Do the Brain and Gut Really Communicate?
By Kelsey Chadwick, MS RDN
August 4th, 2025
Gut-health… digestive health…prebiotics… probiotics…
You’ve probably heard all the buzzwords. But today, let’s zoom in on one of the most fascinating topics in the world of gut health: the gut-brain connection, also known as the gut-brain axis.
For thousands of years we have known that the brain and gut communicate (think hunger and fullness cues). However, it wasn’t until fairly recently that we learned that communication between the brain and the gut is bidirectional and utilizes neural pathways, not just hormone signaling. Neural pathways are routes for communication between different neurons (nerve cells) in the brain. These neurons or nerve cells are responsible for sending messages throughout the body so we can breath, talk, walk, think and even eat.
Let’s break it down a bit. I promise to keep the science digestible (pun intended!).
So, What Is the Nervous System Doing Here?
Your nervous system has two main parts:
Central nervous system (CNS) – your brain and spinal cord.
Peripheral nervous system (PNS) – everything else branching out from the CNS.
The PNS is further divided into:
Somatic nervous system – handles voluntary actions (like waving your hand).
Autonomic nervous system – runs the background stuff, like breathing, digestion, and your heartbeat. This is where you’ll often hear descriptions of the difference between “rest and digest” versus “fight or flight” states of the nervous system.
The autonomic nervous system is where we find the enteric nervous system (ENS)—a.k.a. your gut’s very own nervous system! Think of it as your "second brain."
The Gut’s Own Nervous System (Yep, It Has One)
The ENS is made up of millions of neurons and has two main networks:
Submucosal plexus – manages secretions and absorption.
Myenteric plexus – controls movement and muscle contractions in digestion.
Cool fact: the ENS produces dopamine, serotonin, and acetylcholine—important brain chemicals that affect both your mood and how your body feels.
Enter: The Vagus Nerve
Meet the vagus nerve—a superstar in this story. It runs from your brain to your gut and helps control digestion, mood, immune response, and heart rate. Deep, slow breathing can actually stimulate the vagus nerve, activating that calming “rest and digest” mode. Pretty amazing, right?
Here is a great visual that describes the Gut-Brain Axis:
Image from Mind Your Gut
Quick Recap: What to Know About the Gut-Brain Connection
The brain and gut communicate in both directions
The central nervous system AND enteric nervous system AKA “gut nervous system” produces important chemicals that play a big role in how we physically and emotionally feel
The vagus nerve helps manage digestion and mood
We have a lot more to learn about the gut-brain connection and digestive disorders!
Sources
The Microbiota-Gut-Brain Axis: From Motility to Mood
Margolis, Kara G. et al.
Gastroenterology, Volume 160, Issue 5, 1486 - 1501Scarlata, Kate, et al. Mind Your Gut: The Science-Based, Whole-Body Guide to Living Well with IBS. Hachette Go, 2024.
https://www.ninds.nih.gov/health-information/public-education/brain-basics/brain-basics-life-and-death-neuron#:~:text=Neurons%20are%20nerve%20cells%20that,were%20ever%20going%20to%20have.