Unraveling the relative abundance of psychobiotic bacteria in children with Autism Spectrum Disorder

Autism Spectrum Disorder (ASD) is a complex neurodevelopmental disorder characterized by social deficits. Accumulated evidence has shown a link between alterations in the composition of gut microbiota and both neurobehavioural and gastrointestinal symptoms in children with ASD which are related to the genera Lactobacillus and Bifidobacterium. These genera have been recently categorized as "psychobiotics". Moreover, this study aimed to compare the relative abundance of psychobiotics (L. plantarum, L. reuteri, and B. longum) to the total gut microbiome in typically developing (TD) children and those with ASD in order to correlate the distribution of psychobiotic with the severity and sensory impairments in autism. The ASD children were assessed using the Childhood Autism Rating Scale (CARS), while sensory impairments were evaluated using the Short Sensory Profile (SSP). Furthermore, the gut microbiome was analyzed using the quantitative real-time PCR. The study revealed a statistically significant increase in the relative abundance of L. reuteri and L. plantarum in the TD group in comparison to ASD children. Regarding the SSP total score of ASD children, a statistically significant negative correlation was found between both Lactobacillus and L. plantarum with the under-responsive subscale. For the Autism Treatment Evaluation Checklist (ATEC) score, B. longum and Lactobacillus showed a significant positive correlation with Health/Physical/Behaviour.