The vagus nerve is the superhighway of the gut-brain axis. Understanding how to activate it could be the missing piece in your healing journey.
The vagus nerve is the longest cranial nerve in the body, running from the brainstem all the way down to the abdomen. It carries information in both directions — from the brain to the gut and from the gut to the brain — making it the primary communication channel of the gut-brain axis.
About 80% of vagal fibers are afferent, meaning they carry signals from the gut to the brain. This means your gut is constantly sending information to your brain about the state of your microbiome, inflammation levels, and digestive function.
Vagal tone refers to the activity level of the vagus nerve. High vagal tone is associated with better digestion, lower inflammation, improved mood, and greater resilience to stress. Low vagal tone is linked to IBS, depression, anxiety, and inflammatory conditions.
How to stimulate the vagus nerve: Deep diaphragmatic breathing is one of the most powerful vagal activators. Slow, deep breaths — particularly with a longer exhale — activate the parasympathetic nervous system and increase vagal tone.
Cold exposure, humming, gargling, and singing also stimulate the vagus nerve through its branches in the throat and ear. Even a few minutes of these practices daily can meaningfully improve vagal tone over time.
Probiotics have been shown to communicate with the brain via the vagus nerve. Specific strains — particularly Lactobacillus rhamnosus — have demonstrated anti-anxiety effects that are abolished when the vagus nerve is severed, confirming the gut-brain-vagus connection.
In my practice, vagal nerve support is a foundational component of gut healing protocols. When the nervous system is in a chronic state of fight-or-flight, digestive healing is nearly impossible. Restoring vagal tone creates the physiological conditions for true gut repair.
Dr. Teresa Rispoli
PhD., ND, LAc. — Functional Medicine & Nutrition