Relação existente entre a microbiota intestinal e a depressão

Abstract

Gut microbiota or gut flora corresponds to a complex of species of microorganisms that lives in the digestive tract of animals. In humans, this microbiota has the following functions: digestion, nutrient production, regulation of the immune response against pathogens, influence and interference in the brain-gut axis. This last function contributes to the proper functioning of the central nervous system (CNS), which makes the connection of the brain pathways and gastrointestinal system very important for organic homeostasis. The composition of the human microbiota is determined by a series of factors that can lead, at times, to deviations from the functions of the microbiota and consequently to disrupt the bidirectional communication between the gut and the CNS. The action of microbial metabolites, such as short-chain fatty acids (SCFAs), neurotransmitters, and the role of the vagus nerve are forms of interaction between the microbiota-gut-brain axis. These deviated actions due to functional maladjustments of the axis demand the emergence of intestinal dysbiosis that can lead to the development of neuroinflammation, enabling the emergence of neuropsychic diseases, such as depression. Clarifying and exploring the relationship between the gut microbiota and depression is the objective of this study, through a narrative review with a qualitative approach through bibliographic and electronic sources. It is concluded that despite few articles involving human beings, it is verified that the relationship between intestinal microbiota and depression exists considerably, being justified by several interferences involving the production of cytokines, neurotransmitters and intestinal permeability. Therefore, the modulation of the gut microbiota creates a new perspective on the pathophysiology, prevention, and treatment of depression. The results showed that the relationship between gut microbiota and depression is pertinent, despite the small number of articles related to the human species. It is concluded that the relationship between gut microbiota and depression is considerable, being justified by several interferences involving cytokine production, neurotransmitters, and intestinal permeability. Therefore, the modulation of the gut microbiota creates a new perspective on the pathophysiology, prevention, and treatment of depression.