Eixo Microbiota-Intestino-Cérebro E O Transtorno Do Espectro Autista: Revisão Sistemática

Abstract

Autism Spectrum Disorder (ASD) is a complex neurodevelopmental condition characterized by deficits in social communication and repetitive behaviors. Recent studies suggest that the

gut microbiota may play a crucial role in the pathophysiology of ASD through the microbiota- gut-brain axis. This study performed a systematic review of the literature with the aim of

investigating how alterations in the gut microbiota influence behavioral, cognitive, and gastrointestinal symptoms in individuals with ASD. Thirteen observational studies published between 2015 and 2025 were selected using the PubMed, Scielo, Lilacs, and ScienceDirect databases. Most studies demonstrated alterations in the microbiota composition of children with ASD, with reduced microbial diversity and increased potentially pathogenic microorganisms, such as Clostridium, Klebsiella, and Proteus. Reductions in bacteria producing butyrate, a short-chain fatty acid with anti-inflammatory and neuroprotective effects, were also observed. The findings point to a relationship between intestinal dysbiosis and changes in the metabolism of neurotransmitters, such as GABA and glutamate, in addition to an association with behavioral symptoms and gastrointestinal disorders. The influence of maternal factors, diet, and geographic location on the microbiome was also highlighted. Despite the methodological differences between the studies, the results reinforce the role of microbial imbalance in the neurobehavioral modulation of ASD. Modulation of the intestinal microbiota, through interventions such as probiotics and specific diets, appears to be a promising therapeutic approach, although more standardized and longitudinal research is needed to prove its effectiveness.