Salivary Samples Research Articles

Vitamin A Positively Correlates with Secretory Immunoglobulin A: A Cross-Sectional Study in Omicron COVID-19 Outpatients.

Background: Respiratory tract infections remain among the leading causes of mortality worldwide. The COVID-19 pandemic has highlighted the importance of mucosal immunity in defending against infectious agents. Vitamin A is known to influence the production of secretory immunoglobulin A (SIgA) predominantly in the gut, where it is a critical component of the first line of defense on mucosal surfaces. Methods: This cross-sectional study, conducted 14 days post-positive COVID-19 diagnosis, aimed to determine the relationship between the nutritional status of vitamin A and SIgA levels in COVID-19 outpatients. Serum and saliva samples were collected. Vitamin A nutritional status was determined based on the assessment of dietary intake and the analysis of retinol-binding protein 4 (RBP4). SIgA levels were analyzed from salivary samples. In addition, serum antibodies were analyzed. Results: Dietary vitamin A intake and RBP4 levels positively correlated with SIgA. Patients with higher vitamin A intake showed higher SIgA/IgG1 and SIgA/IgG3 ratios, while those with higher RBP4 levels showed higher SIgA/IgM, SIgA/IgG1, and SIgA/IgG2 ratios. Conclusions: These findings underscore a significant correlation between vitamin A nutritional status and SIgA levels in COVID-19 outpatients, which may suggest the potential importance of maintaining optimal vitamin A levels for the prevention of viral infections.

TGFβ signaling pathway in salivary gland tumors

ObjectivePleomorphic adenoma (PA), mucoepidermoid carcinoma (MEC), and adenoid cystic carcinoma (ACC) are the most prevalent salivary gland tumors. Their pathogenesis has been recently associated with complex molecular cascades, including the TGFβ signaling pathway. The aim of this study was to evaluate the expression of genes associated with the TGFβ signaling pathway (TGFB1, ITGB6, SMAD2, SMAD4, FBN1, LTBP1, and c-MYC) to map possible downstream alterations in the TGFβ cascade. DesignThirteen PA, 17 MEC, 13 ACC, and 10 non-neoplastic salivary gland samples were analyzed by real-time RT-PCR. ResultsCases of PA presented increased TGFB1, LTPB1, c-MYC, and FBN1 expressions, whereas SMAD2 expression was decreased when compared to non-neoplastic tissue. MEC patients displayed increased expressions of TGFB1, ITGB6, FBN1, and c-MYC and decreased expressions of SMAD2 and SMAD4. ACC cases exhibited elevated expressions of the investigated genes except TGFB1. The present results suggest that decreased expression of SMAD2 and SMAD4 does not impede the transcriptional regulation of c-MYC, especially in PA and MEC. Increased expressions of ITGB6, TGFB1, LTBP1, and FBN1 appear to be related to the regulation of the TGFβ signaling pathway in these tumors. Additionally, we observed a higher expression of SMAD4 in ACC and a raised expression of ITGB6 and lowered expression of SMAD2 in MEC. ConclusionsOur study demonstrated the differential expression of TGFβ cascade members in salivary gland tumors such as SMAD2/SMAD4 and c-MYC as well as the participation of ITGB6, TGFB1, LTBP1, and FBN1, contributing to the understanding of the mechanisms involved in tumor progression.

Comparison of Salivary Flow Rate, pH, Buffering Capacity, and Secretory Immunoglobulin A Levels between Children with Early Childhood Caries and Caries-free Children.

Early childhood caries (ECC) is the most common chronic disease of childhood in many developing countries, which is associated with local, systemic, psychological, and social consequences. Multiple variables are shown to be associated with an increased risk of ECC. The knowledge regarding the role of saliva in the pathophysiological process of ECC still remains controversial and unexplored. Scanty studies focused on probing the role of salivary flow rate, pH, buffering capacity, and secretory immunoglobulin A (sIgA) in unstimulated whole saliva of children with ECC and children without ECC. To assess the salivary flow rate, pH, buffering capacity, and sIgA levels in children with ECC and caries-free children and to evaluate their role in caries risk assessment.Materials and Methods: The study was carried out among 64 children aged between 24 and 71 months. Clinical examinations were carried out according to the criteria by the World Health Organization, and carious status was recorded. Subjects were categorized as group I with ECC (dmfs-Decayed, Missing or Filled Surfaces (Deciduous dentition) of ≥5), and group II included children without ECC (dmfs = 0). Unstimulated whole salivary samples were collected in a sterile vial and stored at -70°C by draining. Estimations of salivary flow rate, pH, buffering capacity, and sIgA levels were done. Digital pH meters were used for the estimation of pH and buffering capacity. A human IgA enzyme-linked immunosorbent assay (ELISA) kit was used to estimate sIgA levels. Statistical software IBM Statistical Package for the Social Sciences (SPSS) statistics 20.0 (IBM Corporation, Armonk, New York, United States of America) was used to analyze the data. The mean salivary flow rate decreased in group I children with ECC (0.15 ± 0.05) when compared to group II children without ECC (0.67 ± 0.14), which was statistically significant. In caries active children, no statistically significant correlation was found between salivary flow rate and the dmfs scores [r-value (-0.247)] and p-value (0.147). The mean level of salivary pH is decreased in group I children with ECC (4.65 ± 0.4) when compared to group II children without ECC (7.28 ± 0.18). In the caries active group, the levels of salivary pH decrease as the dmfs scores increase, and this correlation is found to be statistically significant (r-value of 0.547 and p-value of 0.002). The mean level of buffering capacity is decreased for caries-active children (5.45 ± 0.49) when compared to caries-free children (8.94 ± 0.42). In caries active children, as the dmfs scores increase, the salivary buffering capacity decreases, and this correlation is found to be not statistically significant (r-value of -0.334 and p-value of 0.161). The mean levels of sIgA in group I children with ECC were higher (10.61 ± 0.90) than that in group II children without ECC (6.11 ± 1.22). In the caries-active group, the salivary sIgA levels were comparatively higher than in the caries-free children. As the dmfs scores increase, the level of the sIgA increases in caries-active children, and this correlation is noted to be highly statistically significant (r-value of 0.769 and p-value 0.008). Children with ECC showed decreased salivary flow rate, pH, buffering capacity, and increased sIgA levels, while children without ECC showed increased salivary flow rate, pH, buffering capacity, and decreased sIgA levels. The salivary parameters, such as salivary flow rate and buffering capacity, showed no correlation with the dmfs score, while salivary pH and sIgA levels have a positive correlation in caries-active children. Sivakumar A, Narayanan R. Comparison of Salivary Flow Rate, Ph, Buffering Capacity, and Secretory Immunoglobulin A Levels between Children with Early Childhood Caries and Caries-free Children. Int J Clin Pediatr Dent 2024;17(3):334-340.

An LC-MS/MS-based method for the simultaneous quantification of melatonin, cortisol and cortisone in saliva

Disturbances in the diurnal pattern are associated with several clinical and psychological conditions, including depression and fatigue. Salivary sampling for melatonin, cortisol and cortisone provides a non-invasive method for frequent sampling and obtaining biochemical insight into the diurnal pattern of individuals. Therefore, a new liquid chromatography-tandem mass spectrometry-based method for the measurement of salivary melatonin, cortisol and cortisone was developed and validated. The method required 250 μl saliva, used isotope dilution methodology and was based on a liquid-liquid extraction for sample preparation, reversed-phase chromatography and multiple reaction monitoring on a mass spectrometer for quantitation. The lower limits of quantification obtained were 0.010 nmol/L for melatonin, 0.5 nmol/L for cortisol and 1.00 nmol/L for cortisone and the limits of detection were 0.003 nmol/L, 0.15 nmol/L and 0.1 nmol/L respectively. The method imprecision was ≤14% for all measurands, and the method comparison showed highly comparable results with high correlation coefficients (all ≥0.964). Potential interference of cortisol and cortisone by prednisolone was observed and could be detected by chromatogram review. Typical diurnal patterns for melatonin, cortisol and cortisone were observed in the saliva of 20 cancer survivors who collected saliva throughout the day.

Effect of Occupational Stress on Periodontitis According to the Salivary RANKL Level Among Iraqi Employees.

Findings show that periodontitis does not affect all populations; similarly, some individuals present risk conditions such as occupational stress, making them more susceptible to developing periodontitis through unhealthy habits like poor oral hygiene and immune suppression. Periodontitis triggers an inflammatory host immune response; "Receptor Activator Nuclear Factor KB ligand (RANKL)" is the primary regulator of osteoclast differentiation and activity. It was found that osteoclastic bone damage caused by periodontitis depends on the RANKL produced by osteoblastic and periodontal ligament cells. This study aimed to assess the effect of occupational stress on employees with periodontitis using salivary RANKL marker. A case-control analysis was done at my clinic with 90 male employees aged 30-50. The participants completed self-administered questionnaires and had periodontal exams. Employee occupational stress was estimated using a life events scale questionnaire. Calibrated dentists performed the parameters used in the periodontal assessment after collecting whole unstimulated salivary samples from each employee to measure salivary RANKL using ELISA technique. The present finding revealed a statistically significant difference among groups in "probing pocket depth, plaque index, bleeding on probing, clinical attachment level, and salivary RANKL level". They were higher in the stressed employees' group, which is not statistically significant. The findings of this investigation observed that occupational stress increased clinical periodontal parameters and salivary RANKL of periodontitis in employees.

The effect of bubble nasal continuous positive airway pressure application on saliva cortisol levels in full-term neonates

Background Neonates with respiratory distress are commonly treated with bubble nasal continuous positive airway pressure (nCPAP) and undergo many procedures that cause stress-induced pain. Salivary cortisol is a biomarker of alteration in the hypothalamic-pituitary-adrenal axis caused by repeated and long-term exposure to stress.
 Objective To analyze the effect of bubble nCPAP use on salivary cortisol levels in full-term infants.
 Methods This study used a one-group pre-test­–post-test design to compare salivary cortisol levels before and 30 minutes after bubble nCPAP application. Salivary cortisol was measured using an ELISA method. Pain was also assessed at the same time points using the Neonatal Infant Pain Scale (NIPS) score. We included infants of 37 0/7 to 42 6/7 weeks’ gestational age with respiratory distress necessitating bubble nCPAP application. Infants with birth weight of <2,500 grams, major congenital anomalies, an APGAR score of <5 at 5 minutes, shock, and infants who had undergone surgery were excluded.
 Results A total of 38 subjects participated in this study. Prior to bubble nCPAP application, median cortisol levels were significantly lower (1.65 ng/mL) than after bubble nCPAP application (6.8 ng/mL) (p value?). There were no significant differences in cortisol increase based on gender, type of birth, or salivary cortisol sampling time. There were significant differences in pain level after the 30-minute nCPAP application.
 Conclusion An increase in cortisol levels and pain scale scores during administration of bubble nCPAP indicates a pain response in full-term neonates; therefore, this procedure should be accompanied by pain or stress management.

Long-acting porcine ACTH stimulated salivary cortisol reduces the overdiagnosis of adrenal insufficiency compared to serum cortisol in cirrhosis liver.

There are no reliable methods in clinical practice to diagnose adrenal insufficiency (AI) in patients with cirrhosis owing to variable cortisol-binding protein levels. This leads to unreliable results in ACTH stimulated serum cortisol test. We aimed to estimate the long-acting porcine (LA)ACTH-stimulated serum and salivary cortisol levels of patients at different stages of cirrhosis using second generation electrochemiluminescence and to determine the prevalence of true adrenal insufficiency in these patients. We included 135 noncritical patients with cirrhosis (45 each from CHILD A, Band C) and 45 healthy controls. Serum and salivary samples were collected at baseline in the morning and at 1and 2 h after LA-ACTH injection. In healthy subjects, the 2.5th centile of 2 h ACTH stimulated serum and salivary cortisol were 19.8and 0.97 μg/dL, which were used as cut-offs for defining AI based on serum and saliva respectively. The median (interquartile-range) 2-h stimulated salivary cortisol in Child A, B, C categories and controls were 1.36(1.23-2.38), 1.46(1.18-2.22), 1.72(1.2-2.2) and 2.12(1.42-2.72) μg/dLrespectively. Six subjects (4.4%) were diagnosed to have AI based on stimulated salivary cortisol cut-off, whereas 39 (28.9%) cirrhosis subjects had inadequately stimulated serum cortisol. Three patients (symptomatic) required steroid replacement therapy. Hypoalbuminemia was identified as a major risk factor for the misdiagnosis of adrenal insufficiency by serum cortisol-based testing. Long-acting porcine ACTH stimulated salivary cortisol reduces the overdiagnosis of adrenal insufficiency compared to serum cortisol in cirrhosis liver. Stimulated salivary cortisol is a promising investigation for evaluation of adrenal function in cirrhosis and more studies are required for its further validation before clinical use.

Salivary metabolites as potential predictive biomarkers for lung surgery complications: a retrospective cross-sectional study.

Saliva is often used as a tool for identifying systemic diseases because of the noninvasive nature of its collection. Moreover, salivary metabolites can be potential predictive factors for postoperative survival. We conducted the present study to establish whether salivary metabolites can function as predictive biomarkers for lung surgery complications. Unstimulated salivary samples were collected from 412 patients before lung surgery. Salivary metabolites were analyzed comprehensively by capillary electrophoresis mass spectrometry. Clinical data with the discriminatory ability of biomarkers were assessed to predict lung surgery complications using multivariate logistic regression analysis. The primary endpoint was the risk factors for postoperative complications of Clavien-Dindo grade ≥ III. Postoperative complications of Clavien-Dindo grade ≥ III developed in 36 patients (8.7%). There was no postoperative 30-day mortality. Male sex (odds ratio [OR], 3.852; 95% confidence interval CI 1.455-10.199; p = 0.007) and salivary gamma-butyrobetaine (OR, 0.809; 95% CI 0.694-0.943; p = 0.007) were identified as significant risk factors for postoperative complications of Clavien-Dindo grade ≥ III. Salivary metabolites are potential noninvasive biomarkers for predicting postoperative complications of lung surgery.

Procalcitonin for Early Detection of Pharyngocutaneous Fistula after Total Laryngectomy: A Pilot Study.

The aim of this prospective study was to investigate the role of procalcitonin as an early diagnostic marker of pharyngocutaneous fistula (PCF) in a cohort of head and neck patients treated with total laryngectomy for squamous cell carcinoma. This prospective study was conducted on a sample of patients enrolled from January 2019 to March 2022. All patients were subjected to a "protocol" of blood chemistry investigations, scheduled as follows: complete blood count with formula, ESR dosage, CPR, and PCT. PCT was also dosed by salivary sampling and a pharyngo-cutaneous swab in patients who presented with PCF. The dosage scheme was systematically repeated: the day before the intervention (t0); the 5th day postoperative (t1); the 20th day postoperative (t2); and at time X, the day of the eventual appearance of the pharyngocutaneous fistula. A total of 36 patients met the inclusion criteria. The patients enrolled in the study were subsequently divided into two groups: 27 patients underwent total laryngectomy (TL) for laryngeal cancer without postoperative complications, and 9 patients were undergoing TL with postoperative PCF. Using the Cochran's Q test, statistical significance was found for PCT among T0, T1, Tx, and T2 (p-value < 0.001) between the PCF and non-PCF groups. The Z test demonstrated that there is a difference in PCT levels at T1 and T2 and that this difference is statistically significant (p < 0.001). PCT could be considered an early marker of complications in open laryngeal surgery. According to our results, it could be useful in the precocious detection of pharyngocutaneous fistulas and in the management of antibiotic therapy.

Unraveling the microbiome-metabolome nexus: a comprehensive study protocol for personalized management of Behçet's disease using explainable artificial intelligence.

The presented study protocol outlines a comprehensive investigation into the interplay among the human microbiota, volatilome, and disease biomarkers, with a specific focus on Behçet's disease (BD) using methods based on explainable artificial intelligence. The protocol is structured in three phases. During the initial three-month clinical study, participants will be divided into control and experimental groups. The experimental groups will receive a soluble fiber-based dietary supplement alongside standard therapy. Data collection will encompass oral and fecal microbiota, breath samples, clinical characteristics, laboratory parameters, and dietary habits. The subsequent biological data analysis will involve gas chromatography, mass spectrometry, and metagenetic analysis to examine the volatilome and microbiota composition of salivary and fecal samples. Additionally, chemical characterization of breath samples will be performed. The third phase introduces Explainable Artificial Intelligence (XAI) for the analysis of the collected data. This novel approach aims to evaluate eubiosis and dysbiosis conditions, identify markers associated with BD, dietary habits, and the supplement. Primary objectives include establishing correlations between microbiota, volatilome, phenotypic BD characteristics, and identifying patient groups with shared features. The study aims to identify taxonomic units and metabolic markers predicting clinical outcomes, assess the supplement's impact, and investigate the relationship between dietary habits and patient outcomes. This protocol contributes to understanding the microbiome's role in health and disease and pioneers an XAI-driven approach for personalized BD management. With 70 recruited BD patients, XAI algorithms will analyze multi-modal clinical data, potentially revolutionizing BD management and paving the way for improved patient outcomes.

Social support and perceived partner responsiveness have complex associations with salivary cortisol in married couples

Spousal support may help ameliorate the health consequences of stressful situations by downregulating cortisol. To examine how cortisol levels change in conjunction with spousal social support during discussions of a stressful situation, 191 married couples engaged in two 10-minute interactions addressing a personal (i.e., non-marital) problem. We coded for positive and negative social support provision and receipt, assessed the perception of received support, and collected salivary cortisol samples. We found that wives’ display of more negative behaviors while receiving support was associated with an increase in wives’ cortisol levels via an indirect (mediated) effect of perceived partner responsiveness. Overall, results suggest a link between support behaviors, changes in cortisol and perceived partner responsiveness, with more consistent links between support behaviors and responsiveness ratings relative to other paths, and cortisol effects found more often in wives than husbands. Exploratory analyses also suggest that cortisol levels coming into an interaction may impact elements of support interactions. The implications of the role of cortisol and partner responsiveness to the provision of spousal support are discussed.

Exposure to Ambient Particulate Matter during Pregnancy: Implications for Infant Telomere Length

Background: Growing evidence suggests that air pollution may influence fetal development, with potential consequences for later health. Alteration of telomere length (TL) is one possible mediating mechanism for the link between fetal exposure to air pollution and the development of disease. However, the few studies exploring associations between prenatal pollution and infant TL have assessed varied trimesters of pregnancy and shown mixed results. The aim of this study was to examine the differential relationships between prenatal exposure to air pollutant PM2.5 during the first, second, and third trimesters of pregnancy with infant TL at one month of age. Methods: Women (n = 74) were recruited in obstetric clinics during their third trimester. Data on PM2.5 exposure for each woman’s residential area during each trimester was acquired from the regional Air Quality Management District. At one month postnatal, a salivary sample was collected from the infant, which provided DNA for the telomere assay. Women completed questionnaires about stressors in their lives, perceived stress, depression, and sociodemographics for inclusion as covariates. Multiple linear regression was used to analyze the results. Results: PM2.5 exposure during the second (β = 0.31, p = 0.003) and third (β = 0.24, p = 0.02) trimesters was associated with longer infant TL. Exposure in the first trimester was not related to TL. Covariates of maternal depression and age and infant female sex were also associated with longer TL. Variables in the model contributed to 34% of the variance in TL (F = 10.58, p = 0.000). Discussion: Fetal programming of longer telomeres in response to pollution may have adaptive value in preparing the neonate for a postnatal environment that is less than optimal in terms of air quality. Alternatively, longer telomeres may forecast later health risks, considering established links between longer TL and diseases such as cancer. Future research needs to address how prenatal pollution interacts with TL to influence health over time.

The Impact of Hearing Aids on Listening Effort and Listening-Related Fatigue - Investigations in a Virtual Realistic Listening Environment.

Participation in complex listening situations such as group conversations in noisy environments sets high demands on the auditory system and on cognitive processing. Reports of hearing-impaired people indicate that strenuous listening situations occurring throughout the day lead to feelings of fatigue at the end of the day. The aim of the present study was to develop a suitable test sequence to evoke and measure listening effort (LE) and listening-related fatigue (LRF), and, to evaluate the influence of hearing aid use on both dimensions in mild to moderately hearing-impaired participants. The chosen approach aims to reconstruct a representative acoustic day (Time Compressed Acoustic Day [TCAD]) by means of an eight-part hearing-test sequence with a total duration of approximately 2½ h. For this purpose, the hearing test sequence combined four different listening tasks with five different acoustic scenarios and was presented to the 20 test subjects using virtual acoustics in an open field measurement in aided and unaided conditions. Besides subjective ratings of LE and LRF, behavioral measures (response accuracy, reaction times), and an attention test (d2-R) were performed prior to and after the TCAD. Furthermore, stress hormones were evaluated by taking salivary samples. Subjective ratings of LRF increased throughout the test sequence. This effect was observed to be higher when testing unaided. In three of the eight listening tests, the aided condition led to significantly faster reaction times/response accuracies than in the unaided condition. In the d2-R test, an interaction in processing speed between time (pre- vs. post-TCAD) and provision (unaided vs. aided) was found suggesting an influence of hearing aid provision on LRF. A comparison of the averaged subjective ratings at the beginning and end of the TCAD shows a significant increase in LRF for both conditions. At the end of the TCAD, subjective fatigue was significantly lower when wearing hearing aids. The analysis of stress hormones did not reveal significant effects.

A distinct immune cytokine profile is associated with morning cortisol and repeated stress.

The objective of this study was to investigate possible immune cytokine trends throughout a week-long surgical simulation mass-casualty training session in order to determine the effects of stress inoculation on the immune system. Thirty-seven military medical students participated in a hyper-realistic surgical simulation training event conducted at Strategic Operations site in San Diego, California. Salivary samples were collected every morning of the stress training exercise for 4 consecutive days. Cortisol, along with a panel of 42 immune cytokines, was measured using multiplex enzyme-linked immunosorbent assays from Eve Technologies. The determined concentrations were averaged and plotted on a scatter plot, and then points were fit to a second-order polynomial trendline of best fit to measure. The cytokines epidermal growth factor, growth-related oncogene-α, interleukin (IL)-1α, and platelet-derived growth factor-AA followed a noted pattern of cortisol decrease throughout the week. In addition, cytokines IL-27, granulocyte colony stimulating factor, IL-10, and IL-13 demonstrated a late peak, followed by a return to baseline at the conclusion of training. Finally, the cytokine monocyte chemoattractant protein-1 displayed a decline throughout the week followed by an increase on the last day of stress training. Altogether, these results help to identify important biomarkers that may help to improve long-term stress adaptation and prevent post-traumatic stress disorder following exposure to repeated stress.

Correlation of Circadian Rhythms and Improvement of Depressive Symptoms in Acute Ischemic Stroke Patients

To investigate the correlation between evening melatonin timing secretion, dim light melatonin onset (DLMO), and post-stroke depression (PSD) in acute ischemic stroke patients and their influence on the improvement of depressive symptoms. 120 patients with a recent magnetic resonance imaging confirmed stroke were included. Salivary melatonin samples were collected at 5 time points within 1 week after hospitalization (7 p.m.-11 p.m., 1 sample per hour). The circadian phase was defined by calculating DLMO secretion. Post-stroke depressive symptoms were evaluated by the 17-item Hamilton Rating Scale for Depression (HRSD) both on day 7 of hospitalization and 3 months after stroke. Patients were divided into PSD and non-PSD groups based on whether the acute phase HRSD score was ≥8. Similarly, patients were divided into the improved depressive symptoms (IDS) and no improvement in depressive symptoms (non-IDS) groups based on whether the HRSD score at 3 months was lower than at baseline. Neurological recovery at 3 months was assessed using the modified Rankin Scale (mRS). The difference in DLMO between PSD and non-PSD patients was not statistically significant (p =0.173). In the non-IDS group, there was a significant decrease in melatonin secretion at 10 p.m. (p =0.012), and DLMO was significantly later than in the IDS group (p =0.017). Logistic regression analysis showed that DLMO (OR 1.91, 95%CI:1.13-3.23, p = 0.016) was an independent risk factor for persistent no improvement in depressive symptoms, which was associated with a markedly worse prognosis (p <.001). Our findings suggest possible interventions for the very early identification of non-IDS patients.

Polyphasic molecular approach to the characterization of methanogens in the saliva of Tunisian adults

ObjectivesMethanogenic archaea are a minor component of human oral microbiota. Due to their relatively low abundance, the detection of these neglected microorganisms is challenging. This study concerns the presence of methanogens in salivary samples collected from Tunisian adults to evaluate their prevalence and burden using a polyphasic molecular approach. MethodsA total of 43 saliva samples were included. Metagenomic and standard 16S rRNA sequencing were performed as an initial screening to detect the presence of methanogens in the oral microbiota of Tunisian adults. Further investigations were performed using specific quantitative real-time PCR targeting Methanobrevibacter oralis and Methanobrevibacter smithii. ResultsMethanobrevibacter was detected in 5/43 (11.62 %) saliva samples after metagenomic 16S rRNA data analysis. The presence of M. oralis was confirmed in 6/43 samples by standard 16S rRNA sequencing. Using real-time PCR, methanogens were detected in 35/43 (81.39 %) samples, including 62.79 % positive for M. oralis and 76.74 % positive for M. smithii. These findings reflect the high prevalence of both methanogens, revealed by the high sensitivity of the real-time PCR approach. Interestingly, we also noted a significant statistical association between the detection of M. smithii and poor adherence to a Mediterranean diet, indicating the impact of diet on M. smithii prevalence. ConclusionOur study showed the presence of methanogens in the oral microbiota of Tunisian adults with an unprecedented relatively high prevalence. Choice of methodology is also central to picturing the real prevalence and diversity of such minor taxa in the oral microbiota.

Day-to-day variability of stress biomarkers during a music intervention in people living with dementia and their family caregivers.

Examination of the variability of stress biomarkers among people living with dementia and their family caregivers can provide evidence of stress reactions and corresponding self-regulation capacities, but no such research has been conducted to date. The aim of this study was to examine day-to-day variability patterns of salivary biomarkers in dyads of people living with dementia and their family caregivers and to investigate differences in variability patterns between music intervention and control groups. This study involved secondary analysis of data collected during a two-group, non-randomized open trial examining the effects of an 8-week music intervention on physiological stress markers. A total of 5791 salivary samples from 34 dyads were used to analyze the variability of morning and evening cortisol and of morning dehydroepiandrosterone sulfate (DHEA-S). The variability indices employed were the intra- and inter-individual standard deviation, coefficient of variation, and intra-class correlation coefficient. We found that family caregivers in the music intervention group had significantly greater coefficients of variation for all three biomarker endpoints than those in the control group. Our findings provide evidence that stress biomarkers in family caregivers with functional self-regulation capacities may be more likely to respond to music intervention. However, stress biomarkers in people living with dementia may not be responsive to music intervention, possibly due to their dysfunctional self-regulation capacities. Future stress biomarker studies involving dyads of people living with dementia and family caregivers should consider biomarker variability patterns in determining the effectiveness of behavioral interventions.

Microbial functional pathways based on metatranscriptomic profiling enable effective saliva-based health assessments for precision wellness

It is increasingly recognized that an important step towards improving overall health is to accurately measure biomarkers of health from the molecular activities prevalent in the oral cavity. We present a general methodology for computationally quantifying the activity of microbial functional pathways using metatranscriptomic data. We describe their implementation as a collection of eight oral pathway scores using a large salivary sample dataset (n = 9350), and we evaluate score associations with oropharyngeal disease phenotypes within an unseen independent cohort (n = 14,129). Through this validation, we show that the relevant oral pathway scores are significantly worse in individuals with periodontal disease, acid reflux, and nicotine addiction, compared with controls. Given these associations, we make the case to use these oral pathway scores to provide molecular health insights from simple, non-invasive saliva samples, and as molecular endpoints for actionable interventions to address the associated conditions.

Comparison of the Antibacterial Efficacy of Bamboo Shoot Ethanol Extract With Chlorhexidine Mouth Rinse Against Salivary Streptococcus mutans and Lactobacillus acidophilus: An Ex Vivo Study.

Background Dental caries is the most prevalent polymicrobial oral infectious disease tormenting individuals' healthy lifestyles and presents a significant public health problem. The objective of this study was to evaluate and compare the antibacterial properties of different concentrations of bamboo shoot ethanol extract with chlorhexidine mouth rinse on isolates of salivary Streptococcus mutans (S. mutans) and Lactobacillus acidophilus (L. acidophilus). Materials and methods Non-stimulated salivary samples from 30 young adults were treated ex vivo with bamboo shoot ethanolic extract at concentrations of 30 µg/ml, 40 µg/ml, 50 µg/ml, and 60 µg/ml. The colony-forming units were quantified by measuring the number of viable bacterial cells. Inhibition zones were evaluated using the agar diffusion method. One-way ANOVA and post-hoc test were used to analyze the significant difference between variables using SPSS version 22.0 (IBM Corp., Armonk, NY). Results The mean zone of inhibition with bamboo shoot ethanolic extract against salivary S. mutans (23.00 ± 0.816) and L. acidophilus (22.00 ± 0.816) total counts was closest to the control chlorhexidine (S. mutans =22.00 ± 0.876 and L. acidophilus =21.10 ± 0.876). A greater activity against S. mutans and L. acidophilus is seen in the zone of inhibition of the 60 µg/ml experimental concentration of bamboo shoot ethanolic extract, with a significant difference in the disc diffusion assay. Conclusion The treatment with bamboo shoot extract was equivalent effective in the mentioned bacterial species. Clinical relevance It can be assured that preventive measures like mouth rinse and dentifrices compromising bamboo shoots, a potential dental biomaterial, would be optimistic agents for caries control, including the cariostatic effect.

Influence of controlled environmental conditions in potential salivary ocular pain biomarkers for enhancing the assessment of ocular pain.

We endeavored to identify objective salivary biomarkers for pain, a subjective sensation with a biological basis, using molecules already described related to pain. The study aimed to analyze inter-individual differences and intersession variability in salivary potential ocular pain biomarkers on healthy subjects, in samples obtained under the influence of controlled environmental conditions. Thirty-four healthy subjects, 20 male, 14 female, median age 35.44 years (range 30-40) were exposed for 30 minutes under standard environmental conditions (T: 22°C, 50% relative humidity) in the Controlled Environmental Research Laboratory (CE-Lab, Vision R&D, Valladolid Spain) in two separate visits (V1, V2) at least 24 hours apart. Saliva was collected after the exposure in each of the visits, and cortisol, α-amylase (sAA), secretory IgA (sIgA), testosterone, and soluble fraction of TNFα receptor II (sTNFαRII) were analyzed by ELISA. Repeatability of inter-subject inter-session measurements was assayed by intraclass correlation coefficient (ICC). There were no significant inter-session differences in testosterone (p = 0.2497), sTNFαRII (p = 0.6451) and sIgA (p = 0.9689) salivary levels. The reproducibility for salivary cortisol, sAA, testosterone, sTNFαRII and sIgA were 0.98 ng/ml, 20.58 U/ml, 21.07 μg/ml, 24.68 pg/ml and 0.19 pg/ml, respectively. Salivary cortisol, sAA, testosterone, sTNFαRII and sIgA yielded the following ICCs: 0.506, 0.569, 0.824, 0.870 and 0.4295, respectively; all these ICCs (except that for cortisol and sIgA) were found to be improved compared to those found previously by our group in a previous study in salivary samples obtained from healthy subjects under non-controlled environmental conditions; Cortisol´s ICC didn´t improve and was in both cases at the limit of acceptability. Environmental factors such as temperature and relative humidity affect the reproducibility of measurement of some salivary molecules which have been proposed as potential pain biomarkers. The exposure of subjects to standard controlled environmental conditions before salivary sample obtention would improve the reproducibility of these molecule measures' as potential biomarkers of chronic ocular pain.