**3. Probiotics background**

As we know, the presence of microorganisms in the body always had been a concern of a large group of scientists. Because the health of the oral and intestinal organs is depends on the balance of these microorganisms and their functioning [10]. For many years, scientists and doctors have been using antibiotics to improve the function of the oral cavity, lymph system, and intestinal organs and control the demographic of these microorganisms. However, the widespread use of antibiotics not only caused a lot of problems in the human body but also led to microorganisms exhibiting resistance and even in some cases caused new species in microorganisms. All these problems forced scientists and researchers to find new methods for controlling microorganisms in the body organs.
