Caries Increment and Salivary Microbiome during University Life: A Prospective Cohort Study

Abstract

The purpose of this 3-year prospective cohort study was to explore the relationship between an increase in dental caries and oral microbiome among Japanese university students. We analyzed 487 students who volunteered to receive oral examinations and answer baseline (2013) and follow-up (2016) questionnaires. Of these students, salivary samples were randomly collected from 55 students at follow-up and analyzed using next-generation sequencing. Students were divided into two groups: increased group (Δdecayed, missing, and filled teeth (ΔDMFT) score increased during the 3-year period) and non-increased group (ΔDMFT did not increase). Thirteen phyla, 21 classes, 32 orders, 48 families, 72 genera, and 156 species were identified. Microbial diversity in the increased group (n = 14) was similar to that in the non-increased group (n = 41). Relative abundances of the family Prevotellaceae (p = 0.007) and genera Alloprevotella (p = 0.007) and Dialister (p = 0.039) were enriched in the increased group compared with the non-increased group. Some bacterial taxonomic clades were differentially present between the two groups. These results may contribute to the development of new dental caries prevention strategies, including the development of detection kits and enlightenment activities for these bacteria.

Living with Family Is Directly Associated with Regular Dental Checkup and Indirectly Associated with Gingival Status among Japanese University Students: A 3-Year Cohort Study

“…In this study, analyzed students (n = 377) comprised 18.6% of all eligible students (n = 2026). The response rate in this study was within the previous prospective 3-year cohort studies in university students (13.4–25.7%) [ 32 , 33 , 40 , 41 ]. No significant differences were seen in %BOP and sex ratios between analyzed and non-analyzed students (377 vs. 1649 students; Mann–Whitney U test: p > 0.05, chi-squared test: p > 0.05).…”

“…The percentage of students who answered that they brushed their teeth more than once (87.5 %) was slightly higher than the previous cohort studies (75.0–84.7%). The percentage of students who answered they used dental floss (16.7%) was also slightly higher than the previous cohort studies (10.7–15.4%) [ 32 , 33 ].…”

“…In this study, university students’ oral health behavior tended to be better than in the previous prospective 3-year cohort studies in university students [ 32 , 33 ]. In the present study, 30.2% of students answered received regular dental checkups at follow-up.…”

Oral microbiome in down syndrome and its implications on oral health

“…The NO is produced by the same pathway of nitrate reduction by oral and airway bacteria, so increasing the nitrate intake in DS individuals may help to promote the growth of Alloprevotella and other nitrate reducers to boost the immune response, though this would require further study in the context of DS. Both Alloprevotella [ 55–57 , 103 ] and Atopobium [ 52 , 56 , 104 ] have been shown to be associated with increased incidence of dental caries, so their low abundances in DS here again support the low caries in DS seen in the literature. The lower abundance of the genus Candidatus _ Saccharimonas , of the fairly recently described Patescibacteria phylum [ 105 ], does not seem to show the same connection from the literature, as this genus [ 57 ] and its family, Saccharimonadaceae [ 106 ], were shown to be found at lower abundances in individuals with dental caries than in healthy controls.…”

Alloprevotella rava isolated from a mixed infection of an elderly patient with chronic mandibular osteomyelitis mimicking oral squamous cell carcinoma

“…Cases are usually mixed anaerobic infections, reinforcing the concept that osteomyelitis of the jaws is mainly related to microorganisms from the oral environment [ 1 ]. Alloprevotella rava is an obligatory anaerobic Gram-negative bacillus isolated from the human oral cavity, associated with oral dysbiotic infections such as dental caries and periodontitis [ [2] , [3] , [4] ]. We present the first case of A. rava infection in a patient with polymicrobial CMO initially thought to be oral squamous cell carcinoma from clinical and computed tomography findings.…”