The association between intestinal microbiota and autism spectrum disorder

Abstract

Objective: To review the literature on changes in gut microbiota and their relationship with autism.
Methods: Integrative review with a search strategy based on the guiding question: “What are the existing associations between gut microbiota and autism spectrum disorder (ASD)?” The search was conducted in the PUBMED and BVS databases, including full-text articles in Portuguese and English, published between 2019 and 2023. Studies that were duplicates or addressed neurodevelopmental disorders without a specific focus on autism were excluded. Results: Of the 355 articles found, only 12 met the inclusion criteria. The studies highlight that ASD involves multiple factors, including changes in the gut microbiome. Intestinal dysbiosis is identified as both a consequence and an aggravating factor of autistic symptoms, forming a feedback loop. Microglial cells, involved in the innate immune response in the CNS, are also implicated.
Final considerations: Differences in the gut microbiota composition of children with ASD were observed, with a decrease in Bacteroides, Bifidobacterium, and Enterococcus, and an increase in Lactobacillus, Ruminococcus, and Escherichia-Shigella. These findings may provide relevant insights into the role of the microbiome in the pathophysiology of autism.