Gut microbiota changes in children with autism spectrum disorder: a systematic review

• Main Authors: Lucius Kang Hua Ho, Valerie Jia Wei Tong, Nicholas Syn, Niranjan Nagarajan, Elizabeth Huiwen Tham, Stacey K. Tay, Shefaly Shorey, Paul Anantharajah Tambyah, Evelyn Chung Ning Law
• Format: Article
• Language: English
• Published: BMC 2020-02-01
• Series: Gut Pathogens
• Subjects: Microbiome; Microbiota; Dysbiosis; Systematic review; Autism spectrum disorder
• Online Access: https://doi.org/10.1186/s13099-020-0346-1

Abstract Background As more animal studies start to disentangle pathways linking the gut microbial ecosystem and neurobehavioral traits, human studies have grown rapidly. Many have since investigated the bidirectional communication between the gastrointestinal tract and the central nervous system, specifically on the effects of microbial composition on the brain and development. Methods Our review at the initial stage aimed to evaluate literature on gut microbial alterations in pediatric neurobehavioral conditions. We searched five literature databases (Embase, PubMed, PsychInfo, Scopus, and Medline) and found 4489 published work. As the mechanisms linking gut microbiota to these conditions are divergent, the scope of this review was narrowed to focus on describing gut dysbiosis in children with autism spectrum disorder (ASD). Results Among the final 26 articles, there was a lack of consistency in the reported gut microbiome changes across ASD studies, except for distinguishable patterns, within limits, for Prevotella, Firmicutes at the phylum level, Clostridiales clusters including Clostridium perfringens, and Bifidobacterium species. Conclusions These results were inadequate to confirm a global microbiome change in children with ASD and causality could not be inferred to explain the etiology of the behaviors associated with ASD. Mechanistic studies are needed to elucidate the specific role of the gut microbiome in the pathogenesis of ASD.