Xylitol is a pentitol (five-carbon sugar alcohol) having meso-configuration, being derived from xylose by reduction of the carbonyl group. IXylitol is a naturally occurring five-carbon sugar alcohol found in most plant material, including many fruits and vegetables. Xylitol-rich plant materials include birch and beechwood. It is widely used as a sugar substitute and in "sugar-free" food products. The effects of xylitol on dental caries have been widely studied, and xylitol is added to some chewing gums and other oral care products to prevent tooth decay and dry mouth. Xylitol is a non-fermentable sugar alcohol by most plaque bacteria, indicating that it cannot be fermented into cariogenic acid end-products. It works by inhibiting the growth of the microorganisms present in plaque and saliva after it accummulates intracellularly into the microorganism. The recommended dose of xylitol for dental caries prevention is 6–10 g/day, and most adults can tolerate 40 g/day without adverse events. t has a role as a sweetening agent, an allergen, a hapten, a human metabolite, an algal metabolite, a Saccharomyces cerevisiae metabolite and a mouse metabolite.