Xylitol-Containing Chewing Gum Reduces Cariogenic and Periodontopathic Bacteria in Dental Plaque-Microbiome Investigation

Abstract

Background: Dental caries and periodontal disease remain the most prevalent oral health problems in the world. Chewing xylitol gum may help reduce the risk of caries and periodontitis for dental health benefits. However, little evidence has shown healthy food estimation by sequencing 16S rDNA in oral microbial communities. This study investigated the clinical effect of xylitol chewing gum on dental plaque accumulation and microbiota composition using the PacBio full-length sequencing platform in 24 young adults (N = 24). The participants were randomly assigned to xylitol chewing gum and control (no chewing gum) groups. Participants in the chewing gum group chewed ten pieces of gum (a total of 6.2 g xylitol/day). Dental plaque from all teeth was collected for weighing, measuring the pH value, and analysis of microbial communities at the beginning (baseline, M0) and end of the 2-week (effect, M1) study period.

Results: The results suggested a 20% reduction in dental plaque accumulation (p < 0.05) among participants chewing xylitol gum for 2 weeks, and the relative abundance of Firmicutes (a type of pathogenic bacteria associated with caries) decreased by 10.26% (p < 0.05) and that of Bacteroidetes and Actinobacteria (two types of pathogenic bacteria associated with periodontitis) decreased by 6.32% (p < 0.001) and 1.66% (p < 0.05), respectively. Moreover, the relative abundance of Fusobacteria was increased by 9.24% (p < 0.001), which has been proven to have a higher proportion in dental plaque of healthy adults. However, the dental plaque pH value stayed in a healthy range for the two groups.

Conclusion: In conclusion, chewing xylitol gum would benefit cariogenic and periodontal bacterial reduction in the oral cavity, which could help to prevent the diseases related to these bacteria.

Keywords: 16S rDNA sequencing analysis; dental caries (DMFT); dental plaque; oral health and hygiene; oral microbiota; periodontal health; periodontopathic bacteria; xylitol gum.

FIGURE 1

Sample collection flowchart and investigation schedule for subjects. After the initial washout period, participants were randomly assigned into one of two groups (Control with no-gum chewing, xylitol gum). Supragingival dental plaque was collected at baseline and 2 weeks after the treatment period for assessment. The questionnaire was shown in Supplementary Table 1.

FIGURE 2

The average profile of OTUs of oral dental plaque at the phylum level at M0 and M1 from the (A) control group and (B) xylitol gum group.

FIGURE 3

Comparison of relative abundance at the phylum level from the xylitol gum group at M0 and M1; *p < 0.05, and ***p < 0.001 respectively, using Wilcoxon’s test.

FIGURE 4

Comparison of the relative abundance of cariogenic bacteria at the family or genus level from the xylitol gum group at M0 and M1; *p < 0.05, **p < 0.01, respectively, using Wilcoxon’s test.

FIGURE 5

Comparison of the relative abundance of periodontopathic bacteria at the family or genus level in the xylitol gum group at M0 and M1; *p < 0.05, respectively, using Wilcoxon’s test.

FIGURE 6

Comparison of the relative change in Bacteroidetes in the control and xylitol groups. The value of abundance of Bacteroidetes for M1 was divided by M0. Error bars indicate the interquartile values, and the dashed line represents the baseline (M0/M0 = 1); “*” indicates p < 0.05 when compared with the baseline using the two-tailed Wilcoxon test.

FIGURE 7

The main abundant taxa that differed before treatment (M0, baseline) and after the 2-week follow-up (M1) in the taxonomic cladogram based on Linear discriminant analysis effect size (LEfSe) analysis and its LDA score from the (A) control group (B) xylitol gum group.

FIGURE 8

A scatter plot showing the distribution between dental plaque accumulation and a total of cariogenic and periodontopathic bacteria among the (A) Xylitol and (B) Control group, showing the confidence ellipses (51). Total of cariogenic and periodontopathic bacteria and dental plaque accumulation are plotted on the horizontal and vertical axes, respectively. Each blue dots represent baseline (M0), and the orange dots represent M1.