Gut Health
November 7, 2023
In recent years, our understanding of the human body's intricacies has deepened, shedding light on the remarkable connections between seemingly distinct bodily systems. One such revelation is the profound link between the vagus nerve and gut health. This relationship not only offers fascinating insights into our physiological functions but also has far-reaching implications for overall well-being. In this blog post, we'll explore the vagus nerve, its connection to the gut, and how nurturing this neural pathway can significantly impact our digestive health and beyond!
Are you here for it?
So…What Exactly is the Vagus Nerve?
The vagus nerve is a vital part of the autonomic nervous system, which consists of two different branches: the parasympathetic nervous system and the sympathetic nervous system. The parasympathetic system is the branch that allows “rest and digest” while the sympathetic system is the branch that manages our stress and “fight or flight” response by controlling heart rate [6].
The Vagus Nerve and Gut Health
The vagus nerve is the parasympathetic nervous system’s primary nerve that travels into many organs, including the heart, gut, and lungs. It is the longest nerve in the body, connecting the gut and the brain; it acts bidirectionally [2]. The nerve was coined “vagus,” which is Latin for “wandering” due to its extensive connections with different parts of the body and its effects on both physical and mental health [1].
The gut-brain communication system consists of several pathways, including a neurological pathway governed by the vagus nerve. Approximately 80% of this nerve flows from the body to the brain (afferent), while 20% of signals travel from the brain to the body (efferent).
The vagus afferents can sense gut bacteria within the gut microbiome through gut sensory cells, also known as neuropods. They transmit this information to the central nervous system through the fast neurotransmission of the neurons on the vagus nerve. Such activity is proportionally associated with overall health, well-being, relaxation, and emotions such as empathy [2].
As you can imagine, gut microbiome alterations and a lack of microbial diversity could affect the transmission of signals within the vagus nerve. The alteration of the gut microbiota alongside stress, infection, or poor diet could lead to a “leaky gut” and increased permeability in our intestinal barrier, which could result in inflammatory responses.
In some inflammatory conditions, the metabolism of specific amino acids, such as tryptophan, is shunted towards other pathways, reducing their availability for serotonin, a feel-good neurotransmitter.
Consequently, these alterations are common in neuropsychiatric disorders such as anxiety, depression, anorexia nervosa, and Alzheimer's disease [2]. What may come as surprising to many is that the food we eat may be contributing to the mental states we experience and the emotions we face. Fortunately, there are some foods and simple practices we can do to stimulate the vagus nerve for better mental and physical health!
Foods for Vagus Nerve Health
Although there haven’t been any direct studies that provide evidence regarding foods that affect the vagus nerve directly, many foods we eat could affect inflammatory markers and the neurotransmission of information. Such bodily responses are linked to the vagus nerve, affecting health and function. This is why it is important to eat foods that provide overall benefits to the body and, in turn, the vagus nerve.
1) Eat Foods Rich in Tryptophan [3]
The amino acid tryptophan is a precursor to serotonin, which is a mood-boosting neurotransmitter. Adding tryptophan-rich foods into our diet would increase its direct availability for serotonin. Tryptophan-rich foods include spinach, seeds, nuts, bananas, and poultry. Not only might these dietary changes contribute to serotonin, but some may also aid in managing gut inflammation, which could reduce gut leakiness.
2) Probiotics and Prebiotics [4,7]
Since gut bacteria affect our vagus nerve and our brain, it is vital to keep our microbiome diverse to improve our brain health. Probiotics are live bacteria that impart certain health benefits when consumed. Some examples of probiotics include kimchi, yogurt, miso, kefir, tempeh, and kombucha! Prebiotics are usually fibers that are fermented by the gut bacteria and aid in its health. Prebiotics include garlic, onions, chicory root, leeks, bananas, oats, and barley.
3) Omega 3-Fatty Acids [5]
Omega-3 fatty acids are anti-inflammatory fats for the body. Specifically, EPA and DHA omega-3 fatty acids are found in fish and may be linked to vagus nerve activity. Some fish rich in omega-3 fatty acids include salmon, oysters, herring, and sardines. Other foods include flaxseed, chia seeds, and walnuts.
Nurturing Your Vagus Nerve for Better Gut Health
Here are a few behaviors and techniques you can do to support vagus nerve function:
1) Breathing Exercises
Breathing is a behavioral form of vagal nerve stimulation that stimulates the vagus nerve bilaterally. Extending, slowing, and holding respiration are shown to activate the vagus nerve. Such maneuvers also play a role in slowing down the heart rate and inducing a sense of serenity [8].
2) Singing, Chanting, and Gargling
Chanting, singing, or gargling could help activate the vagus nerve [9]. Such activities lead to a vibration sensation, which helps stimulate the vagus nerve since it is connected to the back of the throat. A simple “Om” could also do the trick! Consequently, this could improve vagal tone.
3) Exercise
Mild to moderate exercise accelerates the gastric emptying rate in humans, consequently improving digestion. In response to mild exercise, the vagus nerve improves the ability of the stomach to digest food properly and efficiently [10]. Incorporating mild-medium exercise could help you alleviate the feeling of fullness. Strenuous exercise, such as high-intensity interval training (HIIT), might not have the same effect.
4) Meditation
There has been growing evidence that inflammation can be ameliorated by stimulating the vagus nerve. This could be achieved through the act of meditation and mindfulness. Meditation increases the vagal tone/stimulation and can lead to an influx of positive emotions [11]. You could also combine this with an “Om” at the end of your meditation to activate your vagus nerve even further! Lean into this practice. The people who struggle with meditation are usually the ones who need it the most.
Gut Health and Vagus Nerve: A Symbiotic Relationship
The vagus nerve plays a role in several different body systems; it plays a crucial role in the autonomic nervous system and the gut-brain connection. Its full range of functions remains to be elucidated. We should strive to improve our vagus nerve health and promote healthy habits to strengthen it, especially when there is a history of trauma. While more research is needed to uncover additional mechanisms, our evidence is strong enough to advocate for prioritizing vagal tone.
If you’ve been experiencing ongoing issues, please don’t hesitate to seek help from professionals or people around you; there are many options today! Wise Mind Nutrition is another helpful resource, as we aim to provide you with further research linking gut, brain, and nervous system health. The healing awaits you.
Blog Contributor:
AlAnoud Dabbas
References:
Food For the Brain Foundation. Key ways to support healthy vagus nerve function [Internet]. Food for the Brain. 2020 [cited 2023 Oct 31].
Mörkl S, Butler MI, Wagner-Skacel J, Gut-brain-crosstalk the vagus nerve and the microbiota-gut-brain axis in depression. A narrative review, Journal of Affective Disorders Reports. 2023; 13.
Vagus nerve stimulation and function for better gut and mental health [Internet]. The Health Space | Certified Nutritionist. 2023 [cited 2023 Oct 31].
Robertson, R. 9 Ways to Improve Your Gut Bacteria, Based on Science [Internet]. Healthline, Healthline Media. 2023 [cited 2023 Oct 31].
Garr, S. The Vagus Nerve Explained in Plain English [Internet]. Diet vs Disease, Diet vs Disease. 2023 [cited on 2023 Oct 31].
Gerritsen RJS, Band GPH. Breath of Life: The Respiratory Vagal Stimulation Model of Contemplative Activity. Front Hum Neurosci. 2018;12:397.
Bravo JA, Forsythe P, Chew MV, et al. Ingestion of Lactobacillus strain regulates emotional behavior and central GABA receptor expression in a mouse via the vagus nerve. Proceedings of the national academy of sciences of the United States of America 2011;108(38):16050–16055.
Gerritsen RJS, Band GPH. Breath of Life: The Respiratory Vagal Stimulation Model of Contemplative Activity. Front Hum Neurosci. 2018; 12:397.
Kalyani BG, Venkatasubramanian G, Arasappa R, Rao NP, Kalmady SV, Behere RV, Rao H, Vasudev MK, Gangadhar BN. Neurohemodynamic correlates of 'OM' chanting: A pilot functional magnetic resonance imaging study. Int J Yoga. 2011; 4(1):3-6.
Wang Y, Kondo T, Suzukamo Y, Oouchida Y, Izumi S. Vagal nerve regulation is essential for the increase in gastric motility in response to mild exercise. Tohoku J Exp Med. 2010; 222(2):155-63.
Bergland C. Vagus Nerve Stimulation Dramatically Reduces Inflammation. Psychology Today. 2016.
