"A Feeling in my Gut"
By: Lior Zweig, '18
(CHAOS 2017 EDITION)
(CHAOS 2017 EDITION)
The human brain is notoriously the most complex part of the human body. It serves as the center of your nervous system, sending billions of electrical signals every moment to control your mood, speech, and thoughts. What if there were another part of you that could control your mood levels, your anxiety, and your depression? What if it were a part of you that you could actively control and maintain?
The vagus nerve connects the human brain to the heart, lungs, and gut. This nerve is related to your fight or flight mechanism; the knot in your stomach that many people get when they are upset. This is because roughly 80% of nerve signals go from the digestive tract to the brain, telling us how to feel or what to think. Around 90% of human cells are bacterial, outnumbering human genes from 99 to 1. This bacteria was acquired overtime based on factors such as the human diet, a mother’s vaginal microbes, to kisses from a family member.
In a study led by John Cryan, a neuroscientist at University of Cork in Ireland, it was concluded that anxious mice dosed with the probiotic bacterium Lactobacillus rhamnosus (JB-1) revealed lower anxiety, decreased cortisol and other stress hormones, and even an increase in brain receptors for a neurotransmitters characteristic to curbing negative feelings such as fear and anxiety.
A study in 2011 from McMaster University tested the behaviors of normal 8 week old mice compared to 8 week old mice stripped of their gut microbiomes. Those not containing bacteria illustrated higher cortisol (stress) and depression rates, altering the level of BDNF in the brain, which plays a large role in mood regulation. Researchers from McMaster University also transplanted microbiomes from groups of timid mice with groups of outgoing mice. The outgoing mice became more timid when stripped of their normal bacteria, and vice versa.
The nerves that line the digestive tract from the esophagus to the anus, called the enteric nervous system, do not even require the brain at all, because when the vagus nerve is broken the enteric nervous system can still continue digestion due to the complexity of its neurons. The gut and the brain are connected for a time back when humans needed to know what kind of food to eat in order to detect what is most beneficial for survival, as it tells the brain to release dopamine when we eat palatable foods high in fats/sugars. The microbes in your gut however, produce 50% of your dopamine and 90% of your serotonin.
The vagus nerve connects the human brain to the heart, lungs, and gut. This nerve is related to your fight or flight mechanism; the knot in your stomach that many people get when they are upset. This is because roughly 80% of nerve signals go from the digestive tract to the brain, telling us how to feel or what to think. Around 90% of human cells are bacterial, outnumbering human genes from 99 to 1. This bacteria was acquired overtime based on factors such as the human diet, a mother’s vaginal microbes, to kisses from a family member.
In a study led by John Cryan, a neuroscientist at University of Cork in Ireland, it was concluded that anxious mice dosed with the probiotic bacterium Lactobacillus rhamnosus (JB-1) revealed lower anxiety, decreased cortisol and other stress hormones, and even an increase in brain receptors for a neurotransmitters characteristic to curbing negative feelings such as fear and anxiety.
A study in 2011 from McMaster University tested the behaviors of normal 8 week old mice compared to 8 week old mice stripped of their gut microbiomes. Those not containing bacteria illustrated higher cortisol (stress) and depression rates, altering the level of BDNF in the brain, which plays a large role in mood regulation. Researchers from McMaster University also transplanted microbiomes from groups of timid mice with groups of outgoing mice. The outgoing mice became more timid when stripped of their normal bacteria, and vice versa.
The nerves that line the digestive tract from the esophagus to the anus, called the enteric nervous system, do not even require the brain at all, because when the vagus nerve is broken the enteric nervous system can still continue digestion due to the complexity of its neurons. The gut and the brain are connected for a time back when humans needed to know what kind of food to eat in order to detect what is most beneficial for survival, as it tells the brain to release dopamine when we eat palatable foods high in fats/sugars. The microbes in your gut however, produce 50% of your dopamine and 90% of your serotonin.
Works Cited:
Arnold, C. (2013, August 21). Gut feelings: the future of psychiatry may be inside your stomach. Retrieved February 05, 2017, from http://www.theverge.com/2013/8/21/4595712/gut-feelings-the-future-of-psychiatry-may-be-inside-your-stomach
A. (7, December 16). Gut feelings: How the microbiome may affect mental illness and interact with treatment. Retrieved February 05, 2017, from https://www.sciencedaily.com/releases/2016/12/161207093019.htm
Khazan, O. (n.d.). When yogurt affects the brain. Retrieved February 08, 2017, from https://www.theatlantic.com/health/archive/2014/09/when-yogurt-affects-the-brain/380542/
Reduced anxiety‐like behavior and central neurochemical change in germ‐free mice. (n.d.). Retrieved February 05, 2017, from http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2982.2010.01620.x/full
Reid, G. (n.d.). Faculty of 1000 evaluation for Is eating behavior manipulated by the gastrointestinal microbiota? Evolutionary pressures and potential mechanisms. F1000 - Post-publication peer review of the biomedical literature. doi:10.3410/f.718526950.793501602
Arnold, C. (2013, August 21). Gut feelings: the future of psychiatry may be inside your stomach. Retrieved February 05, 2017, from http://www.theverge.com/2013/8/21/4595712/gut-feelings-the-future-of-psychiatry-may-be-inside-your-stomach
A. (7, December 16). Gut feelings: How the microbiome may affect mental illness and interact with treatment. Retrieved February 05, 2017, from https://www.sciencedaily.com/releases/2016/12/161207093019.htm
Khazan, O. (n.d.). When yogurt affects the brain. Retrieved February 08, 2017, from https://www.theatlantic.com/health/archive/2014/09/when-yogurt-affects-the-brain/380542/
Reduced anxiety‐like behavior and central neurochemical change in germ‐free mice. (n.d.). Retrieved February 05, 2017, from http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2982.2010.01620.x/full
Reid, G. (n.d.). Faculty of 1000 evaluation for Is eating behavior manipulated by the gastrointestinal microbiota? Evolutionary pressures and potential mechanisms. F1000 - Post-publication peer review of the biomedical literature. doi:10.3410/f.718526950.793501602