Introduction: Dental caries is a preventable chronic disease whereby identification of risk factors will facilitate preventive measures. This study aims to determine the level of oral health literacy (OHL), self-care practices (SCP), salivary parameters and ascertain its assocation with caries status amongst the undergraduates in IMU University. Methods: Levels of OHL (Knowledge-OHL, dental services utilisation, and label reading habit) and SCP were assessed through a self-administered questionnaire. Chairside saliva kits were used to measure the salivary parameters whilst clinical examination was performed to assess caries status. Independent T-test and Analysis of Variance (ANOVA) was used to compare differences between sex and courses respectively for measures of interest (OHL, SCP, salivary parameters, and caries status) whereas bivariate correlation with Pearsons’s coefficient was performed to examine their association with caries status. Results: The participants (n=132) had a mean Knowledge-OHL score of 23.75±8.09 with no significant difference between sex (females, 24.01±8.51; males, 23.48±7.69; p=0.15). Dentistry students had significantly higher Knowledge-OHL score than students of all other courses (p=0.01). The mean SCP score was 20.19±3.16 whereas mean DMFT was 2.32 ±3.14. All participants had healthy saliva parameters. Caries status was significantly correlated with Knowledge-OHL score (p=0.02, r=-0.18), dental services utilisation (p=0.04, r=-0.15) but not with label reading habit (p=0.78, r=0.03), SCP (p=0.30, r=-0.05) and all salivary parameters. Conclusion Knowledge-OHL and oral health services utilisation are significantly associated with oral health status
Dental Caries ; Health Literacy ; Oral Health ; Saliva ; Self Care

The reduction of nitrate to nitrite by the oral microbiota has been proposed to be important for oral health and results in nitric oxide formation that can improve cardiometabolic conditions. Studies of bacterial composition in subgingival plaque suggest that nitrate-reducing bacteria are associated with periodontal health, but the impact of periodontitis on nitrate-reducing capacity (NRC) and, therefore, nitric oxide availability has not been evaluated. The current study aimed to evaluate how periodontitis affects the NRC of the oral microbiota. First, 16S rRNA sequencing data from five different countries were analyzed, revealing that nitrate-reducing bacteria were significantly lower in subgingival plaque of periodontitis patients compared with healthy individuals (P < 0.05 in all five datasets with n = 20-82 samples per dataset). Secondly, subgingival plaque, saliva, and plasma samples were obtained from 42 periodontitis patients before and after periodontal treatment. The oral NRC was determined in vitro by incubating saliva with 8 mmol/L nitrate (a concentration found in saliva after nitrate-rich vegetable intake) and compared with the NRC of 15 healthy individuals. Salivary NRC was found to be diminished in periodontal patients before treatment (P < 0.05) but recovered to healthy levels 90 days post-treatment. Additionally, the subgingival levels of nitrate-reducing bacteria increased after treatment and correlated negatively with periodontitis-associated bacteria (P < 0.01). No significant effect of periodontal treatment on the baseline saliva and plasma nitrate and nitrite levels was found, indicating that differences in the NRC may only be revealed after nitrate intake. Our results suggest that an impaired NRC in periodontitis could limit dietary nitrate-derived nitric oxide levels, and the effect on systemic health should be explored in future studies.
Humans ; Nitrates ; Nitric Oxide ; Nitrites ; RNA, Ribosomal, 16S/genetics* ; Periodontitis/microbiology* ; Bacteria ; Dental Plaque/microbiology* ; Saliva/microbiology* ; Microbiota/genetics*

Objective: To detect and analyze the characteristics of oral microbiota in species composition, function and metabolism among caries, periodontitis and oral healthy individuals, hunting for the microbiome-derived biomarkers with specificity and sensitivity to estimate the occurrence of these two diseases. Methods: Saliva samples were collected from 10 patients with high caries risk [decayed-missing-filled teeth (DMFT)≥6, HC group] in Department of Endodontics, 10 patients with periodontitis of grade Ⅱ A-Ⅲ C (PG group) in Department of Periodontology and 10 oral healthy individuals (HH group) from School of Stomatology, The Fourth Military Medical University during from March 2022 to June 2022. A baseline examination was conducted on all participants, including their oral conditions of caries and periodontal health. Metagenomic sequencing (Illumina PE150 platform) and liquid chromatography-mass spectrometry were used to detect microorganisms and their metabolites in the samples respectively. The sequencing data were analyzed to obtain the information of microbial taxonomic composition, functional genes and metabolites in each group of samples. The basic oral conditions and saliva samples of subjects in each group were evaluated and collected by the same professional endodontist. Results: There were no significant difference in baseline characteristics such as age and sex among the subjects in each group (P>0.05). DMFT in HC group (9.0±1.7) was significantly higher than that in HH group (0) and PG group (0) (F=243.00, P<0.001). Sequencing data analysis showed that the taxonomic compositions of salivary microbiota in each group were mainly Firmicutes, Bacteroidetes, Proteobacteria, Actinobacteria and Fusobacteria at the phylum level, and Streptococcus, Neisseria, Rothia, Prevotella at the genus level. Differential analysis showed that, compared with the HH group, HC group and PG group had significant differences in taxonomic composition (P<0.05), and the most significant among them was Prevotella. At the species level, Prevotella pallens was the most significant change in HC group, and Porphyromonas gingivalis in PG group. Metabolite analysis showed that there were significant differences in metabolites between HC group and PG group. The results showed that, compared with the HH group, the most significant metabolite change was 3-hydroxy-1, 5-diphenylpentan-1-one in HC group (P=0.001) and N1 acetylspermine in PG group (P=0.002) respectively. Compared with the PG group, the metabolite of HC group with the most significant difference is D-glucosamine 6-phosphate (P=0.006). The metabolism gene function analysis showed that, the enrichment of carbohydrate metabolism related genes was highest in HC group, followed with HH group, and it was lowest in PG group. In addition, compared with the HH group, the abundance of functional genes related to glucose metabolism, such as ABC transporter and phosphotransferase system, were significantly decreased in PG group (P<0.05), but significantly increased in HC group (P<0.05). Conclusions: There is a significant correlation between the alternation of carbohydrate metabolism of salivary microbiota with the occurrence of caries and periodontitis. In the future, Prevotella pallens and 3-hydroxy-1, 5-diphenylpentan-1-one may be the potential biomarkers of caries; while Porphyromonas gingivalis and N1 acetylspermine work in the predictions of periodontitis.
Humans ; Saliva/microbiology* ; Dental Caries Susceptibility ; Periodontitis/microbiology* ; Microbiota/genetics* ; Porphyromonas gingivalis/genetics* ; RNA, Ribosomal, 16S/genetics*

Saliva testing is a vital method for clinical applications, for its noninvasive features, richness in substances, and the huge amount. Due to its direct anatomical connection with oral, digestive, and endocrine systems, clinical usage of saliva testing for these diseases is promising. Furthermore, for other diseases that seeming to have no correlations with saliva, such as neurodegenerative diseases and psychological diseases, researchers also reckon saliva informative. Tremendous papers are being produced in this field. Updated summaries of recent literature give newcomers a shortcut to have a grasp of this topic. Here, we focused on recent research about saliva biomarkers that are derived from humans, not from other organisms. The review mostly addresses the proceedings from 2016 to 2022, to shed light on the promising usage of saliva testing in clinical diagnostics. We recap the recent advances following the category of different types of biomarkers, such as intracellular DNA, RNA, proteins and intercellular exosomes, cell-free DNA, to give a comprehensive impression of saliva biomarker testing.
Humans ; Saliva/metabolism* ; Biomarkers/metabolism* ; RNA ; Exosomes/metabolism*

Objective: To investigate the characteristics of salivary microbiota in patients with laryngopharyngeal reflux (LPR). Methods: A case-control study was applied to enroll 60 patients and healthy subjects who were outpatients of the Department of Otorhinolaryngology Head and Neck Surgery of the Eighth Medical Center of the PLA General Hospital from December 2020 to March 2021, including 35 males and 25 females, aged from 21 to 80 (33.75±11.10) years. Thirty patients with suspected laryngopharyngeal reflux were selected as study group and thirty healthy volunteers without pharyngeal symptoms were selected as control group. Their salivary samples were collected, and the salivary microbiota was detected and analyzed by 16S rDNA sequencing. SPSS 18.0 software was used for statistical analysis. Results: There was no significant difference in the diversity of salivary microbiota between the two groups. At the phylum classification level, the relative abundance of Bacteroidetes in the study group was higher than that in the control group[37.86(31.15, 41.54)% vs 30.24(25.51, 34.18)%,Z=-3.46,P<0.01]. And the relative abundance of Proteobacteria in the study group was lower than that in the control group [15.76(11.81, 20.17)% vs 20.63(13.98, 28.82)%, Z=-1.98,P<0.05]. At the genus level, the relative abundance of Prevotella, Lactobacillus, Parascardovia and Sphingobium in the study group was higher than that in the control group(Z values were-2.92, -2.69, -2.05, -2.31, respectively, P<0.05).And the relative abundance of Streptococcus, Cardiobacterium, Klebsiella and Uruburuella of study group was lower than that of control group(Z values were -2.43, -2.32, -2.17, -2.32, respectively, P<0.05). LEfSe difference analysis showed that there were 39 bacteria with significant differences between the two groups, including Bacteroidetes, Prevotellaceae and Prevotella, which were enriched in the study group, and Streptococcaceae, Streptococcus and other taxa, which were enriched in the control group(P<0.05). Conclusion: The changes of the microflora in the saliva between LPR patients and healthy people suggest that the dysbacteriosis might exist in LPR patients, which may play an important role in the pathogenesis and development of LPR.
Male ; Female ; Humans ; Laryngopharyngeal Reflux/diagnosis* ; Case-Control Studies ; Microbiota ; Outpatients ; Saliva/microbiology*

OBJECTIVES: To establish the menstrual blood identification model based on Naïve Bayes and multivariate logistic regression methods by using specific mRNA markers in menstrual blood detection technology combined with statistical methods, and to quantitatively distinguish menstrual blood from other body fluids. METHODS: Body fluids including 86 menstrual blood, 48 peripheral blood, 48 vaginal secretions, 24 semen and 24 saliva samples were collected. RNA of the samples was extracted and cDNA was obtained by reverse transcription. Five menstrual blood-specific markers including members of the matrix metalloproteinase (MMP) family MMP3, MMP7, MMP11, progestogens associated endometrial protein (PAEP) and stanniocalcin-1 (STC1) were amplified and analyzed by electrophoresis. The results were analyzed by Naïve Bayes and multivariate logistic regression. RESULTS: The accuracy of the classification model constructed was 88.37% by Naïve Bayes and 91.86% by multivariate logistic regression. In non-menstrual blood samples, the distinguishing accuracy of peripheral blood, saliva and semen was generally higher than 90%, while the distinguishing accuracy of vaginal secretions was lower, which were 16.67% and 33.33%, respectively. CONCLUSIONS The mRNA detection technology combined with statistical methods can be used to establish a classification and discrimination model for menstrual blood, which can distignuish the menstrual blood and other body fluids, and quantitative description of analysis results, which has a certain application value in body fluid stain identification.
Female ; Humans ; RNA, Messenger/metabolism* ; Bayes Theorem ; Logistic Models ; Menstruation ; Body Fluids ; Saliva ; Semen ; Forensic Genetics/methods*

OBJECTIVES: To explore the feasibility of genetic marker detection of semen-specific coding region single nucleotide polymorphism (cSNP) based on SNaPshot technology in semen stains and mixed body fluid identification. METHODS: Genomic DNA (gDNA) and total RNA were extracted from 16 semen stains and 11 mixtures composed of semen and venous blood, and the total RNA was reverse transcribed into complementary DNA (cDNA). The cSNP genetic markers were screened on the validated semen-specific mRNA coding genes. The cSNP multiplex detection system based on SNaPshot technology was established, and samples were genotyped by capillary electrophoresis (CE). RESULTS: A multiplex detection system containing 5 semen-specific cSNPs was successfully established. In 16 semen samples, except the cSNP located in the TGM4 gene showed allele loss in cDNA detection results, the gDNA and cDNA typing results of other cSNPs were highly consistent. When detecting semen-venous blood mixtures, the results of cSNP typing detected were consistent with the genotype of semen donor and were not interfered by the genotype of venous blood donor. CONCLUSIONS The method of semen-specific cSNPs detection by SNaPshot technology method can be applied to the genotyping of semen (stains) and provide information for determining the origin of semen in mixed body fluids (stains).
Genetic Markers ; Semen ; Polymorphism, Single Nucleotide ; DNA, Complementary/genetics* ; Body Fluids ; RNA, Messenger/genetics* ; DNA ; Saliva ; Forensic Genetics/methods*

OBJECTIVE: To investigate the effect of acid stimulation on salivary flow rate and compositions of human parotid and submandibular glands, so as to provide basis for comprehensive evaluation of salivary gland function in both health and disease status. METHODS: In the study, 210 healthy participants' whole saliva samples were collected under passive drooling, and their parotid gland and submandibular gland secretions were collected by negative pressure suction. 2% citric acid was dropped on the tip of tongue every 1 min for acid stimulation for a total of 5 times to collect stimulated whole saliva, parotid and submandibular gland saliva. The collected saliva was weighed and saliva flow rate was calculated. The K⁺, Na⁺, Cl^-, Ca²⁺, total protein, total phosphorus and α-amylase in saliva samples were detected by biochemical analyzer, and the changing features of flow rate and compositions of different kinds of saliva were compared and analyzed. RESULTS: After acid stimulation, saliva flow rate significantly increased. The increase proportion of parotid gland saliva (10.7 folds) was much higher than that of submandibular gland saliva (2.9 folds). The concentrations of Na⁺, Cl^-, Ca²⁺, total protein and α-amylase in parotid gland saliva increased significantly (P < 0.05), but there was no significant difference in total phosphorus and K⁺ (P=0.89, P=0.34). The concentration of Na⁺ and Ca²⁺ in saliva of submandibular gland increased significantly(P < 0.05), the concentration of total phosphorus decreased significantly(P < 0.05), and the concentration of Cl^- increased, but the difference was not significant(P=0.068). There was no significant difference in total protein, K⁺ and α-amylase (P=0.85, P=0.07, P=0.95). The compound secretion rate of total phosphorus in saliva of submandibular gland remained unchanged(P=0.066), while the secretion rate of K⁺, Na⁺, Cl^-, Ca²⁺, total protein and α-amylase significantly increased(P < 0.01). The compound secretion rate of K⁺, Na⁺, Cl^-, Ca²⁺, total protein and total phosphorus and α-amylase in parotid gland saliva increased(P < 0.01). The concentrations of Na⁺, Cl^-, K⁺, total phosphorus, total protein and α-amylase in parotid were higher than those in submandibular gland (P < 0.01), and the concentration of Ca²⁺ in submandibular gland saliva was significantly higher than that in parotid (P < 0.001). CONCLUSION The response of parotid to acid stimulation is stronger, and the secretion of submandibular gland is more stable. Acid stimulation significantly influences the concentrations of electrolytes in saliva, and the composited secretion rate is an evaluation index to reflect both flow rate and composition concentration of saliva. The parotid gland plays an important role in the secretion of total protein, total phosphorus and α-amylase in saliva, and the submandibular gland is the main source of Ca²⁺ in saliva.
Humans ; Parotid Gland ; Saliva ; Secretory Rate ; Submandibular Gland ; Tongue

Adult ; Aged ; Antibodies, Viral/metabolism* ; China ; Female ; Humans ; Immunoglobulin G/metabolism* ; Male ; Measles/metabolism* ; Measles virus/physiology* ; Medical Staff ; Middle Aged ; Saliva/virology* ; Young Adult

OBJECTIVES: To establish a system for simultaneous detection of miR-888 and miR-891a by droplet digital PCR (ddPCR), and to evaluate its application value in semen identification. METHODS: The hydrolysis probes with different fluorescence modified reporter groups were designed to realize the detection of miR-888 and miR-891a by duplex ddPCR. A total of 75 samples of 5 body fluids (including peripheral blood, menstrual blood, semen, saliva and vaginal secretion) were detected. The difference analysis was conducted by Mann-Whitney U test. The semen differentiation ability of miR-888 and miR-891a was evaluated by ROC curve analysis and the optimal cut-off value was obtained. RESULTS: There was no significant difference between the dual-plex assay and the single assay in this system. The detection sensitivity was up to 0.1 ng total RNA, and the intra- and inter-batch coefficients of variation were less than 15%. The expression levels of miR-888 and miR-891a detected by duplex ddPCR in semen were both higher than those in other body fluids. ROC curve analysis showed that the AUC of miR-888 was 0.976, the optimal cut-off value was 2.250 copies/μL, and the discrimination accuracy was 97.33%; the AUC of miR-891a was 1.000, the optimal cut-off value was 1.100 copies/μL, and the discrimination accuracy was 100%. CONCLUSIONS In this study, a method for detection of miR-888 and miR-891a by duplex ddPCR was successfully established. The system has good stability and repeatability and can be used for semen identification. Both miR-888 and miR-891a have high ability to identify semen, and the discrimination accuracy of miR-891a is higher.
Female ; Humans ; Body Fluids/chemistry* ; MicroRNAs/analysis* ; Real-Time Polymerase Chain Reaction/methods* ; Saliva/chemistry* ; Semen/chemistry* ; Male