Gastrointestinal microbiota in children with autism in Slovakia.

Development of Autism Spectrum Disorders (ASD), including autism, is based on a combination of genetic predisposition and environmental factors. Recent data propose the etiopathogenetic role of intestinal microflora in autism. The aim of this study was to elucidate changes in fecal microbiota in children with autism and determine its role in the development of often present gastrointestinal (GI) disorders and possibly other manifestations of autism in Slovakia. The fecal microflora of 10 children with autism, 9 siblings and 10 healthy children was investigated by real-time PCR. The fecal microbiota of autistic children showed a significant decrease of the Bacteroidetes/Firmicutes ratio and elevation of the amount of Lactobacillus spp. Our results also showed a trend in the incidence of elevated Desulfovibrio spp. in children with autism reaffirmed by a very strong association of the amount of Desulfovibrio spp. with the severity of autism in the Autism Diagnostic Interview (ADI) restricted/repetitive behavior subscale score. The participants in our study demonstrated strong positive correlation of autism severity with the severity of GI dysfunction. Probiotic diet supplementation normalized the Bacteroidetes/Firmicutes ratio, Desulfovibrio spp. and the amount of Bifidobacterium spp. in feces of autistic children. We did not find any correlation between plasma levels of oxytocin, testosterone, DHEA-S and fecal microbiota, which would suggest their combined influence on autism development. This pilot study suggests the role of gut microbiota in autism as a part of the "gut-brain" axis and it is a basis for further investigation of the combined effect of microbial, genetic, and hormonal changes for development and clinical manifestation of autism.