Your Stomach Has a Second Brain — And It's Talking to You

I was a young adult sitting in a circle of friends — talking, laughing, having a good time. But I didn't feel good. My stomach hurt badly, the pain racing around my side and up into my back. I tried to discreetly lean forward instead of doubling over as I wanted to. I was miserable.

It turned out to be a bad case of indigestion. I'm sure you can relate. What was baffling at the time was the why behind it. It recurred numerous times with no definitive explanation. Looking back, I now suspect it stemmed from anxiety.

But which came first — the anxiety causing the heartburn, or the heartburn causing the anxiety?

The Gut-Brain Connection

The gut houses your enteric nervous system, sometimes called the "second brain." Some experts consider it our primary brain, given the extensive neuronal activity within it. This network of neurons responds to your external and internal environment and establishes a felt sense of safety or danger.

If someone cuts you off in traffic, or you hear a sound associated with past harm, your nervous system immediately signals that your environment is unsafe. Even if the threat resolves in an instant, your body will remain in fight-or-flight mode until safety is re-established.

When past stress or trauma has never been fully processed, the body creates new nervous system patterns to compensate — resulting in a state of hypervigilance. You may not even recognize how tense you've become until something magnifies it: your heart races, your stomach aches, digestion goes haywire. Anxiety is having a direct impact on your gut.

The same dynamic works in reverse. A gut infection or chronic inflammation signals danger to your immune system and brain. If that internal environment remains chronically compromised — think yeast, bacterial overgrowth, H. pylori, parasites, leaky gut, IBS, acid reflux, or chronic constipation and diarrhea — your digestive system gets stuck in a state of dysfunction, keeping your body on high alert and feeding anxious feelings every time your stomach acts up.

The Vagus Nerve: The Bridge Between Both

It's difficult to say which comes first — digestive issues or anxiety. But the connecting thread is the vagus nerve. Stimulating it can calm both your digestive tract and your anxious feelings simultaneously.

That said, stimulating the vagus nerve isn't a substitute for addressing the root causes — whether that's unresolved stress in your external environment or chronic compromise in your gut. Both need attention as part of a full healing process.

The key is not to isolate one from the other. They influence each other, and lasting relief comes from addressing that connection.

A Practical Order of Support

1. Learn vagus nerve exercises. Body-based practices can stimulate the vagus nerve in just minutes, signaling safety to your nervous system and shifting your body from crisis mode toward healing.
2. Establish rhythm and routine. Consistent eating and sleeping schedules, time away from screens, and regular walks — ideally outside — give your body a dependable rhythm it can feel safe within.
3. Investigate what's happening internally. A stool test or comprehensive blood work can reveal what needs targeted support. Many people want to jump straight to this step, but without the foundation of safety established in steps one and two, the body often struggles to respond and heal.

Your body was designed to prioritize survival and to help you thrive. When it speaks to you through anxiety or digestive discomfort, listen — and remember how interconnected those signals are. Establish a sense of safety first, then look for the root.