The wisdom of Donguibogam resonates deeply within modern medicine as well. Modern medicine views the small intestine beyond a simple digestive organ, recognizing it as a 'second brain' involved in nutrient absorption, immunomodulation, and even our emotions. In particular, the vitamin D deficiency, chronic fatigue, decreased immunity, and feelings of depression we struggle with are very closely linked to the function of the small intestine.
First, let us examine vitamin D malabsorption. Vitamin D is a fat-soluble vitamin, and for it to be absorbed into our body, fat absorption in the small intestine must proceed smoothly. The villus and microvillus structures of the small intestine are key components that absorb nutrients, including fats. If their function declines or becomes damaged, vitamin D may simply be excreted without being properly absorbed, no matter how much sunlight you receive or vitamin D you consume. A shortage of digestive enzymes secreted by the pancreas or bile acids produced in the liver can also hinder fat absorption, leading to vitamin D deficiency. Intestinal conditions such as Crohn's disease, celiac disease, irritable bowel syndrome, and small intestinal bacterial overgrowth directly impair the small intestine's absorptive capacity, exacerbating these problems.
The connection to osteoporosis is also clear. Vitamin D acts as an essential hormone for calcium absorption. When vitamin D malabsorption occurs in the small intestine, calcium absorption is impaired, which weakens bone density over the long term and raises the risk of osteoporosis. From adolescent growth and development to bone health in old age, the health of the small intestine forms the foundation of our skeletal health.
Decreased immunity is likewise inseparable from small intestinal health. Did you know that approximately 70 to 80 percent of our body's immune cells reside in the gut? The intestinal wall houses a massive immune organ known as gut-associated lymphoid tissue, which plays a critical role in defending our body against pathogenic bacteria and harmful substances. When small intestinal function weakens, the intestinal mucosal barrier function breaks down, often referred to as leaky gut syndrome, allowing inflammatory substances or microorganisms to penetrate the bloodstream, triggering a systemic inflammatory response and disrupting the immune system. This can become a cause of chronic infections, allergies, and autoimmune diseases.
Chronic fatigue and depression are also intimately linked to the role of the small intestine. Various nutrients absorbed in the small intestine, such as B vitamins, iron, and magnesium, are essential for energy production and neurotransmitter synthesis. When the absorption of these nutrients is impaired, the body tires easily and succumbs to lethargy. Furthermore, research shows that approximately 90 percent of serotonin, known as the happiness hormone, is produced in the gut. Because the gut microbiota environment and small intestinal function influence serotonin production, an unhealthy small intestine can lead to emotional difficulties such as depression and anxiety.
Stress is a factor that further degrades small intestinal function. Chronic stress impairs intestinal motility, hinders blood circulation, and increases intestinal mucosal permeability, which can induce inflammation. In other words, what Donguibogam describes as the 'fire energy of the small intestine' is concretely explained in modern medicine through digestive enzyme activity, intestinal mucosal integrity, gut microbiota balance, and nervous system regulation. Can you now appreciate the true importance of the small intestine?
