Xylitol is a five-carbon sugar alcohol that reduces the incidence of caries by inhibiting the growth of oral streptococci, including Streptococcus mutans. Since xylitol is transported via the fructose phosphotransferase system, we hypothesized that it could also affect the growth of other oral bacteria strains. We tested the effects of xylitol against non-periodontopathogenic oral bacteria frequently found in healthy subjects as well as periodontopathogens including Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia. With 5% xylitol, Streptococcus vestibularis and Gemella morbillorum showed marked growth inhibition. With 10% xylitol, all of the tested periodontopathogens and Actinomyces naeslundii showed marked growth inhibition, whereas the growth inhibition of Neisseria mucosa, Neisseria sicca and Veillonella parvula was mild only. Xylitol is a widely used sweetener and the concentration used in our experiment is easily achieved in the oral cavity. If xylitol reduces the growth of periodontopathogens more preferentially, it could also reduce the prevalence of these pathogens and have clinical utility in the prevention or treatment of periodontal disease.
Actinomyces ; Bacteria* ; Forsythia ; Fructose ; Gemella ; Incidence ; Mouth ; Neisseria mucosa ; Neisseria sicca ; Periodontal Diseases ; Porphyromonas gingivalis ; Prevalence ; Streptococcus ; Streptococcus mutans ; Sweetening Agents ; Treponema denticola ; Veillonella ; Xylitol*

OBJECTIVETo investigate the correlation between the changes in oral microflora and recurrent oral ulcers (ROU).

METHODSSalivary sample were collected from ROU patients with oral ulcers (group T) and those with ulcer healing (group C) as well as from ROU-free individuals (group N). The quantity of 3 common bacteria (Streptococcus sp., Veillonella sp., and Neisseria sp.) in the salivary samples was detected and compared between the 3 groups.

RESULTSThe quantities of Streptococcus sp. (7.30-/+0.89 copies/ml) and Veillonella sp. (8.29-/+0.77 copies/ml) in group T were significantly lower than those in group N (8.15-/+0.55 and 8.93-/+0.76 copies/ml, respectively, P<0.01), but similar with those in group C. The quantity of Streptococcus sp. (7.51-/+0.81 copies/ml) in group C was significantly lower than that in group N (8.15-/+0.55 copies/ml, P<0.01), but the quantity of Veillonella sp. was similar between the two groups. No significant difference were found in the quantity of Neisseria sp. between the 3 groups.

CONCLUSIONThe quantity of oral microflora differs significantly between patients with recurrent oral ulcers and normal individuals, suggesting a possible correlation between oral microfora and recurrent oral ulcers.

Adult ; Colony Count, Microbial ; Female ; Humans ; Male ; Mouth Mucosa ; microbiology ; Neisseria ; isolation & purification ; Saliva ; microbiology ; Stomatitis, Aphthous ; microbiology ; Streptococcus ; isolation & purification ; Veillonella ; isolation & purification