The vagus nerve and the gut. The game changer.
We are often told that our stress can impact our health, in particular our digestion. But what do we mean when we say it impacts it? How does it do it exactly?
The more you understand about the role that stress has within the body the better chances you will have at identifying it when it does occur and combatting it faster, so that it doesn't have long lasting effects on the body.
The vagus nerve is a cranial nerve reaching from the brain down the spine and innervating many different organs and systems within the body.
We often refer to the vagus nerves tone, is it is strong or weakened? Lowered vagal tone is linked with conditions such as inflammatory states, depression, poor mood regulation, poor cardiovascular health and conditions like irritable bowel syndrome and inflammatory bowel disease.
On a sub clinical level the vagus nerve can impact many areas of digestive health, all pot which contribute to symptoms such as reflux, GORD, bloating, IBS, changeable bowel motions and overall just not feeling 100%.
Lets start at the top and work our way down through the digestive system to get an idea of just how big of an influence the vagus nerds has on our gut.
Increased vagal tone has been linked with increased salivation. Saliva is the first stage of digestion, as it contains many digestive enzymes that immediately begin the digestive process, breaking down food. So relaxing and being present with your food is very important, this will help to stimulate the production of salivation independent of even tasting any food. (1)
In the stomach we want optimal stomach acid to help the breakdown of foods further. This helps to reduce symptoms of reflux or GORD, it encourages peristalsis (the movement of food through the digestive tract) and it helps to reduce bloating as the food will be broken down more effectively, making it easier for the gut to deal with when it gets to the small intestine.
The vagus nerve is involved in the production of hydrochloric acid (stomach acid) from the parietal cells in the stomach, so with low vagal tone this action can be reduced, and resulting in slower transit times for food (2) and an increased chance of bloating and conditions like SIBO to occur as it can have flow on effects and disrupt the gut microbiome.
As we mentioned above, the vagus nerve innervates many different organs within the body, and the liver happens to be one. The vagus nerve can have an influence on the bile duct as well, impacting the bodies capacity to produce bile. Bile is essential for optimal digestion as it helps us to breakdown and absorb fats from our foods. This can result in constipated conditions, reduced ability to digest foods that are high fat (good or bad fat) and even impact cholesterol levels as well.
When vagal tone is good, its our gut best friend. It actually helps to protect the gut wall from conditions like leaky gut (haven’t heard of leaky gut? Read all about it here), so without good vagus nerve activity this protection is diminished, making leaky gut more likely to occur. There have also been theories that this will also change the gut microbiome, results in digestive conditions like IBS, bloating etc but also other more systemic conditions such as mental health conditions, inflammatory conditions like arthritis and even hormonal imbalance. (3)
Have I scared you?
I hope not, because while all of this has the potential to happen, it just goes to show how interconnected everything is. So if we can make sure that vagus nerve tone is really good, then this will give all of the areas of digestion a fighting chance at functioning normally despite what else might be going on in your world.
So managing stress levels is so important for maintaining good vagus nerve tone and subsequently for maintaining good gut health as well.
Quick tip for supporting your vagus nerve:
Slow deep breathes. Slowing your breathing to 5-8 times per minute, in through the nose and out through the mouth. Do this when you’re in the car, watching TV, even while you’re working. This practice itself has so many other benefits like greater oxygenation of your cells as well as reducing cortisol levels within the body.
Karah is a degree qualified Naturopath with over 8 years experience in the health profession. She is the owner and director at The Sana Co and has a special clinical interest in digestive health, seeing many pateints with IBS, reflux/GORD, bloating and many otehr digetsive conditions.