Prebiotics are non-digestible food ingredients which beneficially
affect the host by selectively stimulating the growth of and/or
activating the metabolism of one or a limited number of health
promoting bacteria in the intestinal tract, thus improving the host’s
intestinal balance. All prebiotics to date have been carbohydrates,
ranging in size from small sugar alcohols and disaccharides, to
oligosaccharides and large polysaccharides. The defining criteria of
prebiotics are
(1) A prebiotic should neither be hydrolyzed nor absorbed in the
upper part of the gastrointestinal tract.
(2) It should be a selective substrate for one or more potentially
beneficial commercial bacteria in the large intestine.
(3) Alter the colonic microenvironment toward a healthier
composition