Abstract
The role of the gut microbiota in triggering autism is a rapidly emerging field of research. Gut microbiota have been incriminated because autistic children often have gastrointestinal symptoms. Pathogenic gut bacteria in children with autism spectrum disorders (ASD) have been reported. The present study aimed to assessClostridium difficilein the stool of children with ASD and its relation to gastrointestinal (GI) comorbidities, autism severity, and sensory impairment. The study included 58 ASD patients, 45 of their neurotypical siblings, and 45 unrelated controls. Childhood Autism Rating Scale (CARS) was used to assess the severity of autism. Sensory problems were evaluated using the Short Sensory Profile (SSP). GI symptoms were assessed with a modified six-item GI Severity Index (6-GSI) questionnaire. Quantitative real-time PCR was done for the detection and quantitation ofC. difficileand its toxins A and B.C. difficilewas detected in 25.9%, 40%, and 15.6% of ASD cases, siblings, and unrelated control respectively. Regarding toxin A and B production, 73.3%, 77.8%, and 71.4% ofC. difficilein positive ASD, siblings, and unrelated control cases respectively were toxigenic. There was no statistically significant difference between the three groups as regardsC. difficilequalitative, quantitative, and toxin production results. In conclusion,C. difficileis not specifically prevalent in the gut of children with ASD. Although most of the strains are toxigenic, there were no GI symptoms in the control groups and no statistically significant association with GI Severity Index in autistic cases. Gastrointestinal dysfunction and sensory impairment are common comorbidities in ASD.