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A once-annual caries preventive (Intervention) treatment was offered to Aboriginal and Torres Strait Islander schoolchildren—a population with disproportionately poorer oral health than non-Indigenous Australian children—in the Northern Peninsula Area (NPA) of Far North Queensland (FNQ), which significantly improved their oral health. Here, we examine the salivary microbiota of these children (mean age = 10 ± 2.96 years; n = 103), reconstructing the bacterial community composition with high-throughput sequencing of the V4 region of bacterial 16S rRNA gene. Microbial communities of children who received the Intervention had lower taxonomic diversity than those who did not receive treatment (Shannon, p < 0.05). Moreover, the Intervention resulted in further decreased microbial diversity in children with active carious lesions existing at the time of saliva collection. Microbial species associated with caries were detected; Lactobacillus salivarius, Lactobacillus reuteri, Lactobacillus gasseri, Prevotella multisaccharivorax, Parascardovia denticolens, and Mitsuokella HMT 131 were significantly increased (p < 0.05) in children with severe caries, especially in children who did not receive the Intervention. These insights into microbial associations and community differences prompt future considerations to the mechanisms behind caries-preventive therapy induced change; important for understanding the long-term implications of like treatment to improve oral health disparities within Australia. Trial registration: ANZCTR, ACTRN12615000693527. Registered 3 July 2015, [ABSTRACT FROM AUTHOR]

Objective: While some oral carcinomas appear to arise de novo, others develop within long-standing conditions of the oral cavity that have malignant potential, now known as oral potentially malignant disorders (OPMDs). The oral bacteriome associated with OPMD has been studied to a lesser extent than that associated with oral cancer. To characterize the association in detail we compared the bacteriome in whole mouth fluid (WMF) in patients with oral leukoplakia, oral cancer and healthy controls. Methods: WMF bacteriome from 20 leukoplakia patients, 31 patients with oral cancer and 23 healthy controls were profiled using the Illumina MiSeq platform. Sequencing reads were processed using DADA2, and taxonomical classification was performed using the phylogenetic placement method. Sparse Partial Least Squares Regression Discriminant Analysis model was used to identify bacterial taxa that best discriminate the studied groups. Results: We found considerable overlap between the WMF bacteriome of leukoplakia and oral cancer while a clearer separation between healthy controls and the former two disorders was observed. Specifically, the separation was attributed to 14 taxa belonging to the genera Megaspheara, unclassified enterobacteria, Prevotella, Porphyromonas, Rothia and Salmonella, Streptococcus, and Fusobacterium. The most discriminative bacterial genera between leukoplakia and oral cancer were Megasphaera, unclassified Enterobacteriae, Salmonella and Prevotella. Conclusion: Oral bacteria may play a role in the early stages of oral carcinogenesis as a dysbiotic bacteriome is associated with oral leukoplakia and this resembles that of oral cancer more than healthy controls. Our findings may have implications for developing oral cancer prevention strategies targeting early microbial drivers of oral carcinogenesis. [ABSTRACT FROM AUTHOR]

Background: While the patterns of consumption of areca nut and its by-products (ANBP) vary across South Asia and the rest of the world, all users share the probable severe outcome of oral submucous fibrosis (OSMF), and this is well reported. The role of psychosocial drivers of habit initiation and addiction is reported less. Objective: To reveal the burden of ANBP abuse, exploring the psychosocial relationship between sex, age at first exposure (AFE), the reason for initiation (RFI) with the type of habit (TOH). Methodology: Data came from the prospective hospital-based study conducted at K.M. Shah Dental College and Hospital covering years 2017 and 2018. Patients with oral lesions were assessed with complete history recording demographics, TOH, AFE, RFI, duration of habit, and clinical diagnosis of any oral and systemic diseases. Patients with a history of scleroderma, facial burns, and oral malignancy were excluded. Results: Of the 13,874 patients, 9.89% reported ANBP. We included 1000 OSMF patients. The mean age of the study cohort was 38.97 ± 14.29 years, with a range of 17–75 years. Males constituted the majority (80.1%). The most common TOH reported was regular use of gutkha (60.1%) followed by mawa (31.4%) with tension and stress (30.3%) being the most common RFI among the cohort. TOH was notably different in relation to AFE. Interestingly, mawa chewing (38.69%) was observed more in females. Importance: This study reveals the burden of ANBP abuse and reports the complex psychosocial relationships between sex, AFE, and RFI with TOH in OSMF patients in this high incidence population. [ABSTRACT FROM AUTHOR]

The aim of this study was to characterize the mycobiome associated with oral squamous-cell carcinoma (OSCC). DNA was extracted from 52 tissue biopsies (cases: 25 OSCC; controls: 27 intra-oral fibro-epithelial polyps [FEP]) and sequenced for the fungal internal transcribed spacer 2 region using Illumina™ 2 x300bp chemistry. Merged reads were classified to species level using a BLASTN-algorithm with UNITE’s named species sequences as reference. Downstream analyses were performed using QIIME™ and linear discriminant analysis effect size. A total of 364 species representing 160 genera and two phyla (Ascomycota and Basidiomycota) were identified, with Candida and Malassezia making up 48% and 11% of the average mycobiome, respectively. However, only five species and four genera were detected in ≥50% of the samples. The species richness and diversity were significantly lower in OSCC. Genera Candida,Hannaella, and Gibberella were overrepresented in OSCC;Alternaria and Trametes were more abundant in FEP. Species-wise, Candida albicans,Candida etchellsii, and a Hannaella luteola–like species were enriched in OSCC, while aHanseniaspora uvarum–like species,Malassezia restricta, andAspergillus tamariiwere the most significantly abundant in FEP. In conclusion, a dysbiotic mycobiome dominated by C. albicans was found in association with OSCC, a finding worth further investigation. [ABSTRACT FROM PUBLISHER]