I believe everyone has heard the saying "Disease comes from the mouth" since childhood. There is also a Western proverb "You are what you eat". Although the two words have different meanings, they have the same meaning. The message expressed is that food directly affects our health. Hippocrates, the father of Western medicine, famously said: "Let food be your medicine; medicine is your food." China's "diet therapy" for thousands of years has been popular to this day, showing that the East and the West have the same view on the importance of food. , but in addition to food, the more critical impact is the functional state of the gastrointestinal tract.

For a long time, most people have the illusion that anything that can be eaten is food, and what has been eaten into the stomach belongs to our body. In fact, the intestines are completely connected to the outside world from the "mouth" to the "anus". Any food eaten does not belong to the body before it is absorbed. What's more important is that in addition to foods with nutritional value, daily eating also includes numerous processed foods, junk and fake foods, and there are also a large number of "harmful substances" included in the process, including environmental toxins and chemical additives. , preservatives, artificial colors, allergens, residual drugs, oxides, carcinogens, bacteria, foreign matter, etc. These harmful substances not only fail to provide nutrition, but can even damage the intestinal mucosa, hinder normal food digestion and absorption, and increase liver function. Detoxification burden, and can cause many so-called "adverse food reactions" (such as food allergies, gastroenteritis, etc.). Obviously, our intestines are really a mixture of cows and soap, dragons and snakes. Therefore, the intestine must be able to distinguish between normal food and harmful substances in order to maintain its integrity. This is also an important function of the intestine that cannot be ignored.

On the other hand, every time we eat "food", it must be decomposed (digested) and absorbed by various enzymes (enzymes), gastric acid, bile salts, pancreatic juice, etc. (the food enters the blood after decomposition) ), assimilation (nutrients enter the cells) before they can be truly utilized by the human body, such as steak turning into amino acids, pasta turning into glucose, cooking oil turning into fatty acids, etc. Before these processes are completed, all these so-called foods are just external molecules. The body is a complete "stranger" and needs to be "probated", so the intestines must be strictly controlled. In other words, in addition to digestion and absorption, the intestine is actually a very important barrier for the human body. It is also the body's largest lymphatic immune system and has the most lymphoid tissue in the body (so it has enough power to deal with harmful substances). Basically, the digestive tract has three defense capabilities:

1. Physical: epithelial cells are tightly connected to prevent harmful substances from slipping into the blood, and "intestinal mucus" can prevent bacteria and foreign matter molecules from adhering to the intestinal wall. lesions occur.

2. Chemical: Various secretions such as enzymes, gastric acid, bile salts, etc. help decompose food and eliminate harmful bacteria.

3. Immunity: The intestinal immune system is the largest immune system in the body and is responsible for producing "secretory immunoglobulin A (slgA)" as the best "coast defense" of the human mucosa, blocking the likes of Invasion of viruses, bacteria, mold, foreign matter, toxins, etc. In fact, 70% of the body's immune system surrounds the intestines, especially concentrated near the small intestine. The intestines produce more immunoglobulins every day than any other part of the body, but long-term poor diet or prolonged stress will reduce it. As a result, mucosal problems such as respiratory tract infections, stomatitis, cystitis, vaginitis, gastroenteritis, etc. become prone to occur.