Association between oral frailty and Prevotella percentage in the oral microbiota of community-dwelling older adults who participated in the CHEER Iwamizawa project, Japan.

BACKGROUND: Prevotella bacteria are associated with inherent diseases of the oral cavity, such as periodontal disease, and systemic diseases. Oral frailty (OF) has been associated with nursing necessity and death. However, the relationship between OF and oral microbiota has not been fully clarified. OBJECTIVE: This cross-sectional study investigated the association between OF and Prevotella percentage in the oral microbiota of community-dwelling older adults. METHODS: Oral bacteria species from saliva were identified in 208 community-dwelling older individuals aged ≥60 years in Japan. The proportion of Prevotella in the oral microbiota was classified into three tertile groups, and its relationship with each test item for OF (number of remaining teeth, masticatory performance, oral diadochokinesis, tongue pressure, difficulties eating tough foods, difficulties swallowing tea or soup, number of applicable OF judgement items, and existence of OF) was examined using ordinal logistic regression analysis. RESULTS: The Prevotella proportions were classified into lower, middle and upper groups, comprising 70, 69 and 69 participants, respectively. The three groups showed a significant relationship between the number of remaining teeth (odds ratio [OR]: 0.946, 95% confidence interval [CI]: 0.915-0.977), masticatory performance (OR: 0.897, 95% CI: 0.844-0.953), number of applicable OF judgement items (OR: 1.477, 95% CI: 1.14-1.915), and existence of OF (OR: 4.194, 95% CI: 1.519-11.576). CONCLUSION: The proportion of Prevotella in oral microbiota was high in individuals with OF. Among the older adults, the type of oral microbiota and systemic diseases may be related to the examination and management of oral function decline.

Oral frailty and carriage of oral Candida in community-dwelling older adults (Check-up to discover Health with Energy for senior Residents in Iwamizawa; CHEER Iwamizawa).

OBJECTIVE: To examine the association between oral frailty and oral Candida carriage as a general indicator of deteriorating oral function in older adults. BACKGROUND: Older adults exhibit an elevated risk of oral candidiasis caused by Candida. Although many studies have identified factors associated with oral Candida carriage, none have evaluated its relationship with oral function. MATERIALS AND METHODS: This study included 210 community-dwelling older adults aged ≥60 years who participated in wellness checks. Fungal flora expression in saliva samples was evaluated to identify oral C. albicans and C. glabrata. Participants were categorised by detection of neither strain (group 1), either one of the strains (group 2), or both strains (group 3). The relationship between oral Candida carriage and oral frailty was evaluated by multinomial logistic regression analysis. RESULTS: The participants included 58 men and 152 women with a mean age of 74.2 ± 6.1 years. A total of 88 (41.9%), 94 (44.8%) and 28 (13.3%) participants were assigned to groups 1, 2 and 3 respectively. In the multinomial logistic regression analysis, significant associations were observed between group 1 and group 2 for "Have you choked on your tea or soup recently?" and the number of applicable oral frailty items. Between group 1 and group 3, significant associations were observed for the number of remaining teeth, masticatory performance and the number of applicable oral frailty items. CONCLUSION: We obtained basic data useful for intervention studies aimed at verifying whether oral function management prevents deterioration of the oral bacterial flora.

Development of Autopolymerizing Resin Material with Antimicrobial Properties Using Montmorillonite and Nanoporous Silica.

Although autopolymerizing resin offers numerous applications in orthodontic treatment, plaque tends to accumulate between the appliance and the mucosa, which increases the number of microorganisms present. In this study, we added cetylpyridinium chloride (CPC) loaded montmorillonite (Mont) and nanoporous silica (NPS) to autopolymerizing resin (resin-Mont, resin-NPS) and evaluated their drug release capacity, antimicrobial capacity, drug reuptake capacity, mechanical strength, and color tone for the devolvement of autopolymerizing resin with antimicrobial properties. As observed, resin-Mont and resin-NPS were capable of the sustained release of CPC for 14 d, and a higher amount of CPC was released compared to that of resin-CPC. Additionally, resin-Mont and resin-NPS could reuptake CPC. Moreover, the antimicrobial studies demonstrated that resin-Mont and resin-NPS could release effective amounts of CPC against Streptococcus mutans for 14 d and 7 d after reuptake, respectively. Compared to resin-CPC, resin-Mont exhibited a higher sustained release of CPC in all periods, both in the initial sustained release and after reuptake. However, the mechanical strength decreased with the addition of Mont and NPS, with a 36% reduction observed in flexural strength for resin-Mont and 25% for resin-NPS. The application of these results to the resin portion of the orthodontic appliances can prevent bacterial growth on the surface, as well as on the interior, of the appliances and mitigate the inflammation of the mucosa.

Factor associated with oral candidiasis caused by co-infection of Candida albicans and Candida glabrata: A retrospective study.

This study aimed to determine the factors associated with the co-infection of Candida albicans and Candida glabrata. This retrospective study conducted between January 2015 and 2020 comprised 131 patients who were diagnosed with oral candidiasis. The factors associated with this condition were analyzed by univariate and multivariate logistic regression. Age and denture use were identified as significant risk factors in the univariate analysis. The multivariate logistic regression analysis revealed that denture use (odds ratio [OR], 8.44 95% confidence interval [CI], 1.99-28.3) and immunosuppressive therapy (OR, 9.20; 95% CI, 1.19-62.0) had significant effects on co-infection with the two Candida species. These findings suggest that immunosuppressive therapy using and dentures is significantly associated with oral candidiasis caused by co-infection of C. albicans and C. glabrata.

Signaling pathways induced by lipoproteins derived from Mycoplasma salivarium and a synthetic lipopeptide (FSL-1) in normal human gingival fibroblasts.

Lipoproteins derived from Mycoplasma salivarium and a synthetic lipopeptide (FSL-1) activate human gingival fibroblasts to induce IL-6 production and ICAM-1 expression. Human gingival fibroblasts were treated with lipoproteins or FSL-1 and then examined for the activation of mitogen-activated protein kinases (MAPKs), ERK1/2, p38, and SAPK/JNK, and transcription factors, AP-1 and NF-kappaB. Western blotting indicated that p38 and SAPK/JNK were activated in response to the stimulators, but the activation of ERK1/2 could not be discriminated because ERK1/2 was activated in the absence of stimulators. The p38 inhibitor SB 203580 also suppressed their IL-6 production-inducing activities, whereas the ERK1/2-activating MAPK kinase (MEK1) inhibitor PD 98059 did not suppress their activities. Moreover, they were capable of inducing the activation of AP-1 and NF-KB. NF-kappaB activation was also confirmed by the phosphorylation of IkappaB-alpha. On the basis of these results, it was concluded that lipoproteins of M. salivarium and FSL-1 are capable of activating the MAPKs p38 and SAPK/JNK and the transcriptional factors AP-1 and NF-kappaB in human gingival fibroblasts.

Biological activities of Bacteroides forsythus lipoproteins and their possible pathological roles in periodontal disease.

Bacteroides forsythus is a gram-negative, anaerobic, fusiform bacterium and is considered to be an etiological agent in periodontal disease. A lipoprotein fraction prepared from B. forsythus cells by Triton X-114 phase separation (BfLP) activated human gingival fibroblasts and a human monocytic cell line, THP-1, to induce interleukin-6 production and tumor necrosis factor alpha production. BfLP was found to be capable of inducing nuclear factor-kappaB translocation in human gingival fibroblasts and THP-1 cells. By using Chinese hamster ovary K1 cells transfected with Toll-like receptor genes together with a nuclear factor-kappaB-dependent CD25 reporter plasmid, it was found that signaling by BfLP was mediated by Toll-like receptor 2 but not by CD14 or Toll-like receptor 4. BfLP induced apoptotic cell death in human gingival fibroblasts, KB cells (an oral epithelial cell line), HL-60 cells (a human myeloid leukemia cell line), and THP-1 cells but not in MOLT4 cells (a T-cell leukemia cell line). Caspase-8, an initiator caspase in apoptosis, was found to be activated in these cells in response to BfLP stimulation. Thus, this study suggested that BfLP plays some etiological roles in oral infections, especially periodontal disease, by induction of cell activation or apoptosis.

Relationship between structures and biological activities of mycoplasmal diacylated lipopeptides and their recognition by toll-like receptors 2 and 6.

The lipopeptide FSL-1 [S-(2,3-bispalmitoyloxypropyl)-Cys-Gly-Asp-Pro-Lys-His-Pro-Lys-Ser-Phe, Pam(2)CGDPKHPKSF] synthesized on the basis of the N-terminal structure of a Mycoplasma salivarium lipoprotein capable of activating normal human gingival fibroblasts to induce the cell surface expression of ICAM-1 revealed an activity to induce production of monocyte chemoattractant protein 1, interleukin-6 (IL-6), and IL-8. FSL-1 also activated macrophages to produce tumor necrosis factor alpha as the Mycoplasma fermentans-derived lipopeptide MALP-2 (Pam(2)CGNNDESNISFKEK), a potent macrophage-activating lipopeptide, did. The level of the activity of FSL-1 was higher than that of MALP-2. This result suggests that the difference in the amino acid sequence of the peptide portion affects the activity because the framework structure other than the amino acid sequence of the former is the same as that of the latter. To determine minimal structural requirements for the activity of FSL-1, the diacylglyceryl Cys and the peptide portions were examined for this activity. Both portions did not reveal the activity. A single amino acid substitution from Phe to Arg and a fatty acid substitution from palmitic acid to stearic acid drastically reduced the activity. Similar results were obtained in measuring the NF-kappaB reporter activity of FSL-1 to human embryonic kidney 293 cells transfected with Toll-like receptor 2 and 6, together with a NF-kappaB-dependent luciferase reporter plasmid. These results suggest that both the diacylglyceryl and the peptide portions of FSL-1 are indispensable for the expression of biological activities and for the recognition by Toll-like receptors 2 and 6 and that the recognition of FSL-1 by Toll-like receptors 2 and 6 appears to be hydrophobic.