Elucidating the interplay between gut microbiota and autism spectrum disorder. New insights and therapeutic perspectives.

Autism is a complex neurodevelopmental disorder characterized by a wide range of cognitive, behavioural and communication impairments. Children with autism have a distinctive and underdeveloped range and volume of gut bacteria (microbiome) which is often not related to their diet. Evidence gathered throughout years of research suggests that the pathway between gut bacteria and the central nervous system, referred to as the gut-brain axis (GBA), has a profound effect on the social behaviours of autistic children. The gut microbiome has been shown to play a vital role in the manifestation of autism spectrum disorder (ASD) symptoms as gut dysbiosis - an imbalance in the gut microbiome - affects brain development through processes regulated by the neuroendocrine, neuroimmune and autonomic nervous systems. Although dysregulation of the gut microbiome and subsequent disruption of GBA are thought to contribute to the pathogenesis of autism, the underlying mechanisms and the extent to which the microbiome contributes to neurodevelopmental disorders remain unclear. In this review, we focus on understanding the complex and multidirectional interplay between gut microbiota and ASD based on evidence mounted over the years. Furthermore, we examine how genomics, metabolomics and microbiome components can be integrated to unravel this multifactorial disorder. The ability to understand the underlying mechanisms involved in ASD will pave the way for future advancements in therapy and treatment.