The vagus nerve has 80% of its branches in the parasympathetic nervous system, our rest and digest system. To have optimal digestion, we have to be in a calm & safe state in our nervous system. Optimal vagus function drives digestion, assimilation and elimination. If someone is hardwired to chronic stress, in trauma response and in a masculine flow state, this effects the gut and leads to poor gastric motility and enzyme activity. This ultimately manifests into physical issues such as constipation, IBS, nausea, poor appetite (adrenal glands control hunger eg cortisol is an appetite suppressant), gas, bloating, Crohns, GERD, diarrhoea

Here are some ways the vagus nerve is involved in the digestion system:

➡️ It Upregulates the Breakdown of Solids
The vagus upregulates the mechanical breakdown of solid food. It signals the stomach to churn the food within it, as well as to produce stomach acid that’s necessary for digesting that food. This is why a low tone, damaged or under-active vagus nerve often results in low stomach acid levels & low enzyme production. Being able to break down our food before it enters the digestive tract is important. Otherwise, we can have a whole host of symptoms from reflux, to bloating, to flatulence (gas).

➡️ It Stimulates the Secretion of Saliva 
When food enters our mouth, we have our salivary glands that release salivary enzymes. This helps to break down the food before it enters the esophagus. Vagal afferent stimulation significantly increases the salivation & swallowing process. It controls saliva production, both the volume and type of saliva we secrete

➡️ It Stimulates the Release of Digestive Enzymes and Bile
The vagus nerve stimulates your digestive enzymes coming from the pancreas as well as bile from the liver. These are very important in breaking down the food appropriately so it can continue to pass from the esophagus to the stomach, small intestine and large intestine to be ultimately excreted.

➡️ It Allows for the Accommodation of Food in the Stomach
Optimal vagal tone signals the production of hydrochloric acid & pepsin which helps to break down food even further, especially proteins.

➡️It Slows Gastric Emptying
Slow emptying of food makes sure we are receiving proper absorption of nutrients from the food we ingest

➡️It Coordinates the Motility of Intestines
When food comes into the small intestine for absorption of nutrients, it has to pass through to the large intestine & be excreted via the rectum. The migrating motor complex in the small intestine creates a wave-like action to help move the food through to the large intestine. This functioning is dependent on the function on the vagus nerve

➡️It Decreases Inflammation andIntestinal Permeability (leaky gut)
When the function of the vagus nerve is low and we do not have proper motility & proper assimilation of nutrients, these tight junctions in the epithelial lining of the gut lose their integrity. This allows pathogens, toxins, undigested food and bacteria to move through the bloodstream, which effects the immune system and causes an inflammatory response in the NS.

➡️It Increases Satiety
If you have optimal vagus nerve function, you’ll be able to easily feel the cues for hunger & recognise when you’re full. When you have low vagal tone, it is generally difficult to determine. You may eat too much or not enough. This is a huge variability in weight fluctuations, weight loss and overall health

The vagus nerve passes signals and information back and forth between the brain and the gut. Gut bacteria produces 90% of our serotonin levels, a neural hormone that influences our mood, sleep, digestion, wound healing, bone health, blood clotting, sexual desire and libido levels. This is all informed by the health of the vagus nerve.

The state of your vagus nerve, and therefore your parasympathetic nervous system, impacts your gut function and digestive system. the nerve innervates the entire digestive tract. If you’re experiencing chronic stress, low vagal tone, frustration, anger, worry, anxiety, or you’re in a freeze state (dorsal shut down), your gut health will be deeply affected and this can give rise to issues such as low microbiome, leaky gut, inability to absorb nutrients, IBS, to name a few.

To improve your gut health, you will need to improve your vagus nerve function.