There are several reasons why probiotics are ineffective, including not choosing the right type of probiotics, not replenishing the right amount of probiotics, taking probiotics in the wrong way, and personal health reasons. 1. Probiotics did not choose the right type: there are many types of probiotics, and each has a different function, targeted supplementation, more able to play the corresponding effect. For example: Bifidobacterium can reach the large intestine, promote intestinal peristalsis, help defecation, regulate intestinal disorders; Lactobacillus acidophilus and Lactobacillus rhamnosus can improve allergies. 2. Insufficient number of supplementation: To achieve the effect of probiotic supplementation, it is necessary to supplement at least 50~10 billion each time, and the more active bacteria the better. This is because probiotics are anaerobic, do not tolerate high temperatures, and are difficult to reach the intestinal tract during consumption. Therefore, each time the intake of a sufficient amount of probiotics, in order to retain as much as possible part of the intestinal survival. 3. Incorrect method of taking probiotics: when taking probiotics, it is best to use 37℃ warm water to avoid killing probiotics, and secondly, after taking probiotics, it should be taken within 30 minutes to avoid probiotics losing their activity, and probiotics are more sensitive to acidity and alkalinity, so you should not take too acidic or alkaline food at the same time when you are taking probiotics. 4. Individual physical differences: Probiotics are foreign flora, so after their arrival in the human intestinal tract, they may not be adapted to the individual’s intestinal environment, resulting in their inability to survive and play a role in the effect. With digestive symptoms, it is recommended to go to the hospital and take probiotics under the guidance of a doctor.