Gut microbiota in anxiety and depression: mechanisms, drug interactions, and therapeutic implications

Anxiety and depressive disorders constitute a public health concern with a high negative impact on patients' quality of life. These disorders are among the prevalent neuropsychiatric conditions significantly contributing to the global burden. Although the precise mechanisms underlying the development of anxiety- and depressive-like behaviors remain incompletely understood, increasing evidence indicates that these disorders arise from complex and multifactorial processes involving dysfunction across multiple body organs. The gut microbiota (GM) seem to play certain role in developing of these conditions, as supported by studies demonstrating its influence on brain function and behavior. Indeed, several studies have recently reported that alterations in GM composition and function are linked with immune system dysregulation (inflammation/neuroinflammation) and subsequently influence brain pathways and systems, including neurotransmitters, the hypothalamic-pituitary-adrenal axis (HPA), and neurotrophic factors. Also, therapeutic agents targeting gut dysbiosis (GD) have yielded significant results. This review summarizes the role of GM in the pathophysiology of anxiety and depressive behaviors, its interaction with some psychotropic drugs, and its potential use as a therapeutic target for these conditions.Clinical trial number: Not applicable.