Probiotics can synthesize digestive enzymes, promote the absorption of intestinal nutrients, remove or reduce the adhesion of pathogenic bacteria, maintain the structural balance of intestinal flora, and improve symptoms such as constipation, diarrhea and indigestion. Probiotics contain peptidoglycan, lipoteichoic acid and other components, which can stimulate the host's immune system, improve the body's immunity, enhance the activity of innate immune cells and natural killer cells, and protect the body's health.