There are more than 10 trillion huge microbial groups in human skin and intestines, and their number is more than 10 times of the total number of human cells, which is considered as another set of genomes besides human cells. Under normal circumstances, the vast majority of bacteria in the gastrointestinal tract are beneficial to the human body, but due to various factors, the intestinal flora will also be unbalanced, and once it is unbalanced, it is easy to induce various chronic diseases.
The second organ of the human body
We collectively refer to the bacteria living in the intestine as intestinal flora. Their total weight in the human body is 2~3 kg, and there are more than 1,000 species. More than 50% of the feces we excrete every day are composed of these bacteria and their corpses. These small bacteria are symbiotic with our human body. They are rooted in the intestine for a long time to maintain our health, so we also call the intestinal flora "the second organ of the human body".
First of all, intestinal flora can shield and influence the immune system by itself, and prevent pathogenic bacteria from invading the human body. Intestinal flora adheres to the mucosal layer on the surface of the inner wall of the intestine, forming a barrier composed of bacteria. Intestinal flora inhibits the growth of pathogenic bacteria through the dominant symbiotic bacteria activities, and prevents pathogenic bacteria from entering the human body through this barrier. At the same time of passive defense, intestinal flora can stimulate the body to form more lymphatic organs in the intestine, and increase the level of immunoglobulin in plasma and intestinal mucosa, so that the immune system is in a moderately active state, so as to maintain an effective immune effect on invading pathogens.
In addition, intestinal flora has regulating and nutritional effects on the intestine. It has been reported that the existence of intestinal flora, especially the nutritional function of short-chain fatty acids produced by it, can make the growth of intestinal epithelial cells more active. In addition, intestinal flora can also regulate the differentiation of intestinal mucosal epithelial cells. This means that with normal intestinal flora, intestinal mucosa can be repaired more quickly.
Recent studies have shown that intestinal flora has an important relationship with human metabolic diseases. In addition, there are many other relationships between intestinal flora and health. Carotenoids produced by intestinal flora can reduce the risk of atherosclerosis and stroke to some extent. Normal intestinal flora can regulate the body’s response to allergens through the influence on lymphocytes, thus affecting the occurrence of allergic diseases. Even more surprising, there is evidence that the structural changes of intestinal flora can even affect the behavior patterns of the body.
Bacteria are also divided into good and bad
"Bacteria exceeded the standard" and "food was found to have bacteria" … People often talk about "bacteria" discoloration, but they don’t know that bacteria are also good or bad. Microbial communities are constantly influenced by many factors in the process of growth, including heredity, age, gender, diet and lifestyle. Everyone’s intestinal microbes have their own characteristics, but in healthy individuals, the relative abundance and distribution of bacterial species are very similar, and they all play a role in maintaining people’s overall health. There are "beneficial bacteria" that provide positive energy, "harmful bacteria" that love to make trouble, and some originally harmless bacteria that may take advantage of the situation and cause harm to the body. Such bacteria are called "opportunistic pathogens" or "conditional pathogens".
The normal flora of gastrointestinal tract can be divided into aerobic bacteria, facultative anaerobic bacteria and anaerobic bacteria. The most dominant is anaerobic bacteria, accounting for 99% of the total flora. The types and quantities of bacteria in the stomach, duodenum and jejunum are less, and the bacteria in the ileum begin to increase. In the colon, the types and quantities of bacteria increase more significantly, most of which are anaerobic bacteria, and Bifidobacterium, Bacteroides and Lactobacillus are absolutely dominant, while Clostridium and Staphylococcus, which are potentially pathogenic, account for only a few.
The imbalance of flora leads to many diseases.
If the intestinal flora is out of balance, health will go wrong. When beneficial bacteria can’t compete with harmful bacteria or conditional pathogens, they show bacterial infection, and symptoms of gastrointestinal diseases such as diarrhea, abdominal pain, vomiting and fever appear. For example, the endotoxin produced by the imbalance of intestinal flora will increase the burden of liver detoxification and cause liver damage. These toxins will also enter our brain, causing abnormal brain development, causing autism, depression, Alzheimer’s disease and other symptoms. In addition, the imbalance of intestinal flora will also lead to cardiovascular and cerebrovascular diseases such as atherosclerosis.
There are five main reasons for the imbalance of intestinal flora: 1. Long-term unbalanced diet. For example, eating too much meat or vegetables and eating unhealthy food for a long time; 2. Ingestion of food contaminated by bacteria. Reduce resistance, make conditional pathogens "worse", or ingest too many harmful bacteria, imbalance of intestinal flora, and diarrhea symptoms; 3. Age increases. With the increase of age, some beneficial bacteria decrease and harmful bacteria increase, and the body’s immunity weakens; 4. Use certain drugs. Excessive use of antibiotics leads to imbalance of intestinal flora and decreased immunity; 5. Gastrointestinal dysfunction. Organic causes lead to imbalance of intestinal flora and decreased immunity.
Diet regulation is safe and effective.
Now we have a safe, effective and scientific conditioning method, that is, taking microecological preparations. This preparation mainly includes three types, namely probiotics, prebiotics and synbiotics. Probiotics contain a certain number of live bacteria preparations; Prebiotics can promote the growth of intestinal probiotics; Synbiotics is a mixture of probiotics and prebiotics, which can not only supplement the probiotics in our body, but also promote the growth of probiotics.
Yogurt is a good choice to supplement probiotics. It contains plenty of protein, and also contains Lactobacillus bulgaricus and Streptococcus thermophilus, but these two kinds of bacteria can’t colonize in our intestines, and yogurt at room temperature contains no live bacteria.
In addition to yogurt, there are many lactic acid bacteria drinks on the market at present. This kind of drink has a very high sugar content, and its nutritional value is relatively low compared with yogurt. Moreover, most of these drinks are stored at room temperature, so it does not contain live bacteria.
There is also an active lactic acid bacteria beverage, which requires strict cold chain transportation and cold storage. However, for people with gastrointestinal discomfort, drinking cold drinks often stimulates the intestines, and there is no way to guarantee the probiotic activity contained in such drinks.
In addition, bad eating habits will destroy the balance of intestinal flora, for example, a high-fat diet will change the intestinal flora. Adjusting the dietary structure and developing good eating habits play an important role in maintaining the dynamic balance of intestinal flora.
Intestinal flora changes with age, and some studies show that the number of bifidobacteria in the intestine of the elderly is significantly reduced. Therefore, in the diseases related to intestinal flora imbalance in the elderly, proper application of microecological agents is conducive to the recovery of the health of the elderly.
Commonly used microecological agents include live bacterial agents such as Bifidobacterium, Lactobacillus and Enterococcus. Increasing the number of beneficial bacteria can not only regulate the balance of intestinal flora, but also enhance the immunity of the body. ▲ (This lecture was written by Cui Yuyan, a special correspondent of this newspaper)
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