**2. Probiotic bacteria**

The international definition of probiotics is "a living microorganisms that induce health benefits and advantages on the host, especially when it is used in an adequate amount." Over the years, different definitions of probiotics are established based on their mechanisms, site of action, delivery format, method, or host. As probiotics have various effects, they are used in different areas [1].

### **2.1 History**

The term probiotic comes from the Greek language meaning "for life." It was first introduced by Lilly and Stillwell in 1965 to describe substances that stimulate the growth of microorganisms. In 1971, Sperti used the probiotic term to define
