In the process of biological evolution, microorganisms and their hosts (humans, animals, plants and microorganisms), microorganisms and microorganisms and between them and the environment, as a result of long-term mutual adaptation, under normal circumstances, the surface and body of the biological hosts are distributed a certain number of species and specific microbial groups that form an ecosystem and maintain ecological balance, called normal flora (Normal Flora). Normal Flora The normal flora is distributed on the surface of the body and in the external cavities, including the skin, respiratory tract, external auditory tract, digestive tract (oral cavity; stomach; jejunum; ileum; colon), nasal cavity, genitourinary tract, etc., among which the intestinal tract is the most abundant. These microorganisms have formed a symbiotic relationship with humans during the long evolutionary process. Many microorganisms are not only harmless but also beneficial to people. Among the normal flora, the intestinal flora is the most representative and the most fruitful to study. The total number of intestinal flora can be up to 1014 bacteria, 10-20 times the total number of human cells, including at least 14 genera (Bacteroidetes, Bifidobacterium, Lactobacillus digestive cocci, Streptococcus digestiveus, Enterococcus, Enterobacter, etc.), about 400-500 species of bacteria, 90%-99.9% are anaerobic bacteria (Bifidobacterium, Lactobacillus, etc.), Enterobacter, Enterococcus and other aerobic bacteria in very small numbers. Normal flora have many important physiological functions: 1, such as biological antagonism between flora, normal flora in the human body a specific bit of adhesion, colonization and reproduction, the formation of a bacterial film barrier. Through the antagonistic effect, inhibit and reject the invasion and swarming of passing flora, adjust the balance between the human body and microorganisms. 2, immune effect, normal flora can stimulate the host to produce immunity and clearance function. 3, detoxification effect, such as bifidobacteria can make the intestinal excess of gram-negative bacilli down to normal levels, reduce the absorption of endotoxins. 4, anti-tumor effect, can degrade, remove carcinogenic factors in the body, activate the body’s anti-tumor cytokines, etc. 5, anti-aging effect, etc. In addition to the above functions, the intestinal flora has nutritional effects on the human body. The normal microorganisms in the human intestine, such as Bifidobacterium, Lactobacillus, etc., can synthesize a variety of vitamins necessary for human growth and development, such as B vitamins (vitamin B1, B2, B6, B12), vitamin K, niacin, pantothenic acid, etc., and can also use protein residues to synthesize non-essential amino acids, such as aspartic acid, alanine valine and threonine, etc., and participate in the metabolism of sugars and proteins, and also promote the absorption of minerals such as iron, magnesium and zinc. Microecology is the study of the structure and function of normal microorganisms in the human body and their interrelationship with their hosts, and is an important part of life science. Microecology was first proposed by Volker Rush in Germany in 1977, and after 30 years of development, microecology research has made long-term development, among which the wide application of microecological agents in clinical practice is one of the important achievements of microecology development. Microecological agents, also known as probiotics, are preparations prepared by using normal microbial members or substances that promote the growth of microorganisms, which can achieve the purpose of disease prevention and health promotion by adjusting or maintaining the microecological balance. According to the material composition of microecological preparations can be divided into three categories: probiotics (Probiotics), prebiotics (Prebiotics), synbiotics (Synbiotics). Probiotics are live bacterial preparations and their metabolites that improve the micro-ecological balance of the host and play a beneficial role in improving the health level and health status of the host. Prebiotics are a non-digestible food component that selectively promotes the activity or growth and reproduction of beneficial intestinal flora, which plays a role in promoting host health and growth. The first prebiotic discovered was bifidobacterial factor. Later, a variety of indigestible oligosaccharides were found to be prebiotics. The most common oligosaccharides are lactose, sucrose oligosaccharide, cottonseed oligosaccharide and oligomaltose. These oligosaccharides are not decomposed and used by harmful bacteria, but can only be used by beneficial bacteria to promote the growth of beneficial bacteria and achieve the purpose of adjusting the flora. In recent years, our research found that some herbal preparations can also be used as prebiotics. Prebiotics have many advantages, there is no technical difficulty in maintaining the number of live bacteria, strong stability, long validity, not only can promote the growth of beneficial flora, but also can improve the immune function of the body. Hapten is a biological preparation combining probiotics and prebiotics, which is characterized by the effect of probiotics and prebiotics at the same time. The application of this kind of preparation has the trend of increasing day by day.