Autism and hormones: A perspective from the immune system and the gut microbiome

Autism Spectrum Disorder (ASD) affects 2.7 % of individuals worldwide, and it is characterized by abnormal social interactions, communication deficits, restricted interactions, and repetitive behaviors. This disorder appears early in life, and it has been diagnosed more frequently in males than in females. Several factors have been shown to be associated with the onset of ASD. However, the mechanisms underlying the onset of this neurodevelopmental disorder and the higher prevalence in males remain unclear. This review discusses the role of hormonal imbalances, immune system activation during the prenatal (maternal immune activation) and the neonatal periods (neonatal immune activation), immune dysregulation and gut dysbiosis in the development of ASD. It also highlights the many interactions between these systems and demonstrates the true complexity of this disorder.