Your Gut Isn’t Working Alone: The Nervous System Connection to Gut Healing

10 minutes ago

5 min read

When we talk about healing the gut, we tend to focus first on food, and for good reason. What we eat, how much fiber we get, whether we are getting enough protein and nutrients, and whether certain foods are contributing to symptoms can all play an important role. Depending on the person, we may also need to look deeper at things like dysbiosis, bacterial overgrowth, infections, inflammation, digestive function or intestinal permeability.

But there is another piece of gut health that I think gets overlooked far too often: the nervous system.

You can be eating a nutrient-dense diet, taking all the “right” supplements and doing many of the things that support a healthy gut, but if your body is continually operating in a state of stress, digestion can be affected. This is where understanding the gut-brain axis, the vagus nerve and Polyvagal Theory can be really helpful.

The Gut-Brain Axis: Your Gut and Brain Are Constantly Communicating

The gut and brain are not two separate systems working independently of one another. They are in constant communication through what we call the gut-brain axis, a complex, two-way communication network involving the nervous system, immune system, hormones, gut microbes and the compounds those microbes produce.

Research continues to show just how interconnected these systems are. Signals originating in the brain can influence gastrointestinal motility, sensation and secretion, while signals originating in the gut can travel back to the brain through neural, immune, hormonal and microbial pathways.

This means that what is happening in the gut can influence the brain, mood and behavior, but communication also travels in the other direction. Stress and signals from the brain can influence how the digestive system functions, which helps explain why so many people notice changes in their digestion during particularly stressful periods of their lives.

One of the major communication pathways involved in this relationship is the vagus nerve, which connects the brain with many of our internal organs, including the digestive tract. The vagus nerve is an important part of the parasympathetic nervous system and participates in communication between the brain and gastrointestinal tract.

This is why I often remind clients that digestion doesn't begin with the first bite of food. Your nervous system is already helping set the stage for what happens when that food reaches your digestive tract.

Where Does Polyvagal Theory Fit In?

Polyvagal Theory was developed by neuroscientist Dr. Stephen Porges as a framework for understanding how our autonomic nervous system responds to safety, stress and perceived threat.

The basic idea is that our nervous system is continually gathering information from both inside and outside the body and responding accordingly, often without us consciously realizing it. In simple terms, your body is constantly responding to whether the environment feels safe or whether it needs to prepare for a challenge.

Polyvagal Theory describes several broad patterns of nervous-system response. When we feel safe and connected, what the theory refers to as the ventral vagal state, we tend to feel calmer, more present and more socially engaged. When the body perceives stress or danger, the sympathetic nervous system becomes more active, producing the familiar fight-or-flight response.

Polyvagal Theory also proposes a more immobilized or shutdown response, referred to as a dorsal vagal state, which may occur in response to overwhelming threat.

There is an important distinction to make here. Polyvagal Theory has become very popular as a way of understanding nervous-system responses, but some of its specific neurophysiological and evolutionary explanations remain scientifically debated. I find it helpful as a framework, but we don't need every aspect of Polyvagal Theory to be settled to appreciate something we know very clearly: the autonomic nervous system, stress response and digestive system are closely connected.

What Does Stress Have to Do With Your Gut?

Think about the difference between sitting down to a relaxed meal and trying to eat when you are extremely stressed. Maybe you're standing at the kitchen counter answering emails, eating lunch in your car between appointments or scrolling through stressful news while eating dinner. You may physically be putting food into your body, but your nervous system is still responding to everything happening around you.

Occasional stress isn't the problem. Our bodies are designed to respond to challenges and then recover. The concern is when stress becomes chronic and the body has fewer opportunities to return to a calmer, more restorative state.

Research has shown that both acute and chronic stress can influence gastrointestinal motor function, sensation and secretion through autonomic and neuroendocrine pathways. In real life, that means stress can contribute to changes in motility, appetite, bowel habits and how strongly we perceive sensations coming from the gut.

That doesn't mean digestive symptoms are “just stress,” and I think that distinction is incredibly important.

If someone is struggling with ongoing GI issues, we still need to investigate potential contributors such as H. pylori, dysbiosis, SIBO, pancreatic or gallbladder function, inflammation, food sensitivities and other underlying issues when appropriate.

But we also shouldn't ignore the environment in which digestion is taking place.

Supporting “Rest and Digest”

You've probably heard the expression “rest and digest.” This refers to the parasympathetic side of the autonomic nervous system and its important role in regulating gastrointestinal function.

This is why, when I work with someone on gut health, I don't only want to know what they are eating. I also want to know how they are eating and what the rest of their life looks like.

Are you sitting down for meals, or are you always eating on the run? Are you chewing your food well? Are you eating while working or answering emails? Are you sleeping enough? Are you exercising appropriately but also allowing your body to recover? Are you moving through your entire day feeling rushed and overwhelmed?

These may sound like simple questions, but they can be important pieces of the gut-health puzzle.

For example, I've written before about the relationship between stress, eating habits and stomach acid, because digestive function involves much more than simply what is on your plate.

Supporting the nervous system also doesn't need to become another complicated wellness routine. Taking a few slow breaths before eating, sitting down for meals, putting your phone away, chewing your food thoroughly, taking a walk outside, getting enough sleep, spending time with people you enjoy and simply creating moments during the day when you're not rushing can all help support the shift from constant stress toward rest and recovery.

Nutrition matters here too. There are foods and nutrients that support the gut microbiome and normal digestive function, which I discuss more in Gut-Friendly Nutrition: Supporting the Vagus Nerve for Optimal Digestion.

Gut Healing Is About the Whole Person

This is one of the things I love most about functional nutrition. We aren't simply asking, “What supplement should you take?” We're trying to understand why the body isn't functioning the way we want it to and what may be getting in the way.

Sometimes the answer involves food. Sometimes we need to look at the microbiome, blood sugar, digestive function, hormones, nutrient status or sleep. And sometimes chronic stress and nervous-system regulation are important pieces of that bigger picture.

Your gut and your brain are constantly talking to each other, so if we're trying to support one, we shouldn't forget about the other.

Healing the gut isn't just about what you eat or what supplements you take. It's about looking at the whole person and creating an environment that gives the body the support it needs to digest, recover and repair.