Bacteriome and mycobiome dysbiosis in oral mucosal dysplasia and oral cancer

It has long been considered that the oral microbiome is tightly connected to oral health and that dysbiotic changes can be detrimental to the occurrence and progression of dysplastic oral mucosal lesions or oral cancer. Improved understanding of the concepts of microbial dysbiosis together with advances in high-throughput molecular sequencing of these pathologies have charted in greater microbiological detail the nature of their clinical state. This review discusses the bacteriome and mycobiome associated with oral mucosal lesions, oral candidiasis, and oral squamous cell carcinoma, aiming to delineate the information available to date in pursuit of advancing diagnostic and prognostic utilities for oral medicine.

Gender modified association of oral health indicators with oral health-related quality of life among Korean elders

OBJECTIVE

To evaluate the association between oral health-related quality of life (OHRQoL) and oral health indicators including dental status, total occlusion force (TOF), number of natural and rehabilitated teeth (NRT), number of natural teeth (NT), and to explore the effect modification on the association by gender among Korean elders.

METHODS

A total of 675 participants aged 65 or above recruited by a cluster-based stratified random sampling were included in this cross-sectional study. The 14-items Korean version of the Oral Health Impact Profile (OHIP) was used to measure OHRQoL. The responses about OHIP were dichotomized by the cut-off point of 'fairly often' to determine the 'poor' versus 'fair' OHRQoL. Age, gender, education level, alcohol drinking, smoking, metabolic syndrome, frailty, and periodontitis were considered as confounders. Multiple multivariable logistic regression analyses were applied to assess the adjusted association between oral health indicators and OHRQoL. Gender stratified analysis was also applied to explore the effect modification of the association.

RESULTS

The prevalence of poor OHRQoL was 43.0%, which was higher in women, less-educated elders, alcohol non-drinkers and frailty elders (p < 0.05). Elders with poor OHRQoL also showed lower values of oral health indicators than elders with fair OHRQoL (p < 0.05). Those with NRT ≤ 24, NT ≤ 14, and TOF < 330 N increased the risk of poor OHRQoL by 2.3 times (OR = 2.26, confidence interval [CI] 1.54-3.31), 1.5 times (OR = 1.45, CI 1.02-2.07), and 1.5 times (OR = 1.47, CI 1.06-2.04), respectively. In women, the association of NRT ≤ 24 with poor OHRQoL increased from OR of 2.3 to OR of 2.4, while, in men, the association of TOF < 330 N with poor OHRQoL increased from OR of 1.5 to OR of 3.2.

CONCLUSION

Oral health indicators consisting of TOF, NRT, and NT were independently associated with poor OHRQoL among Korean elders. Gender modified the association of TOF and NRT. Preventive and/or curative management for keeping natural teeth and the rehabilitation of missing teeth to recover the occlusal force may be essential for reducing poor OHRQoL.

Gene signatures associated with barrier dysfunction and infection in oral lichen planus identified by analysis of transcriptomic data

Oral lichen planus (OLP) is one of the most prevalent oral mucosal diseases, but there is no cure for OLP yet. The aim of this study was to gain insights into the role of barrier dysfunction and infection in OLP pathogenesis through analysis of transcriptome datasets available in public databases. Two transcriptome datasets were downloaded from the Gene Expression Omnibus database and analyzed as whole and as partial sets after removing outliers. Differentially expressed genes (DEGs) upregulated in the dataset of OLP versus healthy epithelium were significantly enriched in epidermal development, keratinocyte differentiation, keratinization, responses to bacterial infection, and innate immune response. In contrast, the upregulated DEGs in the dataset of the mucosa predominantly reflected chemotaxis of immune cells and inflammatory/immune responses. Forty-three DEGs overlapping in the two datasets were identified after removing outliers from each dataset. The overlapping DEGs included genes associated with hyperkeratosis (upregulated LCE3E and TMEM45A), wound healing (upregulated KRT17, IL36G, TNC, and TGFBI), barrier defects (downregulated FRAS1 and BCL11A), and response to infection (upregulated IL36G, ADAP2, DFNA5, RFTN1, LITAF, and TMEM173). Immunohistochemical examination of IL-36γ, a protein encoded by one of the DEGs IL36G, in control (n = 7) and OLP (n = 25) tissues confirmed the increased expression of IL-36γ in OLP. Collectively, we identified gene signatures associated with hyperkeratosis, wound healing, barrier defects, and response to infection in OLP. IL-36γ, a cytokine involved in both wound repair and antimicrobial defense, may be a possible therapeutic target in OLP.