Just as the Donguibogam speaks of the close relationship between the liver and the spleen and stomach, modern medicine explains these remarkable interactions in our body through the concept of the gut-brain axis. Beyond being merely an organ for digestion and an organ for thinking, our brain and gut constantly converse like friends and influence one another.
The key pathway for this conversation is the vagus nerve. The vagus nerve acts like a highway directly connecting the brain and the gut; stress signals sent from the brain are quickly transmitted to the gut, and information regarding the gut's state is reported in real time to the brain. When we undergo stress, the brain secretes stress hormones such as cortisol. When these hormones travel down the vagus nerve and reach the gut, they can contract or relax the smooth muscle that regulates intestinal motility, which can disrupt digestive function.
Furthermore, stress increases intestinal mucosal permeability, which can induce leaky gut syndrome. When the intestinal wall loosens, harmful substances that should not pass through can penetrate into the bloodstream and cause inflammation. This in turn stimulates the enteric nervous system, potentially leading to a vicious cycle that worsens irritable bowel syndrome symptoms. In particular, more than 90% of serotonin, called the happiness hormone, is produced in the gut; stress also affects the production and secretion of this serotonin, which can simultaneously trigger mood changes and gut symptoms.
Moreover, the gut microbiome, where countless microorganisms reside, lives within the gut. These microorganisms are deeply involved not only in our digestion, but also in our immunity and even our emotions. Stress disrupts the balance of beneficial gut bacteria and causes harmful bacteria to proliferate, harming gut health, which can soon be conveyed to the brain and amplify feelings of anxiety or depression.
In the end, the impact of stress on the gut is intertwined with complex physiological reactions that cannot be fully explained merely by the word neurotic. The wisdom of the Donguibogam—that when the liver's function of free coursing collapses, the spleen and stomach waver—aligns remarkably with modern medical discoveries showing that the brain and gut communicate comprehensively across the nervous system, endocrine system, immune system, and microorganisms to maintain balance in our body. You can see how important it is not to simply turn away from the signals your gut sends, but to understand and soothe them deeply, right?
