Abstract
Children with autism spectrum disorder (ASD) are 4 times as likely to experience gastrointestinal symptoms as children without ASD. The gut microbiota has increasingly been the subject of investigation as a contributing factor to these symptoms in this population because there is evidence to suggest that alterations in the intestinal microflora are correlated with gastrointestinal and ASD symptom severity. Probiotic therapy has been proposed as a treatment for augmented gastrointestinal symptom severity in children with ASD. This narrative review systematically searched the literature to provide an update for practitioners on the state of the evidence surrounding probiotic therapy in children with ASD as a treatment option for reducing gastrointestinal symptoms. A total of 186 articles were screened and 5 articles met the inclusion criteria. A collective sample of 117 children with ASD is represented and outcomes addressed include improvement in gastrointestinal symptoms as well as influence of probiotic supplementation on the gut microbiota and ASD symptoms and behavior. There is promising evidence to suggest that probiotic therapy may improve gastrointestinal dysfunction, beneficially alter fecal microbiota, and reduce the severity of ASD symptoms in children with ASD. Future research is still warranted in this area because there are methodologic flaws in the available literature and optimal species, strains, dosages, and duration of treatment have not been identified.