Compositional shifts within the denture-associated bacteriome in pneumonia - an analytical cross-sectional study

• Published in: Journal of medical microbiology Vol. 72; no. 6
• Main Authors: Twigg, Joshua A, Smith, Ann, Haury, Clotilde, Wilson, Melanie J, Lees, Jonathan, Waters, Mark, Williams, David W
• Format: Journal Article
• Language: English
• Published: England 01.06.2023
• Subjects: bacteriome; 16S rRNA; bacterial pneumonia; denture; metataxonomic sequencing
• ISSN: 0022-2615; 1473-5644
• DOI: 10.1099/jmm.0.001702

Bacterial pneumonia is a common cause of morbidity and mortality in elderly individuals. While the incidence of edentulism is falling, approximately 19 % of the UK population wear a full or partial removable denture. Despite advances in denture biomaterials, the majority of dentures are fabricated using polymethyl-methacrylate. Growing evidence suggests that colonization of the oral cavity by putative respiratory pathogens predisposes individuals to respiratory infection, by translocation of these microorganisms along the respiratory tract. We hypothesized that denture surfaces provide a susceptible colonization site for putative respiratory pathogens, and thus could increase pneumonia risk in susceptible individuals. This study aimed to characterize the bacterial community composition of denture-wearers in respiratory health compared with individuals with a confirmed diagnosis of pneumonia. This was an analytical cross-sectional study, comparing frail elderly individuals without respiratory infection ( =35) to hospitalized patients with pneumonia ( =26). The primary outcome was the relative abundance of putative respiratory pathogens identified by 16S rRNA metataxonomic sequencing, with quantitative PCR used to identified . There was a statistically significant increase in the overall relative abundance of putative respiratory pathogens ( <0.0001), with a greater than 20-fold increase in the bioburden of these microorganisms. In keeping with these findings, there were significant shifts in bacterial community diversity (Chao index, =0.0003) and richness (Inverse Simpson index <0.0001) in the denture-associated microbiota of pneumonia patients compared with control subjects. Within the limitations of this study, our evidence supports the role of denture acrylic biomaterials as a potential colonization site for putative respiratory pathogens, which may lead to an increased risk of pneumonia in susceptible individuals. These findings support prior observational studies which have found denture-wearers to be at increased risk of respiratory infection. Further research is needed to confirm the sequence of colonization and translocation to examine potential causal relationships.