Cariogenic and oral health taxa in the oral cavity among children and adults: A scoping review

Abstract

Objective: To review published oral microbiome studies and create a comprehensive list of bacterial species found in saliva and dental plaque among healthy children and adults associated with presence of carious lesions and caries-free state (oral health).

Design: This review followed PRISMA-ScR guidelines. We searched published studies querying PUBMED and EMBASE using the following keywords: (plaque OR saliva) AND caries AND (next generation sequencing OR checkerboard OR 16s rRNA or qPCR). Studies were limited to human studies published in English between January 1, 2010 and June 24, 2020 that included > 10 caries-active and > 10 caries-free participants, and assessed the entire bacterial community.

Results: Our search strategy identified 298 articles. After exclusion criteria, 22 articles remained; we considered 2 studies that examined saliva and plaque as separate studies, for a total of 24 studies. Species associated with caries or oral health varied widely among studies reviewed, with notable differences by age and biologic sample type. No bacterial species was associated with caries in all studies. Streptococcus mutans was found more frequently among those with caries (14/24 (58.3 %)) and Fusobacterium periodonticum was found more frequently among those that were caries-free (5/24 (20.8 %)).

Conclusion: No bacterial species was associated with caries or oral health across all studies supporting multiple pathways to cariogenesis. However, the variation may be due to sampling at different time points during caries development, varying methods of specimen sampling, storage, sequencing or analysis or differences in host factors such as age.

Keywords: 16S rRNA; Dental caries; Oral microbiome.

Figure 1.

Schematic diagram depicting literature search process for oral microbiome studies conducted in the past 10 years from EMBASE and PUBMED. *Two studies that included saliva and plaque sample were treated as two separate studies each

Figure 2.

Number of studies that found statistically significant taxa identified as cariogenic (red) or oral health (green) from the total 24 studies found eligible in this scoping review, stratified by sample type and age group. Studies that looked at plaque in adults (n = 3), plaque in children (n = 9), saliva in adults (n = 4), saliva in children (n = 8). Note: Only taxa that were found to be statistically significant in at least 2/24 studies are presented.