CORRELAÇÃO FISIOPATOLÓGICA ENTRE DISBIOSE INTESTINAL E DOENÇA DE ALZHEIMER: UMA REVISÃO LITERÁRIA

Abstract

Introduction: The intestinal microbiota comprises approximately 100 trillion microbial cells, encompassing 95% of symbiotic microorganisms residing in the human body. Metabolites produced by the intestinal microbiome are believed to influence gut-brain communication. Therefore, the phenomenon of dysbiosis and its potential implications in the pathophysiology of various diseases, such as Alzheimer's disease (AD), are highlighted. Methods: A search was conducted in PubMed and Embase using the keywords "Alzheimer Disease", "Dysbiosis", "Brain-Gut Axis", "Gastrointestinal Microbiome". Results: 233 articles were found, screened in the Rayyan platform based on title (n = 116), abstract (n = 39), and full-text reading (n = 6). Discussion: The microbiota-gut-brain axis constitutes a bidirectional communication system between cognitive centers in the brain. There are several pathways between these organs, and their dysfunction or interruption can affect intestinal motility and secretion. Specifically in AD, alterations in the microbiota have been observed, characterized by an increase in pro-inflammatory bacteria and a decrease in anti-inflammatory bacteria, leading to impaired gastrointestinal permeability. In this context, studies suggest that the presence of immunoinflammatory variations in patients with mild cognitive impairment and AD could generate reactive oxygen species, resulting in neuroinflammation and cell death. Conclusion: Dysfunction of the microbiota-gut-brain axis, related to intestinal dysbiosis, has been associated with the pathological cascade of AD. Therefore, the intestinal microbiota and its synthesized substances become potential therapeutic targets, necessitating further research to elucidate the correlation between dysbiosis and Alzheimer's disease.