The first effect of sour milk, can maintain the balance of intestinal flora, is conducive to maintaining the micro-ecology of the intestinal tract, because sour milk in the preparation process, more or less will contain some probiotics, these bacteria to maintain the balance of intestinal flora has a very important role. The second effect of sour milk, can provide the body with rich calcium, and yogurt in the calcium and phosphorus ratio of the appropriate absorption rate will be higher, in the prevention of osteoporosis, the prevention and treatment of waist and knee weakness will be very obvious. The third effect of sour milk, can provide the body with high-quality protein, in the prevention of muscle wasting disease and improve the body’s immunity to the role of sour milk will be very obvious.