Probiotics are microorganisms that provide health benefits when consumed, as claimed by some.[1] The term probiotic is currently used to name ingested microorganisms associated with beneficial effects to humans and animals.[2] Introduction of the concept is generally attributed to Nobel Prize recipient Eli Metchnikoff,
who in 1907 suggested that "the dependence of the intestinal microbes on the food makes it possible to adopt measures to modify the flora in
our bodies and to replace the harmful microbes by useful microbes".[3]
A significant expansion of the potential market for probiotics has led to higher requirements for scientific substantiation of putative
beneficial effects conferred by the microorganisms.
Source: Wikipedia : http://en.wikipedia.org/wiki/Probiotic