Gut–Brain Inflammation and Disrupted Homeostasis Due to Activation of Mast Cells and Microglia

Recent data from the Centers for Disease Control (CDC) indicate that the incidence of Autism Spectrum Disorder (ASD), a neurodevelopmental disorder characterized by deficits in social communication and the presence of restricted interests and repetitive behaviors, has increased to 1 in 31 children. Individuals with ASD have a constellation of neurological, behavioral, sensory, feeding, gastrointestinal, and immunological issues. Even though there is some genetic component to the pathogenesis of ASD, accumulation of environmental and pathogenic toxins could contribute to disruption of the gut–blood-barrier (GBB) and blood–brain barrier (BBB) via activation of mast cells (MCs) and microglia, resulting in a chronic cycle of gut–brain inflammation. Here we discuss how various environmental, pathogenic, and stress factors can disrupt gut–brain homeostasis to create susceptibility and epigenetic effects that contribute to the development of ASD. We also suggest simple ways to address some of the key pathogenetic processes involved in ASD.