A prebiotic is defined by the International Scientific Association for Probiotics and Prebiotics  as “a substrate that is selectively utilized by host microorganisms conferring a health benefit.” This statement keeps a microbiota-mediated health benefit, but does not restrict a prebiotic component to be a food or a carbohydrate nor are the effects limited to the gastro-intestinal tract (Gibson et al. 2017). This definition still requires that a prebiotic substance reaches (colonic) microorganisms intact and that the beneficial effect is mediated via actions of selected local microorganisms (La Fata et al. 2017).