Acidogenic fermentation of pentose alcohols by human dental plaque microorganisms.

The potential non-cariogenicity of the pentose sugar alcohols xylitol, l-arabinitol and ribitol was estimated by determining their fermenting properties with 50 separate samples of dental plaque, collected from people of different ages. Sucrose and control cultures were included for comparison. For most subjects, sucrose was more acidogenic than the pentitols. Lactobacilli or propionibacteria which fermented xylitol were isolated in pure culture from 2 out of 50 plaque samples whereas lactobacilli which fermented l-arabinitol were purified from another. Tests were made for pentitol metabolism by saliva collected from 8 subjects: 3 carried lactobacilli or propionibacteria which fermented xylitol and at least 2 contained lactobacilli that used l-arabinitol anaerobically. Candida albicans isolated from 2 subjects metabolized xylitol aerobically. Thus xylitol-utilizing oral microorganisms may be widespread. Further research is desirable before encouraging the widespread substitution of xylitol for sucrose.