This review scrutinizes the physiological effects of prebiotic consumption, and how these materials relate to the concept
of dietary fiber and finally focused on the role
prebiotics and explains their impact on gut health . Because of their unique chemical structure, prebiotics, may be classified as functional food ingredients, and also because of Bifidogenic properties these materials reach the colon, where they may be completely unfermented. Therefore, they are absorbed and
metabolized in the glycolytic pathway, or directly stored as glycogen. This substance is quantitatively fermented by the indigenous intestinal microbiota; for that reason, it is considered to be a functional food. After reviewing their chemistry, origin, and physiological effects, it is the opinion of the authors that prebiotics have the basic common characteristics dietary fiber. That is resistance to digestion, absorption in the small intestine, fermentation in the colon to produce short-chain fatty acids that are absorbed and metabolized in various parts of the body. In addition, consumption of prebiotics / dietary fiber help to shorten fecal transit time, increase fecal bulk and reduce constipation.Corresponding author: Phone: 91 80 23636421/ 429 & Fax: 91 80 2363666E mail . reyed@bio.la rmrkater@mail.health-ua.com