Vagus Nerve and Underlying Impact on the Gut Microbiota-Brain Axis in Behavior and Neurodegenerative Diseases

Abstract

The gut microbiota is the most abundant and diverse microbiota in the human body and the vagus nerve is the most widely distributed and complex nerve in the body, both of them are essential in maintaining homeostasis. The most important phenomenon is how they coordinate to regulate functions, which has attracted the great attention of scientists. The academic literature on the correlation with a host of intestinal diseases and even systemic diseases has revealed the bidirectional communication between the gut microbiota and the brain, which can be carried out via multiple patterns. In the review, firstly, we have a general overview of the gut microbiota and the gut microbiota-brain axis. Secondly, according to the distribution characteristics of the vagus nerve, we analyzed and summarized its function in the intestinal tract. At the same time, we have summarized the underlying mechanism of some behavior changes such as depressive and anxiety-like behaviors and related neurodegenerative diseases caused by the vagus nerve and intestinal microecological environment disorders, and then we also analyzed inconsistency of the experimental evidence in order to propose novel strategies for the clinical practice.

Association of Pooled Fecal Microbiota on Height Growth in Children According to Enterotypes

“…The vagus nerve, the longest and most complex of the cranial nerves, serves as a major conduit for bidirectional communication between the gut and the brain, called the gut-brain axis (40). During the period of intestinal maturation in children, the vagus nerve plays a significant role in facilitating bidirectional communication between the developing gut and the brain (41). Recent research has indicated a significant link between certain gut bacteria and vagus nerve immaturation, leading to increased intestinal permeability in children (12).…”

Deciphering the intricate linkage between the gut microbiota and Alzheimer's disease: Elucidating mechanistic pathways promising therapeutic strategies

“…109 The VN consists of mainly afferent (80%) and efferent (20%) fibers, assumes a pivotal role in the transmission of signals between the brain and the intestinal tract. 109 The VN is the primary route for gut microbes to influence the brain, affecting metabolic and feeding behaviors, as well as inflammatory responses that link the brain, the gut, and other organs. 110 Enteroendocrine cells containing glucose-dependent insulinotropic peptide, glucagon-like peptide-1, and peptide YY can directly communicate with VN afferent fibers, which transmit information to the central autonomic network for analysis and integration, including the paraventricular nucleus, locus coeruleus, hypothalamus, and limbic system, such as the thalamus, amygdala, and hippocampus.…”

“…The VN consists of mainly afferent (80%) and efferent (20%) fibers, assumes a pivotal role in the transmission of signals between the brain and the intestinal tract 109 . The VN is the primary route for gut microbes to influence the brain, affecting metabolic and feeding behaviors, as well as inflammatory responses that link the brain, the gut, and other organs 110 .…”

A review on microbiota: relation with diseases and nutrients role

“…Attention deficit hyperactivity disorder (ADHD), cognitive development retardation, alterations in fear response, mood changes (depression and anxiety), and autistic spectrum disorder in children can all be caused by dysbiosis (Tanaka & Nakayama, 2017). The microbiota also plays a crucial role in activating the vagus nerve to transfer the information from the gastrointestinal tract to the nucleus tractus solitarius and help coordinate the body's function and regulate them (Han et al., 2022).…”