The role of probiotics in children with autism spectrum disorders: A study protocol for a randomised controlled trial.

BACKGROUND: Autism spectrum disorder (ASD) is a neurological and developmental condition that begins in infancy or earlier and lasts through the individual's lifetime. The aetiology and mechanisms of ASD are not yet fully understood, and current treatment comprises mainly education and rehabilitation, without significant improvement in the core symptoms. Recent studies suggest that microbiota change in children with ASD after the ingestion of probiotics may improve the balance of microbiota and thus ASD symptoms. OBJECTIVE: The objectives of this study are to evaluate the efficacy of probiotics on the symptoms of children with ASD and the possible mechanisms involved. METHODS: This is a prospective controlled trial. A total of 160 children with ASD will be stratified and allocated to placebo and probiotics groups randomised according to the severity of their ASD symptoms. The probiotics group will be given probiotics supplements orally twice a day for 3 months and the control group will be given a placebo at the same amount, in addition to the baseline therapy of education and rehabilitation. All the children will be evaluated systematically by using different scales, questionnaires before, during, and after 3 months' treatment, as well as 3 months after discontinuation. The potential impact of probiotics on immunity and inflammation, metabolism, and metagenome will also be investigated. DISCUSSION: Our previous study showed that the abundance of intestinal flora was greatly different in children with ASD, and that Bifidobacterium was associated with the severity of ASD. In the present study, we will investigate the impact of probiotics supplementation on the symptoms of Children with ASD, with the purpose of evaluating the possible therapeutic effects of additives on ASD and of providing a reference for clinical treatment. The results will help to disclose as yet unknown relationship between probiotics and ASD. TRIAL REGISTRATION: This study has been registered with Chinese Clinical Trial Registry (ChiCTR-2000037941).