Depresión, ansiedad y microbiota intestinal: mecanismos neurobiológicos

Introduction: Gut dysbiosis has been recognized as a relevant factor in the etiology of neuropsychia-tric disorders such as depression and anxiety. Although the relationship between altered gut micro-biota and these disorders is well documented, the underlying molecular mechanisms remain incom-pletely understood. This study reviews recent literature to analyze the biological pathways that may explain this connection. Materials and methods: A narrative review of the available literature was conducted using biomedical databases, selecting studies that address the relationship between gut dysbiosis and affective disor-ders. The involved mechanisms were classified into three categories: the vagal pathway, intestinal permeability, and the effects of bacterial metabolites. Both animal and human studies were included. Results: The review identified that gut dysbiosis affects the central nervous system through three main mechanisms: the vagal pathway acts as a bridge between the gut microbiota and the brain, increased intestinal permeability allows the translocation of bacterial products, and bacterial metabolites such as lipopolysaccharides induce neuroinflammation and neurotransmission alterations. Discussion: The findings suggest that gut dysbiosis plays a critical role in modulating systemic and cerebral inflammation, contributing to the emergence of depressive and anxiety symptoms. Disruption of the intestinal barrier and the effects of bacterial metabolites are key elements in this relationship. Conclusions: Gut dysbiosis and alterations in the gut-brain axis are key determinants in the mani-festation of affective disorders, highlighting the potential of the microbiota as a therapeutic target in managing depression and anxiety.