The various kind of food substances containing probiotic good bacteria like Lactic Acid Bacteria (LAB) and Bifidobacteria have been used up for centuries. People use them frequently as a natural resource to promote good health even without knowing of their active ingredients or how they work. Since, the benefits of some of these good bacteria are now well documented; the present paper is an attempt to summarize the existing knowledge on the scope of probiotics in the light of recent researches carried out so far.