ABSTRACT
Experts have debated on how to de…ne probiotics. One widely used de…nition, developed by the World Health Organization and the Food and Agriculture Organization of the United Nations, is that probiotics are “live microorganisms, which, when administered in adequate amounts, confer a health bene…t on the host.” Microorganisms are tiny living organisms-such as bacteria, viruses, and yeasts-that can be seen only under a microscope.
