What is xylitol?

Xylitol is a naturally derived polyol and sugar alternative. We source ours from beech trees (‘Xyl’ is Greek for wood – think ‘xylophone’) while other popular sources include birch trees and corn cobs. It tastes similar to sugar but has 40% fewer calories, a very low GI (of 7) and most importantly, it has active dental health benefits. It has been the subject of over 600 clinical studies and it is well established that habitual xylitol consumption decreases caries occurrence. Products containing xylitol are now endorsed by over 15 dental associations worldwide and xylitol gum has a European Food Standards Authority approved health claim for plaque reduction.

So how does it work?

Xylitol is unique among polyols because as well as the passive benefits of not being sugar, it has active benefits, reducing the amount of Mutans Streptococci (MS) bacteria and plaque and acting against low pH in the mouth.

MS bacteria is reduced

Xylitol inhibits the growth of MS through a ‘futile metabolic cycle’ whereby the bacteria metabolises the xylitol thus wasting energy and ultimately limiting its metabolic efficiency(1).


Plaque is reduced

Xylitol reduces the amount of plaque(2) through the reduction in the population of extracellular polysaccharides (EPS) which contribute to the adhesiveness of MS so they cannot colonise to form plaque. Plaque is therefore also easier to remove through everyday brushing or through the constant washing action of the saliva. Significant reductions in bacteria and total plaque quantities can be observed following periods of consumption from as little as two weeks. The plaque stays reduced during xylitol consumption and regrowth is slow when it has ceased(3).


Reduction in “acid attacks”

Not only is the amount of plaque reduced but plaque does not produce acids from xylitol so it acts against low pH in the mouth(4).


Xylitol consumption by mothers prevents caries occurrence in their children

Mothers are the primary source of MS bacteria in their children(5). In studies of young children (3 months to 24 months) consumption of xylitol by the mother has been shown to reduce the child’s MS colonisation by as much as 80%(6). The positive impact of this early avoidance of MS can lead to significantly lower caries occurrence even at 5 and 10 years old(7).

What’s the ideal dosage?

To get these benefits, patients should consume 5g of xylitol a day(8), ideally at intervals after meals.



  1. Milgrom et al 2006, Soderling et al 2008
  2. Soderling et al 1997, Maquire and Rugg-Gunn 2003, Cronin et al 1994
  3. Makinen et al 1985, Soderling et al 1987, Soderling 1997
  4. Havenaar 1978, Soderling et al 1989, Splieth et al 2009, Campus et al 2009
  5. Berkowitz and Jordan 1975, Davey and Rogers 1984, Caufield et al 1985, 1987, 1995
  6. Soderling et al 2000, Thorild et al 2003, 2006, Nakai et al 2010, Fontana et al 2009, Olak at al 2012
  7. Isokangas et al 2000, Laitala et al 2010
  8. Makinen 1996, Milgrom 2009