The aim of the present study was to examine
xylitol metabolism by
dental plaque collected immediately after the use of
xylitol gum. Plaque was collected from 12 individuals immediately before and after
xylitol exposure. The effect on
xylitol metabolism by
dental plaque of a 3 d discontinuation of the
xylitol exposure was also examined.
Xylitol metabolism by the plaque
suspensions was initiated by adding [14C]
xylitol and analyzed by HPLC. The results showed increased
xylitol metabolism after 11 wk of chewing
xylitol-containing gum. The ability to metabolize
xylitol was rapidly reduced after the discontinuation of the
xylitol exposure. It is suggested that an induction of
enzymes in one or more of the species of plaque bacteria may have caused this effect.
Glucose metabolism, which also was studied in the plaque samples, was decreased after
xylitol exposure, but increased again 3 d after cessation of the
xylitol exposure. It is suggested that the reduced glycolysis was caused by accumulation of intracellular xylitol-5-phosphate in some plaque bacteria during the
xylitol exposure.