Definition of Prebiotic
A prebiotic is a selectively fermented ingredient that results in specific changes in the composition and/or activity of the gastrointestinal microbiota, thus conferring benefit(s) upon host health. However, the field of prebiotics is advancing quickly, as evidenced by the fact that the prebiotic definition has been revised six times since it was first proposed 20 years ago. In March of 2015, a research group proposed that a prebiotic effect is the beneficial physiological outcome that arises from the modulation of the composition and/or activity of the gut microbiota through the metabolism of a nondigestible compound. The rapid pace of research in the area of the human microbiome and metabolomics is contributing to the evolution of the prebiotic and probiotics fields.