Probiotics are normally bacteria and other microorganisms that have beneficial effects on the human and animal health. Probiotic is a live microbial food supplement that beneficially affects the host animal or human by improving the intestinal microbial balance. In the context of the humans it also includes fermented food products, e.g. yogurt, curd, and lyophilized bacteria etc. Originally the term was used to denote microorganisms promoting the growth of other microorganisms but has now been extended to refer to viable microorganisms that promote or support a beneficial balance of the autochthonous microbial population of the gastrointestinal tract. Such organisms need not necessarily be constant inhabitants of the gastrointestinal tract, but they should have beneficial effect on the general and health status of man and animal