AUTHOR=Tan Chaoren , Yan Qiqi , Ma Yue , Fang Jiliang , Yang Yongsheng 

TITLE=Recognizing the role of the vagus nerve in depression from microbiota-gut brain axis

JOURNAL=Frontiers in Neurology

VOLUME=Volume 13 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2022.1015175

DOI=10.3389/fneur.2022.1015175

ISSN=1664-2295

ABSTRACT=Depression is a worldwide disease causing severe disability, morbidity, and mortality. Despite abundant studies, the precise mechanisms underlying the pathophysiology of depression remain elusive. Recently, cumulate researches suggest that a disturbance of microbiota-gut-brain axis may play a vital role in the etiology of depression while correcting this disturbance could alleviate depression symptoms. The vagus nerve, linking brain and gut through its afferent and efferent branches, is a critical route in the bidirectional communication of this axis. Directly or indirectly, the vagus afferent fibers can sense and relay gut microbiota signals to the brain and induce brain disorders including depression. Also, brain changes in response to stress may result in gut hyperpermeability and inflammation mediating by the vagal efferents, which may be detrimental to depression. Notably, vagus nerve stimulation owns an anti-inflammatory effect and was proved for depression treatment. Nevertheless, depressive disorders were accompanied by a low vagal tone, which may derive from response to stress and contribute to pathogenesis of depression. In this review, we aim to explore the role of vagus nerve in depression from the perspective of microbiota-gut-brain axis, highlighting relationship among the vagal tone, the gut hyperpermeability, inflammation and depression.