Recent evidence implicates immune alterations and gut microbiota dysbiosis in at least some subpopulations of individuals with autism spectrum disorder ( ASD). Immune and gut alterations in ASD have mostly been studied separately, and the reviews and theoretical models up to now have mainly considered the immune system as one of the routes for gut-brain communication. We take a different perspective and consider possible common mechanisms of action for the gut microbiota and inflammation on the neural basis of ASD. We propose these to be their effects on ASD-susceptibility genes, neurodevelopment, and intestinal and blood-brain barrier integrity. We then use these common mechanisms to offer pathways for potentially beneficial effects of early-life probiotics on the neural development in ASD. This new perspective yields a conceptual framework for creating effective preventions for mothers at risk of giving birth to children with ASD. Such a framework may also inform effective interventions targeting these common mechanisms of action, which may be shared in many ASD cases regardless of their different etiological profiles. Probiotics may be one example of such preventions and interventions. Finally, the common mechanisms offered by this perspective can be useful in the search of comprehensive theories that can account for the complete neurobiological and behavioral symptoms of ASD. (C) 2018 IBRO. Published by Elsevier Ltd. All rights reserved.