Prebiotics were defined in 1995 as non-digestible food ingredients beneficially affecting the host by stimulating the growth and/or activity of one or more bacteria in the colon, thus improving health. The proliferation of certain bacteria by fermentation of non-digestible carbohydrates has been shown to be able to inhibit the colonization of the intestine by pathogens, thus giving a protective effect vis-à-vis acute or chronic intestinal disorders. The fermentation of prebiotics may promote some specific physiological functions through the release of metabolites from the bacteria, especially short chain fatty acids (acetate, propionate, butyrate, lactate, etc.) into the lumen of the intestine. Short chain fatty acids may act directly or indirectly (by modifying the pH) on intestinal cells and may be involved in the control of various processes such as the proliferation of mucosa, inflammation, colorectal carcinogenesis, mineral absorption and the elimination of nitrogenated compounds. Curiously, numerous papers have hinted at the possibility that prebiotics may have systemic physiological effects that are related to beneficial effects on lipid metabolism and various cardiovascular risk factors.