When it comes to bacteria, most people think of them as harmful and causing diseases and infections. However, not all bacteria are "bad". We coexist with microorganisms that are invisible to the naked eye. When our immune system is functioning properly, these microorganisms are harmless to us, and some even benefit our bodies. We refer to these "well-behaved" microorganisms as the normal flora.
Distribution of Flora
Various types of microorganisms exist in our oral cavity, nasal cavity, and gastrointestinal tract, with the largest and most diverse population found in the intestines. Approximately 80% of the normal microorganisms in the human body are concentrated in the intestines, with a population of over 100 trillion (about ten times the total number of human cells). They consist mainly of bacteria, with four to five hundred species, and the majority are anaerobic bacteria that do not require oxygen. The total weight of these microorganisms exceeds one kilogram.
Formation of Flora
When we are born, our bodies do not have any microorganisms. However, within a few hours, microorganisms enter our bodies through various channels such as breathing and breastfeeding, and occupy suitable positions to start reproduction. Not all microorganisms can successfully colonize in the human body. After an 8-hour selection process, microorganisms that can peacefully coexist with the human body are retained and become part of the normal flora.
Roles of Intestinal Flora
These bacteria living in the intestines are not redundant or harmful. They understand the concept of mutual benefit in the human body. While enjoying the living space provided by the human body, they also show gratitude.
Inhibition of Pathogenic Microorganisms
They can inhibit the growth of pathogenic microorganisms. For pathogenic microorganisms to cause trouble in the human body, they must first find a foothold. However, with the presence of the normal flora, pathogenic microorganisms have to compete with the existing microbial community in the body, and in most cases, these pathogenic microorganisms are defeated. The normal intestinal flora in the human body has no competition, making it easy to fend off foreign invaders. Therefore, as long as the intestinal flora remains "well-behaved," the human body should coexist with them peacefully. However, the misuse of antibiotics can disrupt the balance and provide an opportunity for foreign bacteria to cause trouble.
Synthesis of Essential Nutrients
The normal microorganisms in the human body can also synthesize some essential nutrients such as vitamin K, vitamin B, and niacin, which are then absorbed by the body. In addition, intestinal microorganisms also play a role in regulating the immune system and degrading carcinogenic substances such as nitrosamines in food.
Imbalance of Flora Can Lead to Diseases
Just like a macroscopic ecosystem, the balance of the intestinal microecosystem is crucial for human health. If the balance of the intestinal microecosystem is disrupted, it can lead to diseases. For example, the excessive use of antibiotics often causes an imbalance in the intestinal flora, resulting in diarrhea. In severe cases, it can develop into refractory pseudomembranous colitis. Antibiotics are a double-edged sword. While they can kill pathogenic bacteria, they can also kill many normal intestinal microorganisms, leading to an imbalance in the intestinal microecosystem.
Many studies have also shown that the imbalance of intestinal microorganisms is associated with autoimmune diseases, irritable bowel syndrome, obesity, diabetes, and even obesity is directly related to changes in the intestinal flora.
Maintaining Intestinal Flora Health
The use of antibiotics can have a serious impact on the intestinal flora, easily causing an imbalance. Therefore, antibiotics should be used according to medical advice and not abused or overused.
A high-fat, high-sugar diet can cause a decrease in symbiotic bacteria, leading to an imbalance in the intestinal flora. Therefore, it is important to maintain a balanced diet. Dietary fiber can serve as food for many of our intestinal bacteria. Insufficient intake of dietary fiber can leave some bacteria starving, and they will start consuming the mucopolysaccharides on the surface of the colon.
In summary, supplementing with probiotics and maintaining a balanced diet may be helpful, but these studies are still in the early stages. Further research is needed to explore how to maintain health by regulating the intestinal flora.
