A review of current concepts of the bidirectional gut-brain axis in the pathogenesis of depressive disorders

This work focuses on the current definitions of the role of the intestinal microbiota in the development of depressive disorders in patients with chronic somatic pathology. The relevance of this issue is related to the high prevalence of depression and its comorbidity with somatic pathology. This makes it difficult to find effective and convenient treatment regimens. The solution to this problem may be related to scientific research in the field of the pathophysiology of depression. According to modern views, the pathophysiology of depression is not limited to serotonin metabolism. There are points of contact and intersection with the pathology of the immune system in the context of the development of chronic inflammation. The development of depression is also influenced by the effectiveness of communication between the central nervous system and the human microbiome, particularly the gut microbiota. The influence of the gut-brain axis on the pathogenesis of depression is a promising area for finding new therapeutic targets in the treatment of severe comorbid patients. The relationship between the gut microbiota and the central nervous system is bidirectional and multifactorial. To develop new personalized therapeutic schemes using all options for influencing intestinal microorganisms (prebiotics, probiotics, synbiotics, and intestinal microbiota transplantation), a more precise understanding of the cause-and-effect relationships in the gut-brain axis is necessary. The article provides an overview of recent research on the main pathways of mutual influence between the intestinal microbiota and the central nervous system in the context of the pathogenesis of depressive disorders and the possibility of iatrogenic effects on them.