Have you heard of the Vagus nerve? How about the gut-brain axis? Ever wonder how your brain knows you are hungry? Ever wonder why your gut starts to cramp when you are stressed or worried about something? A good way to explain this communication is the idea of the parasympathetic nervous system and the bridge it creates between your gut and your brains.
Please keep in mind, this is just a general description of the vagus nerve and the role it plays particularly in digestion within your body. There are so many more roles this system has, and is really so much more awesome than the impression I give here! Even just general google searches online will give you plenty of information on how this nerve maintains our homeostasis.
The Vagus nerve is a group of nerve fibres stemming from the medulla section of the brain, running down the pharynx and larynx (near the esophagus) and the spine, all the while connecting to the lungs, heart and the digestive system. These nerves carry motor and sensory signals or impulses to and from the digestive system and the brain stem. This group of nerves make up 80% of the parasympathetic nervous system (PNS), which is also known as the rest-or-digest system. Therefore, these nerve fibers not only have a role in promoting digestive activity, but also helps regulate your heart activity. The vagus nerve however, is only part of a greater system that runs from the GI tract to the brain, called the gut-brain axis.
The broader system that is the gut-brain axis is what connects our emotional feelings and cognitive function with the digestive functions of our gut. I STILL think this is amazing! As I was growing up, and even into my 20’s, I just thought of the brain as a completely different ‘department’ from the gastrointestinal tract. Our intestines digest food, and our brains help us learn, avoid danger and connect with others. What possible reason could there be for our brains to connect directly to our guts? Our guts don’t need brains! Boy, how wrong was I!
This nerve, in its responsibility of connecting the brain and the GI tract, plays an important role for helping the gut fight inflammation. Mostly though, it helps conduct the contraction and relaxation of the muscles in the intestinal wall, which play a role in successful digestion of your stool. This nerve also helps instigate the release of digestive enzymes, which are responsible for helping break down the food and facilitate the absorption of the nutrients into the blood stream. These fibers also help regulate reflex actions in swallowing, coughing, or vomiting
However, the most significant role of this nerve is the transfer of information from the digestive system, assorted organs, heart and lungs towards the brain. These nerves communicate warnings of inflammation, satiety (hunger and feeling full) as well as the metabolism of energy to the brain. Within this maze of nerve fibers, is the participation of activation and regulation of the HPA axis, and helps our organisms become familiar with stressors that our body encounters. It is said that these nerves can also be influenced by the gut microbiome, which is the overall colony balance of gut bacteria that exist in our digestive system. When the nerve fibers belonging to the vagus nerve are influenced or triggered by the gut bacteria, these certain signals can and will affect the brain and how it perceives stress, and even impending danger.
What does this mean? It means that our gut bacteria has significant influence on our anxiety and even depression. There are numerous studies on this very idea, and I have included one study below that is very interesting!
This means that the vagus nerve plays an important role in conducting our behaviour. So could the consumption of specific nutrition help influence mental health? Definitely! There are numerous articles and studies that state that the consumption of probiotics, antibiotics, and even gluten, when interacting with present gut bacteria, have significant influence on the signals sent to the brain within the vagus nerve, and therefore can influence our behaviour.
The effectiveness in the transfer of these signals is termed VAGAL TONE, and there are a few easy ways to improve this network of nerves, and create a much healthier mental state, metabolic state, heart rate and essentially blood flow.
There is a great resource online, that I will include the link to below, that explains vagal tone and how to influence it. If the vagal tone is high, organs such as the heart and lungs are performing normally, and we have a good mental well-being. But if the vagal tone is low, this is where dysfunction occurs, heart disease, inflammation, declining mental health, higher anxiety, etc. One excellent way to improve tone is yoga, as it naturally works with our pace of breath.
But there are also certain yoga practices and poses that open up the heart chakra such as camel pose or even cat/cow pose which also flexes the spine, which is where the vagus nerve runs.However, if you read the article included below, there are numerous other methods to practice, such as cold exposure & massage, and internal factors including singing or chanting, slow breathing and meditation. Basically, these are all ways to calm ourselves down, and lower anxiety.
So, that kind of explains why certain practices such as deep and slow breathing, meditation and yoga can help calm us down. When we stimulate the vagus nerve, it allows better communication between the brain and assorted organs in our body. However, this can only be so effective if there is unhealthy bacteria in your gut, which as I stated above, influences the performance of information transfer to the brain. This shows how an unhealthy diet can influence our mental health and anxiety levels negatively. If you consume unhealthy food that will most definitely imbalance gut bacteria levels (good & bad), then it will inevitably affect your mood and stress levels. But, this isn’t a dead end street! The good thing about our gut microbiome is that, if treated properly, can always be adjusted and corrected with proper food and supplement nutrient intake. A healthy gut means a healthy mind!