Children’s probiotics whose role can be summarized as: i. Prevention and improvement of diarrhea. Poor eating habits or taking antibiotics can break the balance of intestinal flora, which can lead to diarrhea. Probiotic supplementation helps balance the intestinal flora, i.e., restore the normal intestinal pH value and relieve the symptoms of diarrhea. Second, relieve the symptoms of lactose intolerance. Lactobacillus can help the body break down lactose and relieve the symptoms of diarrhea, flatulence and other discomforts, which can be consumed with milk. Third, to prevent reproductive system infections. Lactobacillus acidophilus in sour milk can inhibit the reproduction of Candida albicans in the vagina, which can prevent reproductive system infections and can help repair the microcirculation of the reproductive system. Fourth, enhance the immunity of the body. There is a very well-developed immune system in the intestine, and probiotics can regulate the immune activity that is too low or too high to a normal state by stimulating the immune function in the intestine.