**2. Probiotic products**

Many publications said using probiotic products can be a factor in improving the health of the digestive system, reproductive organs, and oral hygiene.

Probiotic bacteria should have the ability to adhere to and colonize surfaces in the oral cavity, have a good shelf life, and be nontoxic. Two main groups probiotic bacteria are *Lactobacillus* and *Bifidobacterium*. The *Lactobacillus*, as a member of oral microbial flora, can play an important role in the microcosm balance of the oral cavity. *B. bifidum*, *B. longum*, and *B. infantis* are the probiotic species of *Bifidobacterium*.

Today, with the increasing awareness of people about the beneficial effects of probiotic bacteria, consumption of functional foods is increasing. Functional foods are such food that promotes health [2, 3].

Functional foods must have three items:

1.they have a different effect from a nutrition standpoint;


New food products are converted into probiotic foods by adding probiotic bacteria. These foods include a variety of different types such as cheese, ice cream, milk-based dessert, baby milk, and mayonnaise. The main thing is the texture of these foods [5].

The fourth mechanism of how probiotic bacteria work in the mouth include:

1. competition between probiotic bacteria and pathogenic bacteria in adhesion to mucus and teeth, which in this way prevents the pathogenic bacteria from attaching;

