The Power of Psychobiotics in Depression: A Modern Approach through the Microbiota–Gut–Brain Axis: A Literature Review

Abstract

The microbiota–gut–brain (MGB) axis is a complex communication network linking the gut, microbiota, and brain, influencing various aspects of health and disease. Dysbiosis, a disturbance in the gut microbiome equilibrium, can significantly impact the MGB axis, leading to alterations in microbial composition and function. Emerging evidence highlights the connection between microbiota alterations and neurological and psychiatric disorders, including depression. This review explores the potential of psychobiotics in managing depressive disorders, emphasizing their role in restoring microbial balance and influencing the MGB axis. Psychobiotics exhibit positive effects on the intestinal barrier, immune response, cortisol levels, and the hypothalamic–pituitary–adrenal (HPA) axis. Studies suggest that probiotics may serve as an adjunct therapy for depression, especially in treatment-resistant cases. This review discusses key findings from studies on psychobiotics interventions, emphasizing their impact on the gut–brain axis and mental health. The increasing acceptance of the expanded concept of the MGB axis underscores the importance of microorganisms in mental well-being. As our understanding of the microbiome’s role in health and disease grows, probiotics emerge as promising agents for addressing mental health issues, providing new avenues for therapeutic interventions in depressive disorders.

Baseline gut microbiota profiles affect treatment response in patients with depression

“…Numerous studies have observed two-way communication between the microbiota and the brain ( Kunugi, 2021 ; Sharma et al, 2021 ; Trzeciak and Herbet, 2021 ; Ye et al, 2021 ; Hou et al, 2022 ; Dziedzic et al, 2024 ) through the gut–brain axis, which encompasses multiple components, including the CNS, spinal cord, autonomic nervous system, enteric nervous system, immune system, and hypothalamic–pituitary–adrenal axis ( Carabotti et al, 2015 ). The gut microbiota can produce various molecules that act at distal sites to imitate the function of endocrine organs ( Tsigos et al, 2000 ; Clarke et al, 2014 ), such as short-chain fatty acids (SCFAs), neurotransmitters (including serotonin, dopamine, norepinephrine, and γ-aminobutyric acid), cholic acids, tryptophan, L-dopa, adipokines, and hormones ( Clarke et al, 2014 ).…”