Purpose: Microorganisms contribute to the pathogenesis of obstructive sleep apnea (OSA)-associated hypertension (HTN), while more studies focus on intestinal microbiome. However, the relationship between oral microbiota and OSA-associated HTN has yet to be elucidated. This study aimed to identify differences in salivary microbiota between patients with OSA comorbid HTN compared with OSA patients, and furthermore evaluate the relationship between oral microbiome changes and increased blood pressure in patients with OSA. Patients and Methods: This study collected salivary samples from 103 participants, including 27 healthy controls, 27 patients with OSA, 23 patients with HTN, and 26 patients with OSA comorbid HTN, to explore alterations of the oral microbiome using 16S rRNA gene V3-V4 high-throughput sequencing. And ultra-high-performance liquid chromatography was used for metabolomic analysis. Results: Alpha- and beta-diversity analyses revealed a substantial difference in community structure and diversity in patients with OSA comorbid HTN compared with patients with OSA or HTN. The relative abundance of the genus Actinomyces was significantly decreased in patients with HTN compared with healthy controls, and those with OSA concomitant HTN compared with the patients in OSA, but was not significantly different between patients with OSA and healthy controls. Linear discriminant analysis effect size and variance analysis also indicated that the genera Haemophilus, Neisseria, and Lautropia were enriched in HTN. In addition, Oribacterium was an unique taxa in the OSA comorbid HTN group compared with the control group. Metabolomic analysis of saliva identified compounds associated with cardiovascular disease in patients with OSA comorbid HTN.2-hydroxyadenine, was significantly increased in the group of patients with OSA compared with controls, and L-carnitine was significantly decreased in patients with OSA comorbid HTN compared with OSA patients. Conclusion: This study highlighted noninvasive biomarkers for patients with OSA comorbid HTN. As the first study to find alterations of the salivary microbiome in patients with OSA comorbid HTN, it may provide a theoretical foundation for clinical diagnosis and treatment of this condition.

Objectives: To evaluate the effect of stem cells from exfoliated deciduous teeth on the hyposalivation caused by Sjögren syndrome (SS) and investigate the mechanism.Methods: Stem cells were injected into the tail veins of non‐obese diabetic mice, the animal model of SS. The saliva flow was measured after pilocarpine intraperitoneal injection. Apoptosis and autophagy were evaluated by TUNEL and Western blot. Lymphocyte proportions were detected by flow cytometer.Results: Fluid secretion was decreased in 21‐week‐old mice. Stem cell treatment increased fluid secretion, alleviated inflammation in the submandibular glands and reduced inflammatory cytokine levels in the serum, submandibular glands and saliva. Stem cells decreased the apoptotic cell number and the expressions of ATG5 and Beclin‐1 in the submandibular glands. Stem cells have no effect on other organs. Furthermore, the infused stem cells migrated to the spleen and liver, not the submandibular gland. Stem cells directed T cells towards Treg cells and suppressed Th1 and Tfh cells in spleen lymphocytes.Conclusion: Stem cells from exfoliated deciduous teeth alleviate the hyposalivation caused by SS via decreasing the inflammatory cytokines, regulating the inflammatory microenvironment and decreasing the apoptosis and autophagy. The stem cells regulated in T‐cell differentiation are involved in the immunomodulatory effects.

Background. Oral microbiota plays an important role in oral and systemic diseases, while few reports referred to obstructive sleep apnea syndrome (OSAS). Thus, this study aimed to explore the different salivary microbiome in patients with OSAS and controls. Materials and Methods. Saliva was collected from 15 OSAS patients and nine healthy controls, and bacterial genomic DNA was extracted for 16S rRNA amplicon sequencing based on the Illumina platform. Results. The alpha and beta diversities were not significantly different between patients with OSAS and controls. The main phyla in the two groups were Firmicutes, Actinobacteria, Bacteroidetes, Proteobacteria, and Fusobacteria, which accounted for 95 of the abundance. The main genera were Streptococcus, Rothia, Actinomyces, Prevotella, and Neisseria. Based on the genus and operational taxonomic units, Peptostreptococcus, Alloprevotella, and Granulicatella were enriched in controls, while only Scardovia species were significantly more abundant in patients with OSAS. Conclusions. There was no significant difference in the relative abundance of bacteria between OSAS and controls. So, further studies will need to focus on the metagenome of bacteria in OSAS patients.

Antibiotic resistance, is often conferred by the presence of antibiotic resistance genes. This study aimed to investigate the relationship between tetracycline resistance (Tet-R) and genotype in 31 Lactobacillus isolates from caries-active patients. The tetracycline susceptibility of Lactobacillus isolates was determined using the agar spot test and the genetic characteristics associated with tetracycline resistance using whole-genome sequencing (WGS). The minimum inhibitory concentration (MIC) values of most isolates were equal to or lower than the breakpoint MIC values. Four strains that were phenotypically more sensitive (L. fermentum B09, S23 and L. rhamonsus B17) or more resistant (L. plantarum B43) than other isolates to tetracycline were subjected to conduct whole-genome sequencing in order to detect the tetracycline resistance genes. The results revealed that the most common Tet-R genes in Lactobacillus strains were tetT, tetW, tetO and tetL. In addition, tetPB, tcr3 and otrA were detected for the first time. There were distinct Tet-R gene mutations in Lactobacillus isolates. Overall, the mean expression values of Tet-R-mutated genes in L. plantarum B43 were elevated, and the relative expression levels of tetT and tetW genes in L. rhamonsus B17 L. fermentum B09 and S23 were decreased relative to reference strains. The results of this study indicate that Lactobacillus isolates from saliva of caries-active patients do not present considerable tetracycline resistance reservoirs. However, genetic compounds associated with tetracycline resistance were identified by whole-genome sequencing, providing meaningful insights into tetracycline resistance mechanisms.