The first thing you need to know is which probiotics are added to this toothpaste. If it's just a common strain, it's useless if it's not attached to the mouth! Lactobacillus paracasei is a kind of bacteria useful for oral cavity, which can inhibit oral pathogenic bacteria (see figure). It shows that if there is this strain in toothpaste, it has certain effect! There is also the use time. Toothpaste is not a medicine (of course, the medicine will not take effect immediately), and the strain has a long attachment time, usually in 1-2 months. So if the toothpaste you choose really contains probiotic toothpaste that is helpful to your mouth, please use it for enough time. Don't say it will be useless in two or three days. Taking medicine is not so fast! I hope my answer is helpful to you.