Effects of 4-week xylitol tablet intake on tongue microbiota composition in children: a single-arm pilot study

Xylitol helps reduce the levels of mutans streptococci in the oral cavity and the acidogenicity of dental plaque. This single-arm interventional pilot study investigated the effect of 4-week xylitol tablet intake on tongue microbiota composition in children. Tongue coating samples were collected during four visits, at 4-week intervals, from 23 orally healthy children aged 4-5 years, who consumed three xylitol tablets per day during the intervention period, and their bacterial composition was determined using 16S rRNA gene amplicon sequencing. The tongue microbiota shift during the intervention period was compared with that during the pre-intervention period without intake. A significantly greater microbiota shift, as measured by the Aitchison distance, was observed during the intervention period than during the pre-intervention period (P < 0.05, Wilcoxon signed-rank test). Following the intervention period, we detected significant reductions in the relative abundances of Prevotella jejuni and Leptotrichia HMT-417, whereas a significant increase in the relative abundance of Granulicatella adiacens was noted. No significant difference was observed in their relative abundances before and after the follow-up period, suggesting that the effect of xylitol tablet intake persisted for four weeks after quitting the intake. These results suggest a possibility that continuous intake of xylitol tablets helps alter the tongue microbiota composition.

Xylitol reportedly has beneficial effects on the maintenance of oral health, including the prevention of dental caries. This study focused on the effects of a 4-week xylitol tablet intake on tongue microbiota composition in children aged 4-5 years. Our results demonstrated greater changes in the bacterial composition during four weeks with xylitol tablet intake compared to those without the intake, characterized by relative abundance increases of oral health-associated taxa, such as Granulicatella adiacens. The results of this study suggest that continuous intake of xylitol tablets may contribute to the alteration of tongue microbiota composition to a healthy pattern.

This study is registered with the UMIN Clinical Trials Registry (UMIN-CTR) as UMIN000051982.