Influence of the long-term use of oral hygiene products containing stannous ions on the salivary microbiome - a randomized controlled trial

Abstract

Oral hygiene products containing tin are suitable to prevent erosive tooth wear, yet effects on the oral microbiota are not known yet. Therefore, this study determined the salivary microbiome of 16 participants using products with stannous ions for three years (TG) compared with a control group (CG) to assess their influence on the microbiota. Participants were included in a randomized controlled clinical trial (RCT) with biannual visits. Illumina Miseq sequencing revealed as most abundant genera: Streptococcus (TG 14.3%; CG 13.0%), Veillonella (TG 11.3%; CG 10.9%), Prevotella (TG 7.0%; CG 9.8%), Haemophilus (TG 6.6%; CG 7.2%), Porphyromonas (TG 5.9%, CG 5.1%), Leptotrichia (TG 5.8%; CG 4.9%), Actinomyces (TG 4.0%; CG 4.6%) and Neisseria (TG 5.4%; CG 4.2%). Beta-Diversity was not significantly different between groups at both time points, although significant differences between groups were found for certain taxa after three years. The genus Prevotella was found in higher abundance in CG whereas Neisseria and Granulicatella, health-associated taxa, were found more abundantly in TG. Salivary microbiota after three years reflected a composition associated with oral health, hence continual use as a preventive measure for dental erosion can be considered safe and benefitting oral health for patients with a high risk of erosion.

Figure 1

(a) Relative abundances of the top six phyla (>1% abundance) detected in saliva in TG (Treatment group, blue) and CG (Control group, red) (*p ≤ 0.05) (b) Relative abundance of the bacterial genera detected in saliva in CG, (c) Relative abundance of the bacterial genera detected in saliva in TG, (d) Relative abundances of the genera Prevotella, Neisseria and Granulicatella in CG and TG, (e) Relative abundances of the different Prevotella species (>1% abundance) in TG (blue) and CG (red), (*p ≤ 0.05).

Figure 2

NMDS plot (non-metric multidimensional scaling) depicting the beta-diversity of the microbiota in saliva in CG and TG (Zymo Research Data).

Figure 3

Bar graph of LEfSe analysis of bacterial taxa in saliva in CG (red) and TG (blue) showing LDA scores (Biomarkers sorted according to effect size).

Figure 4

Relative abundances of the different Prevotella species (>1% abundance) in saliva of both groups related to the gender of the study participants (green = men, orange = women), (*p ≤ 0.05).