Gut Health Is Mental Health
The Vagus Nerve, Your Brain, and Why Fixing the Gut Changes Everything
We’ve been taught that mental health lives in the brain.
But your brain is constantly taking cues from somewhere else first.
Your gut.
There’s a direct communication highway between the gut and the brain called the vagus nerve — and it runs from your brainstem down into your digestive tract.
It’s anatomy.
And it changes how we should think about anxiety, mood swings, inflammation, and stress.
What Is the Vagus Nerve, Really?
The Vagus nerve is a real, physical nerve, Cranial Nerve X, and it is one of the longest nerves in the human body.
It begins in the brainstem (medulla oblongata), exits at the base of the skull, and travels down through:
• The neck
• The chest
• The heart
• The lungs
• The esophagus
• The stomach
• The small intestine
• Part of the large intestine
It is literal wiring between your brain and your digestive system.
And here’s the part most people don’t know:
About 80% of its fibers send information from the body back up to the brain.
That means your brain is constantly receiving updates from your gut.
If the gut is inflamed → the brain is signaled.
If digestion is sluggish → the brain is signaled.
If stress is high → vagus nerve tone decreases.
This is why anxiety often feels like it starts in your stomach.
It’s neurological.
The Gut–Brain Connection
Your gut and brain are constantly communicating through:
• The vagus nerve
• Neurotransmitters
• Immune signals
• Inflammatory markers
• Hormones
Nearly 90% of serotonin is produced in the gut.
When the gut is irritated or inflamed, that signal travels up the vagus nerve to the brain, influencing mood, focus, and stress sensitivity.
The Gut–Brain Connection
Your gut and brain are constantly communicating through:
• The vagus nerve
• Neurotransmitters
• Immune signals
• Inflammatory markers
• Hormones
In fact:
Nearly 90% of serotonin (your “feel good” neurotransmitter) is produced in the gut.
When the gut is inflamed, irritated, or imbalanced… that signal travels up the vagus nerve to the brain.
The brain responds with:
• Anxiety
• Brain fog
• Mood swings
• Fatigue
• Irritability
• Stress sensitivity
This is why you can “feel it in your stomach” when you're anxious.
It’s neurological.
What Damages the Gut–Brain Connection?
Chronic stress
Processed foods
Blood sugar spikes
Alcohol
Lack of sleep
Inflammation
Antibiotic overuse
Stress alone can:
• Reduce stomach acid
• Slow digestion
• Alter gut bacteria
• Increase intestinal permeability
When digestion is off, inflammation rises.
When inflammation rises, mental health often declines.
The Vagus Nerve: Your Built-In Calm Switch
The vagus nerve is part of your parasympathetic nervous system, your “rest and digest” mode.
When it’s functioning well:
• Digestion improves
• Heart rate lowers
• Cortisol stabilizes
• Mood steadies
• Inflammation decreases
When it’s underactive:
• Anxiety increases
• Digestion weakens
• Stress stays elevated
• Sleep suffers
Supporting the vagus nerve helps support the gut.
Supporting the gut helps support the brain.
How to Soothe the Gut–Brain Connection
It requires consistency.
1️⃣ Eat for gut stability
Focus on:
• Whole foods
• Fiber from vegetables
• Fermented foods (if tolerated)
• Protein for blood sugar stability
• Healthy fats
Reduce:
• Ultra-processed foods
• Refined sugar
• Seed oil overload
• Constant snacking
Stable blood sugar = calmer nervous system.
2️⃣ Slow down while eating
If you eat in stress mode, digestion weakens.
Try:
• Sitting down
• Chewing thoroughly
• No phone scrolling
• A few deep breaths before eating
You cannot digest well in fight-or-flight.
3️⃣ Humming (Yes, really)
Humming stimulates the vagus nerve.
The vibration in the throat activates it.
Singing, chanting, and even gargling have similar effects.
It’s simple. It works.
4️⃣ Meditation & Breathwork
Slow nasal breathing
Long exhales
Guided meditation
Prayer
These shift the nervous system from fight-or-flight into rest-and-digest.
When digestion improves, mood often follows.
5️⃣ Sunlight + Movement
Light exposure regulates circadian rhythm.
Circadian rhythm regulates digestion.
Movement improves gut motility.
Even 10–20 minutes outside matters.
The Bigger Picture
You can take all the supplements in the world.
But if the nervous system is dysregulated, digestion will struggle.
And if digestion struggles, inflammation rises.
And when inflammation rises, mental health often declines.
Fixing the gut isn’t just about bloating.
It’s about:
Mood
Focus
Energy
Stress tolerance
Sleep
Hormone balance
The gut is not separate from the brain.
It talks to it all day long.
If you want a calmer mind, start by calming the gut.
Sometimes the most powerful mental health support isn’t a pill.
It’s a nervous system that feels safe.