Different probiotic products contain different amounts of bacteria, and different strains have different effects on the human body. Therefore, there is no such thing as a certain probiotic working better. Probiotics have the effect of regulating immunity, preventing and reducing pediatric diarrhea, improving constipation, and improving allergies. Probiotics should be selected according to specific conditions, such as antibiotics caused by intestinal mucosal injury generally choose Bacillus subtilis; bacteria or fungi caused by acute and chronic enteritis can choose Bacillus licheniformis; intestinal dysbiosis caused by intestinal dysfunction is often chosen bifidobacteria. Probiotic preparations can be used in combination, and the joint application of different probiotic species can play a synergistic role and achieve better therapeutic effects. However, not all strains of bacteria in any combination will be effective, so probiotic preparations should be taken in accordance with the doctor’s instructions to avoid self-medication.