A Systematic Review of the Role of Prebiotics and Probiotics in Autism Spectrum Disorders

Abstract

Background: Autism spectrum disorder (ASD) is a complex developmental condition typically characterized by deficits in social and communicative behaviors as well as repetitive patterns of behaviors. Despite its prevalence (affecting 0.1% to 1.8% of the global population), the pathogenesis of ASD remains incompletely understood. Patients with ASD are reported to have more frequent gastrointestinal (GI) complaints. There is some anecdotal evidence that probiotics are able to alleviate GI symptoms as well as improve behavioral issues in children with ASD. However, systematic reviews of the effect of prebiotics/probiotics on ASD and its associated symptoms are lacking. Methods: Using the keywords (prebiotics OR probiotics OR microbiota OR gut) AND (autism OR social OR ASD), a systematic literature search was conducted on PubMed, EMBASE, Medline, Clinicaltrials.gov and Google Scholar databases. The inclusion criteria were original clinical trials, published in English between the period 1st January 1988 and 1st February 2019. Results: A total of eight clinical trials were systematically reviewed. Two clinical trials examined the use of prebiotic and/or diet exclusion while six involved the use of probiotic supplementation in children with ASD. Most of these were prospective, open-label studies. Prebiotics only improved certain GI symptoms; however, when combined with an exclusion diet (gluten and casein free) showed a significant reduction in anti-sociability scores. As for probiotics, there is limited evidence to support the role of probiotics in alleviating the GI or behavioral symptoms in children with ASD. The two available double-blind, randomized, placebo-controlled trials found no significant difference in GI symptoms and behavior. Conclusion: Despite promising preclinical findings, prebiotics and probiotics have demonstrated an overall limited efficacy in the management of GI or behavioral symptoms in children with ASD. In addition, there was no standardized probiotics regimen, with multiple different strains and concentrations of probiotics, and variable duration of treatments.

Composition of Gut Microbiota in Children with Autism Spectrum Disorder: A Systematic Review and Meta-Analysis

“…This may increase the chances of individualized and successful therapies, increasing the health quality of people suffering from ASD. However, the results are still controversial, and further studies are required to assess the effect of what are known as "psychobiotics" on neurological disorders [25,[71][72][73].…”

The Circadian Clock as an Essential Molecular Link Between Host Physiology and Microorganisms

“…Moreover, L. reuteri reversed social deficits in a variety of ASD models (Buffington et al, 2016;Sgritta et al, 2019). Limited information is available regarding autistic patients, although some open clinical trials indicate amelioration of both GI and behavioral symptoms (Ng et al, 2019). However, nobody has explored the possibility of administrating probiotics following chrono-pharmacology principles, even though the benefits could be enhanced because the gut ecosystem of bacteria oscillates in a daily fashion, in part following the metabolic and energy needs of the host and perhaps of the brain itself.…”

Gut instincts: vitamin D/vitamin D receptor and microbiome in neurodevelopment disorders

“…Some growing ideas to reduce GI irregularities and ASD severity including supplementation of probiotics or prebiotics and fecal microbiome transplant (FMT) have been examined in ASD clinical trials [ 37 ]. Probiotics are presumably thought to enhance GI health by reducing gut barrier permeability [ 38 ]. A probiotic (Vibosome containing Lactobacillus and Bifidobacterium ) was administered to 13 ASD children (ages 3–12 years) to treat GI symptoms for a 19-week trial period.…”