There is no optimal time to take probiotics; it needs to be determined on a case-by-case basis. Be careful to avoid taking with antibiotics to avoid the effect of probiotics to be ineffective. Probiotics are commonly used in the clinic for microecological regulation of drugs, which may include bifidobacteria, lactobacillus, bacillus subtilis and so on. Its main mechanism is that it can directly supplement the normal intestinal flora, or establish an environment conducive to the growth of normal intestinal flora, promote the growth of intestinal flora, realize the stability of intestinal flora, and improve the phenomenon of dysbiosis. Clinically, probiotics can be widely used in the symptoms of diarrhea and bloating caused by intestinal flora imbalance, as well as the adjuvant treatment of inflammatory bowel disease. It is recommended to visit the hospital before taking probiotics, and be guided by the doctor according to the actual condition.