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The Role of the Vagus Nerve in the Digestive System

Updated: Dec 15, 2023

The Vagus Nerve- The Most Important Nerve In The Digestive System

The vagus nerve is the longest and one of the most important nerves in the human body. It is a paired nerve, with one nerve on each side of the body, and it originates in the medulla oblongata, which is a part of the brainstem. This nerve has multiple branches that innervate various organs and structures in the body, including the heart, lungs, digestive system, and several other organs in the chest and abdomen.

The vagus nerve is a critical component of our immune system and plays a key role in maintaining homeostasis and regulation of many functions in our body. It is the only cranial nerve that connects the head and the brainstem through the neck all the way to the gut. It helps the digestive processes to function properly and regulates our parasympathetic nervous system (the one that is activated when we are relaxed).

Gastrointestinal function of the vagus nerve

The vagus nerve is actually a two-way communication system, it transmits information from the gut to the brain, and from the brain to the gut. It is responsible for the digestion process, immune system regulation and even mood regulation.

Have you ever wondered why we get the feeling of “butterflies in the stomach” when we are nervous? Or why does the term "listen to your gut" exist? There is a strong connection between our digestive system and our brain! In fact, studies show that 90% of serotonin - our “good mood” hormone - is not produced in our brain, but in our gut! Our vagus nerve plays a critical role in this function as well. This nerve is actually a kind of "antenna" that constantly receives messages from our body and monitors dangerous situations.

The vagus nerve controls various aspects of digestion, including stimulating the production of stomach acid and digestive enzymes, promoting peristalsis (the wavelike contractions of the digestive tract), and regulating the release of bile from the gallbladder.

Unfortunately, infections, inflammation and stress are among the leading factors that can weaken the vagus nerve.

Chronic stress is extremely damaging to the vagus nerve. When we are chronically stressed, the blood supply to the intestine is impaired, which also decreases the stimulation of the nerve. When the vagus nerve function is impaired, food does not break down properly, and undigested food particles activate the immune system in the gut, which causes inflammation and eventually can lead to leaky gut syndrome and other inflammatory conditions such as Inflammatory Bowel Disease (IBD)- Crohn's disease and Ulcerative colitis .

Dysfunction of the vagus nerve can also contribute to other gastrointestinal disorders such as gastroparesis (delayed stomach emptying) and Irritable Bowel Syndrome (IBS).

Other Functions of the Vagus Nerve

1. Parasympathetic Nervous System: The vagus nerve is a major component of the parasympathetic nervous system, which is responsible for the body's rest-and-digest response. It helps regulate various bodily functions such as heart rate, respiratory rate, digestion, and glandular secretions.

2. Heart Function: The vagus nerve plays a crucial role in regulating heart rate and cardiac function. It helps to slow down the heart rate and lower blood pressure during periods of rest and relaxation.

3. Respiratory Function: The vagus nerve influences the muscles in the throat and diaphragm that control breathing. It helps regulate the rhythm and depth of breathing.

4. Sensory and Motor Functions: The vagus nerve provides sensory information from the organs it innervates, such as the throat, heart, lungs, and digestive tract, to the brain. It also controls certain muscles in the throat and larynx that are involved in speech and swallowing.

How can we improve the functioning of our vagus nerve?

Stimulation of the vagus is a great way to improve its function and treat a wide variety of health problems, not only in the digestive system. Studies show that by stimulating the vagus nerve it is possible to treat health disorders such as epilepsy, depression, chronic pain and even sleep disorders.

One of the most effective ways that help the vagus nerve restore its normal activity is slow and deep breathing. Breathing is a therapeutic tool that improves the function of the nervous system and of the vagus nerve in particular.

Breathing as a tool to rehabilitate the vagus nerve

The amazing thing about breathing is that it is easy and simple and you can do it anywhere! There are many different types of breathing techniques. Most of them consist of a deep inhalation of the air through the nose, followed by a long exhalation of the air through the mouth. When we perform a long exhalation, the heart rate slows down and the blood pressure drops, this also relaxes our nervous system. Some techniques consist of holding the air in your lungs for a few seconds before exhaling. Other techniques work on activating the deep part of the throat, such as gargling, humming and singing.

In general, any calming and relaxation technique such as yoga, meditation and walking in nature would also benefit greatly to the proper functioning of the vagus nerve.

Vagus nerve
Vagus nerve


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