Autism Spectrum Disorders (ASD’s) are neurodevelopmental disorders that include Autism, Asperger’s Syndrome and Pervasive Developmental Disorder Not Otherwise Specified (PDD-NOS). In recent years, scientific research has identified an association between ASD and compromised digestion. Of particular note, is the relationship between ASD and hyperpermeability syndrome. Hyperpermeability is a term given to a condition where the epithelial (tissue) barrier function of the small or large intestine is impaired. Impaired epithelial barrier function can result in less discrimination in the numbers and types of molecules and/or cells that are able to pass from the gastrointestinal tract to the circulatory system (bloodstream). Tight junctions (the staples holding the tissue cells together) are responsible for epithelial barrier function, connecting epithelial cells in the gastrointestinal lining. It is when these tight junctions lose their integrity that hyperpermeability can occur.
Previous scientific literature has clearly shown that the composition of dietary amino acids is able to alter tight junctions and intestinal permeability. In a recent study, undertaken at Rouen University, France, the amino acids glutamine and arginine were shown to have protective effects on intestinal permeability and tight junctions. Moreover, both intravenous and oral glutamine supplementation was associated with a lower risk of developing intestinal permeability. However, despite arginine proving beneficial in improving gut barrier function, no statistical, significant difference was shown in combining arginine and glutamine compared to using glutamine in isolation.