How can modern medicine explain our ancestors' wisdom regarding cold diarrhea? This chronic abdominal coldness and diarrhea are deeply related to a malfunction of the gut-brain axis. The digestive organs of our body are not merely factories that process food; they possess neural networks so delicate that they are called a second brain intricately connected to the autonomic nervous system, or the gut brain.
When the abdomen becomes cold, problems can arise in the regulatory function of this gut-brain axis. As the temperature of the abdomen drops, the activity of the autonomic nervous system that regulates intestinal motility, particularly the parasympathetic nerve, tends to decline or lose balance. The parasympathetic nerve is primarily responsible for rest and digestion, and when this function declines, intestinal peristalsis becomes irregular and digestive enzyme secretion also fails to occur smoothly. Like a slowed conveyor belt, food is not properly broken down and moves down rapidly, inducing diarrhea.
In addition, abdominal coldness exerts a critical influence on the gut microbiota environment. Inside our intestines, countless beneficial bacteria and harmful bacteria live in balance, but when body temperature drops, it becomes an environment where it is difficult for beneficial bacteria to remain active. It is just like plants that need warmth to grow well freezing in the cold. When beneficial bacteria decrease and harmful bacteria become dominant, the protective function of the intestinal mucosa weakens, and inflammatory reactions occur more easily, which can lead to problems such as leaky gut syndrome. In this state, toxins or microorganisms within food leak into the bloodstream, triggering a systemic inflammatory response, and adversely affecting the autonomic nervous system to cause chronic fatigue, lethargy, and even depressive feelings.
Furthermore, under stress, our body activates the sympathetic nerve for the fight-or-flight response, and when this sympathetic nerve becomes excessively elevated, the blood flow volume going to the intestines decreases, making the gut even colder and more sensitive. In other words, psychological stress creates a vicious cycle that further worsens abdominal coldness and chronic diarrhea. Therefore, chronic abdominal coldness and diarrhea should not be regarded as simple indigestion, but accepted as a signal that the entire balance of our body is breaking down, requiring a proactive response. Rather than simply taking an antidiarrheal, focusing on stabilizing the fundamental gut-brain axis and improving the gut microbiota environment is far more important.
