Effect of Xylitol on Oral Microbiota in Children

Overview

1. The present controlled, randomized, doubleblind study aims to answer the following questions: * How will the "normal flora" be affected by the xylitol consumption? * Will daily consumption of xylitol change the plaque-saliva distribution of the mutans streptococci? * The association of the test results will also be compared with the caries status at the baseline. 2. About eighty subjects with MS counts of log CFU 5 or more will be identified and invited to the study. They will be randomly divided into a Xylitol and Sorbitol group. 3. Xylitol/Sorbitol gum (6g polyol/day) will be used for 5 weeks. Saliva samples will be collected before and after gum use. 4. Studying and quantifying of 16 bacterial species belonging to the normal flora by DNA-DNA hybridizations and Real-time PCR will show how xylitol influenced the oral flora in general.

Xylitol, a 5-carbon polyol, has in clinical studies prevented caries occurrence in children and decreased counts of mutans streptococci (MS) and the amount of plaque when used on daily basis. How xylitol influences mutans streptococci is far from clear. Also the effects of xylitol on the normal flora are poorly understood. The present controlled, randomized, doubleblind study aims to answer the following questions: 1. How will the "normal flora" be affected by the xylitol consumption? 2. Will daily consumption of xylitol change the plaque-saliva distribution of the mutans streptococci? 3. The association of the test results will also be compared with the caries status at the baseline. After collecting informed consent forms from the parents, about 177 children will be screened for the presence of salivary mutans streptococci (SM) with chairside test, Dentocult SM® Strip mutans (Orion Diagnostica, Finland). Sorbitol is regarded as an inert polyol. Xylitol/Sorbitol gum (6g polyol/day) will be used for 5 weeks. Saliva samples will be collected before and after gum use. Studying and quantifying of 16 bacterial species belonging to the normal flora by DNA-DNA hybridizations and Real-time PCR will show how xylitol influenced the oral flora in general. Comparison of MS counts in unstimulated vs. stimulated saliva will show how xylitol affected the adhesivity of the MS.