of molecules that contribute to intestinal permeability.

It is critical to assess gut health in children with ASD. Many of these children have a dysbiosis and opportunistic infections and significantly different concentrations of certain bacteria in their stool compared to children without ASD. It is suspected that gut microbes can alter the levels of neurotransmitter-related metabolites affecting the gut-to-brain communication and alter brain function. Gluten and casein-free diets have been shown to offer some improvement in behavioral and gastrointestinal symptoms in children with ASD.

This new study is the first to show that an altered blood-brain barrier and impaired intestinal barrier might both play a role in neuroinflammation in people with ASD. In addition to stool testing an organic acid test is also a great tool to assess nutrient deficiencies oxidative stress and detoxification impairment. This would also look at neurotransmitter metabolism markers like kynuernate and quinolinate which I would expect to see elevated in these neuroinflammatory disorders. In addition individuals with ASD commonly have low serotonin which ties into the gut-brain axis. Researchers also link serotonin production and function to vitamin D and omega-3 fatty acids which suggests how these nutrients can support brain function and affect our behavior.

There continues to be more and more research linking intestinal permeability and behavior. It has already been demonstrated that children with ASD have altered composition of certain gut bacteria. Each persons biochemical individuality exerts a major influence on their health. Environmental exposures either pre- or postnatally filtered through genetic predisposition are fundamental factors in ASD and a successful treatment approach must include investigation into these factors. 

By Michael Jurgelewicz DC DACBN DCBCN CNS

Source: Maria Fiorentino Anna Sapone Stefania Senger Stephanie S. Camhi Sarah M. Kadzielski Timothy M. Buie Deanna L. Kelly Nicola Cascella Alessio Fasano. Blood–brain barrier and intestinal epithelial barrier alterations in autism spectrum disorders. Molecular Autism 2016; 7 (1)