Relação entre microbiota intestinal e doenças neurodegenerativas

Abstract

INTRODUCTION: The gut microbiota (GM) is composed of trillions of microorganisms that perform essential functions in maintaining the organism’s homeostasis. Recent evidence demonstrates that alterations in this ecosystem are associated with increased

intestinal permeability, abnormal immune activation, and the release of pro- inflammatory metabolites—factors that may contribute to neurodegenerative diseases

(ND), such as Alzheimer’s and Parkinson’s. The gut- brain axis, mediated by neural, endocrine, and immune pathways, has been identified as one of the main mechanisms underlying this interaction. OBJECTIVES: To analyze the relationship between the gut microbiota and the development of neurodegenerative diseases, highlighting the mechanisms involved and the possibilities for therapeutic intervention. METHODOLOGY: This is a literature review study, conducted in the SciELO and PubMed databases, using the descriptors “Gut microbiome OR Microbiota intestinal”, “Brain-gut axis” AND “Gastrointestinal microbiome and neurodegenerative diseases”. Full, open-access articles published between 2020 and 2025 in Portuguese, English, and Spanish were included. After applying exclusion criteria, 28 articles were selected to support this research. RESULTS: The reviewed studies revealed that intestinal dysbiosis may be related to neuroinflammation and the accumulation of pathological proteins, such as beta- amyloid in Alzheimer’s and alpha-synuclein in Parkinson’s disease. Changes in bacterial composition, reduced production of short-chain fatty acids, and increased translocation of lipopolysaccharides were identified as relevant risk factors. In addition, dietary strategies and the use of probiotics have been suggested as promising alternatives to prevent or mitigate the progression of these diseases. FINAL CONSIDERATIONS: The reviewed literature reinforces the importance of the gut-brain axis in the development of neurodegenerative diseases. Despite recent advances, further studies are still required to establish causal relationships and validate therapeutic interventions based on gut microbiota modulation. These findings may pave the way for new diagnostic and therapeutic strategies.