Oral specimens as a tool for accurate metagenomic analysis: A pilot study.

OBJECTIVES: Acute oral mucosal damage, as well as other inflammatory processes seem to be related to dysbiosis of the oral microbiome. The need to study changes in the oral microbiome led us to hypothesize what type of sample would provide the most representative picture of the entire human oral microbiome. MATERIALS AND METHODS: An observational, and cross-sectional study was carried out. Six healthy adult participants provided 3 different sample types each, that included saliva, oral rinse and mucosal biopsy tissue. We performed 16S rRNA sequencing of the V3-V4 region of the 18 samples using Illumina MiSeq technology. RESULTS: Participants were 27 ± 6,3 years old. Bacterial alpha diversity was higher in oral rinse samples compared to whole unstimulated saliva and oral mucosa tissue (p = 0,005). However, saliva specimens showed a 56 % relative abundance of identified species followed by a 30 % in oral rinse and only 1 % in tissue samples. CONCLUSIONS: This study found differences on oral microbiome composition for each type of sample. Oral rinse should be chosen when higher alpha diversity is needed, whereas whole unstimulated saliva should be more appropriate for larger amount of bacterial DNA. CLINICAL RELEVANCE: The results obtained demonstrate the importance of a correct choice of the optimal type of oral sample for microbiome studies due to the differences found in its composition.

Prevalence of acute oral mucosal damage secondary to the use of systemic antineoplastics: A systematic review and meta-analysis.

OBJECTIVE: The aim of this study was to determine the prevalence of acute oral mucosal toxicities in non-irradiated patients treated with systemic antineoplastics agents. The secondary objective was to find out differences in its prevalence among the different types of systemic antineoplastics. STUDY DESIGN: A systematic review and meta-analysis was performed. Articles from 2010 to July 2022 were retrieved and included if patients were adults undergoing oral assessment after administration of commercially available systemic antineoplastics. Data was extracted and pooled proportions were estimated using random-effect model method (Der Simonian and Lair). RESULTS: Eighty-two articles were included in the study. The overall prevalence of acute oral mucosal damage across studies was 38.2% (95% CI: 33.1%-43.3%). The prevalence was 42.9% (95% CI: 32.8%-53%) in patients treated with chemotherapy alone, 38% (95% CI: 29.1%-47%) in patients treated with a combination of chemotherapy and targeted therapies, and 32.1% (95% CI: 26.8%-37.5%) in targeted therapies alone-treated patients. No statistically significant differences were found in the prevalence of oral mucosal toxicities between the different types of systemic antineoplastic treatments. CONCLUSIONS: Oral mucosal toxicity is a major side effect in non-irradiated cancer patients undergoing systemic antineoplastics.