Definition
The vagus nerve is a primary information highway between gut, heart, lungs, and brain. Roughly 80% of its fibers carry information from body to brain, not the other way around.
Why it matters
Vagal signaling clarifies that mood, safety, and digestion are constantly being negotiated between organs — not dictated top-down by the brain.
The Science
Vagal afferents relay information about gut distension, cytokines, microbial metabolites, and mechanical state. Efferent vagal fibers modulate motility, secretion, and inflammation (via the cholinergic anti-inflammatory pathway).
The NSI Perspective
NSI treats the vagus as one of the central nerves of Nervous System Intelligence — not a wellness slogan, but a documented signaling structure.
Clinical Implications
Interventions influencing vagal tone — slow breathing, meaningful connection, movement — are legitimate care with real physiological effects.
Practical Application
“Vagus” language has been oversold in marketing. The nerve is real; the practices that engage it are real; the miracle claims usually are not.
References
- 1.Bonaz B, Bazin T, Pellissier S. The vagus nerve at the interface of the microbiota–gut–brain axis. Front Neurosci. 2018;12:49.