We all know that drinking yogurt has benefits and we like the sweet and sour taste of yogurt, but not many people may know what the benefits of drinking yogurt actually are. Moreover, there are different varieties of yogurt such as lactobacillus milk and bifidobacterium milk, so how exactly to choose is also bewildering. In fact, these are all probiotics. The human intestine has up to nearly two kilograms of bacteria, tens of billions of them, and nearly a thousand species. In order to better understand and distinguish such bacteria in the human body, microecologists classify them into probiotics, commensal bacteria and passerine bacteria. The so-called probiotic bacteria is the existence of the lowermost layer of the human intestinal mucosa of a class of bacteria beneficial to the human body, mainly Lactobacillus, Bifidobacterium, anaerobic bacteria, etc., it is the hardcore defender of the intestinal mucosa. Symbiotic bacteria is a class of bacteria in the intestinal tract and human peacefully coexist, it is in the middle layer of the mucosa, some beneficial to humans, some when the local environment changes, it also shake, seize territory, cause local war, causing inflammatory reactions in the intestinal tract, mostly a class of enterococci, the other is the passing bacteria, is only a short stay in the intestinal tract, is the largest change in a class of bacteria, such as parthenogenic anaerobic bacteria, E. coli, etc. This kind of bacteria is in the most superficial layer of intestinal mucosa, if this kind of bacteria is superior, it will secrete toxins, etc., which will destroy the intestinal mucosa, cause leaky gut, inflammatory bowel disease, etc. Sometimes, it also runs through the broken mucosa to the blood and other organs, causing other diseases of different organs of human body, such as various skin diseases (eczema, dermatitis, urticaria, psoriasis, etc.). There are many reasons for the decrease of probiotics, such as the abuse of antibiotics, the addition of a large number of food additives, especially sweeteners, etc., which often tend to induce dysbiosis of the intestinal flora, resulting in the decrease of probiotics. Premature babies, caesarean section, premature milk feeding, etc. may change the structure of intestinal flora, and the proportion of probiotics will not be superior. Due to diet and other inattention, it is easy to change the microenvironment in the gastrointestinal tract, the acid-base balance in the gastrointestinal tract is not the same, it will also be unfavorable to the growth of some probiotics, such as small intestine pH alkaline, it is not conducive to the growth of lactobacilli, supplementation is also useless, the same reasoning is also suitable for the colon, etc. It is very necessary to eat reasonably and adjust the suitable pH value of the gastrointestinal tract, which is favorable to the growth of probiotics. Because probiotics have biophysical barrier effect on intestinal mucosa, it has the effect of inhibiting the reproduction of harmful bacteria, it can secrete immunoglobulin A, reduce the inflammatory response of the intestine, it can also neutralize toxins, synthesize vitamin A, K, etc. It also has obvious anti-aging effect. So supplementation of probiotics is beneficial to human health, the existing probiotics are triple, quadruple, mainly lactobacillus, bifidobacterium, bacillus terreus, etc. There is also a class of brucella bacteria should also be supplemented. For infant eczema, the younger the age and the earlier the onset of the disease, the more obvious the effect after supplementation, while for adult skin diseases, the longer the time, the less obvious the effect, but long-term supplementation is necessary, and supplementation of probiotics is good for correcting constipation or diarrhea, etc. Since intestinal probiotics need specific conditions and nutrients, supplementation should be given along with probiotics, etc., such as spirulina, seaweed, roughage, natural plants, etc. Under the guidance of doctors, adjusting a reasonable dietary institution and supplementing appropriate probiotics, together with other medications, some skin diseases, especially allergic skin diseases or psoriasis, can be cured or cease to occur for a long time.