Effect of xylitol on the growth and glycolysis of acidogenic oral bacteria.

We investigated the effect of xylitol on the growth of different oral bacteria in the presence of glucose. Xylitol inhibited the growth of all but one of ten strains of S. mutans and failed to inhibit the growth of the lactobacilli, actinomycetes, and other streptococci tested except S. sanguis 10556, which was slightly inhibited. However, the rate of acid production of the sensitive S. mutans strains was not equally affected by xylitol. These data, obtained with pure cultures of acidogenic oral bacteria, may explain the lack of an in vitro inhibitory effect of xylitol on dental plaque samples.