Volume Of Saliva Research Articles

Giantin mediates Golgi localization of Gal3-O-sulfotransferases and affects salivary mucin sulfation in Sjögren's disease patients.

Sjögren's disease is a chronic autoimmune disease characterized by symptoms of oral and ocular dryness and extra-glandular manifestations. Mouth dryness is not only due to reduced saliva volume but also to alterations in the quality of salivary mucins in these patients. Mucins play a leading role in mucosa hydration and protection, where sulfated and sialylated oligosaccharides retain water molecules at the epithelial surface. The correct localization of glycosyltransferases and sulfotransferases within the Golgi apparatus determines adequate O-glycosylation and sulfation of mucins, which depends on specific golgins that tether enzyme-bearing vesicles. Here, we show that a golgin called Giantin is mislocalized in salivary glands from patients with Sjögren's disease and forms protein complexes with Gal3-O-sulfotransferases (Gal3STs), which change their localization in Giantin knockout and knockdown cells. Our results suggest that Giantin could tether Gal3ST-bearing vesicles and that its altered localization could affect Gal3ST activity, explaining the decreased sulfation of MUC5B observed in salivary glands from patients with Sjögren's disease.

Proton- compared to X-irradiation leads to more acinar atrophy and greater hyposalivation accompanied by a differential cytokine response.

Proton therapy gives less dose to healthy tissue compared to conventional X-ray therapy, but systematic comparisons of normal tissue responses are lacking. The aim of this study was to investigate late tissue responses in the salivary glands following proton- or X-irradiation of the head and neck in mice. Moreover, we aimed at investigating molecular responses by monitoring the cytokine levels in serum and saliva. Female C57BL/6J mice underwent local fractionated irradiation with protons or X-rays to the maximally tolerated acute level. Saliva and serum were collected before and at different time points after irradiation to assess salivary gland function and cytokine expression. To study late responses in the major salivary glands, histological analyses were performed on tissues collected at day 105 after onset of irradiation. Saliva volume after proton and X-irradiation was significantly lower than for controls and remained reduced at all time points after irradiation. Protons caused reduced saliva production and fewer acinar cells in the submandibular glands compared to X-rays at day 105. X-rays induced a stronger inflammatory cytokine response in saliva compared to protons. This work supports previous preclinical findings and indicate that the relative biological effectiveness of protons in normal tissue might be higher than the commonly used value of 1.1.

Black Tea Jelly Candy (Camellia Sinensis) to Increase Salivary Volume in Elderly: Preliminary Research

Background: Physiological changes in the elderly include decreased saliva production that causes dry mouth, difficulty in chewing and swallowing. Chewing gum and candies with a chewy texture like jelly can help stimulate the salivary glands. Black tea contains some phenolic and flavonoid compounds that have antioxidant properties that can increase the saliva flow rate. Objective: To determine the gap in saliva volume of elderly subjects before and after chewing black tea jelly candy compared to the saliva production when subjects chewed non-black tea candies and the control group (no treatment). This study also determined the prevalence of xerostomia in subjects. Materials and Methods: This field experiment was conducted using a Randomized Controlled Clinical Trials design with a pretest-posttest control group design. 30 elderly subjects aged 45-90 years in the Tresna Werda Budi Mulia 1 Nursing home, Jakarta were selected based on the predetermined inclusion criteria. They signed the informed consent and answered the Summated Xerostomia Inventory Questionnaire (SXI). Salivary volume before and after chewing black tea jelly candy was measured using a measuring cup. Statistical tests consisting of Oneway ANOVA and Dependent T-Test were performed to analyze the data. Results: The prevalence of elderly who complaining of xerostomia in this research was 40%. There was a significant gap in saliva volume between the three groups with p = 0.002 (P<0.05). An increase in saliva volume in the black tea jelly candy treatment group was identified. The average volume before intervention in the black tea jelly candy treatment group was 1.26 mL and after the intervention was 2.15 mL. Conclusion: Chewing black tea jelly candy increase the saliva volume in elderly subjects.

An automated syringe-based PoC RT-LAMP LFB platform for infectious disease detection from saliva

Decentralized Point-of-Care (PoC) diagnostics hold momentous potential for rapid and accessible viral infection disease detection. Presented is a unique design application of an easy-to-use (plug-and-play) platform for viral detection. The platform leverages a simplified multiplex Reverse-Transcription Loop-mediated Isothermal Amplification (RT-LAMP) Lateral Flow Biosensor (LFB) assay with a lyophilized master mix, eliminating the need for RNA isolation or special reporting equipment. A user-friendly Saliva Measuring Tube (SMT) ensures accurate saliva volume self-collection, and a Syringe-based PoC (SPoC) platform automates sample treatment, reagent mixing, and temperature control using readily available components and consumables. The platform’s performance was evaluated by multiplexed detection of the SARS-CoV-2 N2 target gene and human ACTB gene from saliva samples. The SPoC platform achieved a detection limit of spiked 500 copies/mL for SARS-CoV-2 and consistent internal control readout. The presented PoC system offers a promising initial step for further development toward a decentralized solution for viral infection testing.

Transdermal pilocarpine on the skin over salivary glands to increase salivation: an in vivo study

BackgroundHyposalivation is treated using oral cholinergic drugs; however, systemic side effects occasionally lead to discontinuation of treatment. We aimed to investigate the effects of transdermal pilocarpine on the salivary gland skin on saliva secretion and safety in rats.MethodsPilocarpine was administered to rats orally (0.5 mg/kg) or topically on the salivary gland skin (5 mg/body). Saliva volume, the number of sweat dots, and fecal weight were measured along with pilocarpine concentration in plasma and submandibular gland tissues.ResultsSaliva volume significantly increased 0.5 h after oral administration and 0.5, 3, and 12 h after topical administration. Fecal weight and sweat dots increased significantly 1 h after oral administration; however, no changes were observed after topical application. The pilocarpine concentration in the submandibular gland tissues of the topical group was higher than that in the oral group at 0.5, 3, and 12 h of administration.ConclusionsPilocarpine application to salivary gland skin persistently increased salivary volume in rats without inducing sweating or diarrhea. Transdermal pilocarpine applied to the skin over the salivary glands may be an effective and safe treatment option for hyposalivation.

Evaluating diagnostic accuracy of an RT-PCR test for the detection of SARS-CoV-2 in saliva

Background and objectiveSaliva has been proposed as a potential more convenient, cost-effective, and easier sample for diagnosing SARS-CoV-2 infections, but there is limited knowledge of the impact of saliva volumes and stages of infection on its sensitivity and specificity.MethodsIn this study, we assessed the performance of SARS-CoV-2 testing in 171 saliva samples from 52 mostly mildly symptomatic patients (aged 18 to 70 years) with a positive reference standard result at screening. The samples were collected at different volumes (50, 100, 300, and 500 µl of saliva) and at different stages of the disease (at enrollment, day 7, 14, and 28 post SARS-CoV-2 diagnosis). Imperfect nasopharyngeal (NP) swab nucleic acid amplification testing was used as a reference. We used a logistic regression with generalized estimating equations to estimate sensitivity, specificity, PPV, and NPV, accounting for the correlation between repeated observations.ResultsThe sensitivity and specificity values were consistent across saliva volumes. The sensitivity of saliva samples ranged from 70.2% (95% CI, 49.3–85.0%) for 100 μl to 81.0% (95% CI, 51.9–94.4%) for 300 μl of saliva collected. The specificity values ranged between 75.8% (95% CI, 55.0–88.9%) for 50 μl and 78.8% (95% CI, 63.2–88.9%) for 100 μl saliva compared to NP swab samples. The overall percentage of positive results in NP swabs and saliva specimens remained comparable throughout the study visits. We observed no significant difference in cycle number values between saliva and NP swab specimens, irrespective of saliva volume tested.ConclusionsThe saliva collection offers a promising approach for population-based testing.

Curcumin effects on age-related changes in oral immunity: an in vivo study.

The current study aimed to investigate the effects of ageing on oral immunity using β-defensin (DEFB) 1/2 as a marker and evaluate the effects of curcumin (CUR) on these processes. The study sample included thirty male C57BL/6J mice divided into three groups based on the treatment method used. The young control (YC) and old control (OC) groups received 0·5 % methylcellulose-400 (CUR vehicle) orally for 5 days, whereas the CUR group of older mice received a CUR solution suspended in 0·5 % methylcellulose-400 (dose: 3·0 mg/kg body). DEFB1/2 and immune indicator levels were measured in the saliva and salivary glands post-treatment. The saliva volume and protein content were significantly reduced in the OC group compared with the YC group. CUR administration restored these parameters, decreased DEFB1 expression in the salivary gland and increased DEFB1/2 secretion and DEFB2 expression. These findings were supported by epigenetic gene regulation and partial cytokine activation from changes in WD40 repeat protein 5, TNF alpha and IL-1beta. CUR can partially restore age-related changes in oral immune responses and promote oral health, thereby preventing frailty in the older population through a nutritional therapeutic pathway.

Retroductal dexamethasone administration promotes the recovery from obstructive and inflammatory salivary gland dysfunction.

Salivary gland dysfunction, often resulting from salivary gland obstruction-induced inflammation, is a prevalent condition. Corticosteroid, known for its anti-inflammatory and immunomodulatory properties, is commonly prescribed in clinics. This study investigates the therapeutic implications and potential side effects of dexamethasone on obstructive sialadenitis recovery using duct ligation mice and salivary gland organoid models. Functional and pathological changes were assessed after administering dexamethasone to the duct following deligation 2 weeks after maintaining ligation of the mouse submandibular duct. Additionally, lipopolysaccharide- and tumor necrosis factor-induced salivary gland organoid inflammation models were established to investigate the effects and underlying mechanisms of action of dexamethasone. Dexamethasone administration facilitated SG function restoration, by increasing salivary gland weight and saliva volume while reducing saliva lag time. Histological evaluation revealed, reduced acinar cell atrophy and fibrosis with dexamethasone treatment. Additionally, dexamethasone suppressed pro-inflammatory cytokines IL-1β and TNF expression. In a model of inflammation in salivary gland organoids induced by inflammatory substances, dexamethasone restored acinar markers such as AQP5 gene expression levels, while inhibiting pro-inflammatory cytokines TNF and IL6, as well as chemokines CCL2, CXCL5, and CXCL12 induction. Macrophages cultured in inflammatory substance-treated media from salivary gland organoid cultures exhibited pro-inflammatory polarization. However, treatment with dexamethasone shifted them towards an anti-inflammatory phenotype by reducing M1 markers (Tnf, Il6, Il1b, and Cd86) and elevating M2 markers (Ym1, Il10, Cd163, and Klf4). However, high-dose or prolonged dexamethasone treatment induced acino-ductal metaplasia and had side effects in both in vivo and in vitro models. Our findings suggest the effectiveness of corticosteroids in treating obstructive sialadenitis-induced salivary gland dysfunction by regulating pro-inflammatory cytokines.

Impact of saliva incorporation on the rheological properties of in vitro gastric contents formulated from sour cream.

Rheological properties of gastric contents depend on the food ingested, and on the volume and composition of secretions from the host, which may vary. This study investigates the impact of saliva regular incorporation in the stomach after a meal on the rheological properties of gastric contents, considering two levels of salivary flow (low = 0.5 and high = 1.5 mL/min). In vitro chymes were obtained by mixing sour cream, simulated gastric fluid, two different volumes of oral fluid (at-rest human saliva, SSF for Simulated Salivary Fluid or water) and adjusting pH at 3. Chymes samples were characterized at 37°C for their particle size and rheological properties. Overall, particle size distribution was not different between samples: incorporating a larger volume of saliva resulted in more heterogeneity, but the surface area moment D[3,2] and volume moment D[4,3] did not differ significantly with the oral fluid type. Shear viscosity of chyme samples was higher when saliva was incorporated, in comparison with water or SSF. In addition, as shown from data extracted at = 20 s-1 the higher the fluid volume the lower the shear viscosity, which is attributed to a dilution effect. However, this dilution effect was attenuated in the case of saliva, most likely due to its composition in organic compounds (e.g., mucins) contributing to the rheological properties of this biological fluid. In these in vitro conditions, both saliva and the salivation rate had a significant but slight impact on the rheological properties of gastric contents (of the order of 1-5 mPa s at = 20 s-1).

Interventional Prospective Studies on Xerostomia in Patients Undergoing Palliative and End-of-Life Care: A Scoping Review.

Patients undergoing palliative care often develop debilitating oral conditions, including xerostomia. These conditions may significantly impact patients' quality of life. Despite the high prevalence and adverse impact of xerostomia, effective management strategies remain unclear. This scoping review was performed to elucidate effective interventions for xerostomia in patients undergoing palliative and end-of-life care. A comprehensive search strategy was employed to identify relevant studies up to August 2023. Full-text primary articles focusing on xerostomia in patients receiving palliative care were included in the review. Eleven articles were selected for analysis, and data were extracted by six reviewers. This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Among the 11 studies, interventions ranged from oral care to saliva substitutes and methods to stimulate saliva secretion. The primary method of assessing xerostomia was the performance of subjective evaluations using visual analog scale scores or numerical rating scale scores. Various interventions including oral care regimens, topical treatments, and mixed efficacy outcomes were reported. Notably, only one study directly measured the saliva volume, highlighting a reliance on subjective endpoints in most studies. Although no definitive conclusions can be drawn regarding the most effective intervention, oral care was a preferred option for managing xerostomia in patients undergoing palliative care. Additionally, adjunctive treatments such as ice cubes, saline, and moisturizers showed promise but require further investigation. Objective measures should be incorporated into future intervention trials to complement subjective assessments and provide a comprehensive evaluation of xerostomia management strategies in this patient population.

Influence of two paraffin wax chewing gums with different con-sistencies on the stimulated salivary flow rate.

This study investigated and compared the consistency and compressive strength of two commercially available paraffin wax chewing gums (Aurosan (AU) and GC Europe (GC)), as well as their impact on stimulated salivary flow rate. Instrumental texture analysis was uti-lized to assess the consistency and compressive strength of AU and GC during a 7-min chewing period. Subsequently, stimulated salivary flow rate (sSFR) was evaluated in healthy subjects using AU and GC over a 7-minute period. The compressive strengths from the pre-liminary test were compared over time with the sialometry data. Eighty-one test subjects, comprising 33 men and 48 women, participated. Over the 7-min measurement period, dif-ferences were observed in the total amount of saliva accumulated per minute. Direct com-parison of AU and GC revealed that regardless of age and gender, the amount of saliva formed after 1 min was 0.63 times less with AU than with GC (95% CI: 0.56 - 0.70; P < 0.001). The accumulated saliva volume with AU was also significantly lower than that with GC in the first 4 min (P = 0.016). However, from minute 5 onwards, the two products no longer showed statistical differences in the total amount of saliva. Comparison of the com-pressive strength of AU and GC showed that the values after 1 and 2 min were significantly higher for AU than for GC (P < 0.05); for all other time points, the compressive strength was higher for GC. In the mixed-effects model after log-transformation of compressive strength and saliva volume, GC exhibited decreasing saliva volumes with increasing compressive strength (P <0.001). Conversely, the opposite was observed for AU (P = 0.019). The study suggests that the consistency or compressive strength of paraffin wax chewing gums from different manufacturers could impact sSFR.

Salivary buffering capacity is correlated with umami but not sour taste sensitivity in healthy adult Japanese subjects

ObjectiveSaliva serves multiple important functions crucial for maintaining a healthy oral and systemic environment. Among them, the pH buffering effect, which is primarily mediated by bicarbonate ions, helps maintain oral homeostasis by neutralizing acidity from ingested foods. Therefore, higher buffering capacity, reflecting the ability to neutralize oral acidity, may influence taste sensitivity, especially for sour taste since it involves sensing H+ ions. This study aims to explore the relationship between salivary buffering capacity and taste sensitivities to the five basic tastes in healthy adult humans. DesignEighty seven healthy adult students participated in this study. Resting saliva volume was measured using the spitting method. The liquid colorimetric test was used to assess salivary buffering capacity. The whole-mouth taste testing method was employed to determine the recognition threshold for each tastant (NaCl, sucrose, citric acid, quinine-HCl, monosodium glutamate). ResultsTaste recognition thresholds for sour taste as well as sweet, salty, and bitter tastes showed no correlation with salivary buffering capacity. Interestingly, a negative relationship was observed between recognition threshold for umami taste and salivary buffering capacity. Furthermore, a positive correlation between salivary buffering capacity and resting saliva volume was observed. ConclusionsSalivary buffering capacity primarily influences sensitivity to umami taste, but not sour and other tastes.

The use of bioluminescent enzyme bioassay for the analysis of human saliva: Advantages and disadvantages.

The purpose of the work was to find optimal conditions for bioluminescent enzymatic analysis of saliva (based on the use of NADH:FMN oxidoreductase + luciferase) and then to determine the biological effect of using bioluminescence assay of saliva to study the physiological state of the body under normal and pathological conditions. The saliva of snowboarders and students were studied in the "rest-training" model. The saliva of patients diagnosed with acute pharyngitis was examined in the "sick-healthy" model. Bioluminescence assay was performed with a lyophilized and immobilized bi-enzyme system using cuvette, plate, and portable luminometers. The concentrations of secretory immunoglobulin A (sIgA) and cortisol were determined by enzyme immunoassay, and the total protein content was measured by spectrophotometric method. The activity of the bioluminescent system enzymes increased as the amount and volume of saliva in the sample was decreased. The cuvette and plate luminometers were sensitive to changes in the luminescence intensity in saliva assay. Luminescence intensity correlated with the concentrations of sIgA and cortisol. The integrated bioluminescent index for saliva was reduced in the "rest-training" model and increased in the "sick-healthy" model. Thus, the non-invasive bioluminescent saliva analysis may be a promising tool for assessing the health of the population.

Comparison of Child and Adult Mastication of a Sticky Processed Cream Cheese and Simulation with a Masticator.

An advantage of masticators is the calibration and possible standardization of intra- and inter-individual mastication variability. However, mastication of soft, sticky and melting products, such as processed cream cheeses, is challenging to reproduce with a masticator. The objectives of this work were, for the cheese studied: (1) to compare child and adult mastication and (2) to find in vitro parameters which best reproduce their in vivo chewing. Five parameters influencing mastication (mouth volume, quantity consumed, saliva volume, mastication time and number of tongue-palate compressions) were measured in 30 children (5-12 years old) and 30 adults (18-65 years old) and compared between the two populations. They were then transposed to a masticator (Oniris device patent). The initial cheese, a homogeneous white paste, was surface-colored to investigate its in-mouth destructuring. In vivo boli were collected at three chewing stages (33, 66 and 99% of mastication time) and in vitro boli were obtained by varying the number of tongue-palate compressions and the rotation speed. In vivo and in vitro boli were compared by both image and texture analysis. Child masticatory parameters were proportionally smaller than those of adults. The in vivo child boli were less homogeneous and harder than adult ones. Comparison of in vivo and in vitro bolus color and texture enabled the successful determination of two in vitro settings that closely represented the mastication of the two populations studied.

A Study of Dry Mouth and Gastrointestinal Disorders in Patients Taking Antidepressant

IntroductionDry mouth is a subjective symptom of the feeling of dehydration inside of the mouth and is closely linked to reduced salivary secretion. The occurrence of dry mouth and GI disorders due to antidepressants greatly affects the course of the mental disorder and medication compliance, but it has barely ever been studied.ObjectivesThe purpose of this study was to identify the characteristics of dry mouth and gastrointestinal (GI) disorders in antidepressant patients.MethodsThe study included 103 antidepressant-taking patients. Antidepressants were classified according to their mode of action. The GI disorders were investigated using the medical records of the patients. The Patient Health Questionnaire-15 and a questionnaire for assessing dry mouth symptoms were used in this study. The questionnaire for the evaluation of dry mouth symptoms, a visual analog scale (VAS)–based instrument, developed and evaluated for reliability by Lee et al. was used to assess dry mouth. In the questionnaire, 6 VAS items were assessed for the extent of dry mouth (0-100 points) : 1) dry mouth at night or when waking up in the morning, 2) dry mouth during the day, 3) dry mouth when eating, 4) difficulty in swallowing, 5) subjective evaluation of the volume of saliva in the mouth, and 6) overall discomfort in daily life. Additionally, four items examined behaviors due to dry mouth (1-5points) : 1) frequency of waking up from sleep due to dry mouth, 2) frequency of preparing drinking water before going to bed, 3) frequency of drinking water when eating solid foods, and 4) frequency of eating hard candies or chewing gums to help dry mouth.ResultsThe score for “overall discomfort due to dry mouth in daily life” (31.72±33.82), “dry mouth at night or in the morning” (47.86±35.87), and “dry mouth during the day” (39.83±31.67) were slightly higher than “discomfort in chewing or swallowing foods”. According to somatization severity, the mean values were 116.36±113.34 in the mild, 213.18±136.98 in the moderate, and 277.59±201.44 in the severe, the between-group difference was significant (F=10.294, p&lt;0.001). According to the class of antidepressants, the mean score was 180.00±147.5 for vortioxetine, 194.25±169.33 for selective serotonin reuptake inhibitors (SSRIs), 223.61±156.70 for serotonin and norepinephrine reuptake inhibitors (SNRIs), 75.00±57.00 for norepinephrine dopamine reuptake inhibitors (NDRIs), 201.67±174.66 for Nassau, and 116.67±132.03 for agomelatine. A total of 67 (65.0%) patients had at least one GI disorder.ConclusionsThe study findings are expected to help increase medication compliance in antidepressant patients by better controlling the side effects experienced by the patients.Disclosure of InterestNone Declared

Improvement effect of gemigliptin on salivary gland dysfunction in exogenous methylglyoxal-injected rats

The symptom of hyposalivation associated with hypofunction of the salivary glands is a common feature of diabetes. Inadequate saliva production can cause tissue damage in the mouth, making it susceptible to infections and leading to oral health diseases. Previous studies have highlighted the harmful effects of methylglyoxal (MGO) and MGO-derived advanced glycation end products (AGEs) in diabetes. In this study, we investigated the protective effects of gemigliptin, a dipeptidyl peptidase-4 (DPP-4) inhibitor, against MGO-induced salivary gland dysfunction. MGO treatment of immortalized human salivary gland acinar cells induced apoptosis via reactive oxygen species (ROS)-mediated pathways, but this effect was mitigated by gemigliptin. In vivo experiments involved the simultaneous administration of MGO (17.25 mg/kg) with aminoguanidine (100 mg/kg) and gemigliptin (10 and 100 mg/kg) daily to rats for two weeks. Gemigliptin increased the saliva volume and amylase levels in MGO-injected rats. Gemigliptin reduced the DPP-4 activity in both the salivary glands and serum of MGO-injected rats. Furthermore, gemigliptin exerted anti-glycation effects by reducing the accumulation of AGEs in the saliva, salivary glands, and serum and suppressing the expression of the receptor for AGEs. These actions protected the salivary gland cells from ROS-mediated apoptosis. Overall, gemigliptin protected the salivary gland cells from ROS-mediated cell death, reduced the accumulation of amylase and mucins in the salivary glands, and enhanced the salivary function by upregulating aquaporin 5 expression, and it exerted protective effects against MGO-induced salivary gland dysfunction by enhancing the anti-glycation, antioxidant, and salivary secretion activities. Our findings suggest gemigliptin as a potential therapeutic for patients with salivary gland dysfunction caused by the complications of diabetes.

Common Drugs Causing Xerostomia

Saliva is need for maintaining a healthy mouth environment and general health.Many factors can affect the volume and compositions of saliva. Xerostoma which refers to a subjective sensation of dry mouth, is derived from the Greek words "xeros" (ξηρός), which means "dry," and "stoma" (στόμα), which means "mouth." Reduced salivary flow and altered salivary gland composition and function are the outcomes of xerostomia.Symptoms of xerstomia include dryness or a feeling of stickiness in your mouth. Saliva that seems thick and stringy, bad breath and having hard time chewing, speaking and swallowing. There are many different causes of xerostomia, which include medicine, aging, cancer therapy, nerve damage and tabaco and alcohol use. The most common drugs causing xerstomia anticholinergic drugs, antidepressant drugs, diuretics, calcium channel blocker and beta-blockers. Different mechanism of causing xerostomia cytotoxic drugs by direct damage to salivary gland, antidepressant drugs by their anticholinergic side effects, and diuretic by excreting more fluid and electrolytes.

Oral Function and the Oral Microbiome in the Elderly in the Kyotango Area.

Prevention of tooth loss contributes to an extended life expectancy, namely longevity. Aging-related oral hypofunction, including tooth loss, markedly increases the risks of functional disorder and mortality. Dysbiosis of the oral microbiome has recently been associated with various diseases, such as liver cirrhosis, pancreatic cancer, colorectal cancer, and inflammatory bowel disease. Therefore, the relationship between the oral microbiome and systemic health has been attracting increasing attention. In the present study, we examined oral function and the oral microbiome in the elderly in a world-leading longevity area. An oral examination, chewing ability/tongue-lip motor function/saliva tests, and a metagenomic analysis with a 16S rRNA gene-targeting next-generation sequencer were conducted on 78 subjects aged ≥80 years. Twenty-six healthy individuals aged between 20 and 39 years were also investigated as controls. The data obtained were statistically analyzed. The protocol of the present study was approved by the Ethics Review Board of our university (ERB-C-885). Chewing ability, tongue-lip motor function, and saliva volume were normal in elderly subjects with a current tooth number ≥20, but were significantly lower in those with a current tooth number <20. The oral microbiome in elderly subjects with a current tooth number ≥20 and young controls differed from that in elderly subjects with a current tooth number <20. Tooth number ≥20 in elderly subjects in the longevity area contributed to the maintenance of both oral function and the diversity of the oral microbiome.

Lab-on-a-lollipop (LoL) platform for preventing food-induced toxicity: all-in-one system for saliva sampling and electrochemical detection of vanillin.

Saliva has emerged as a primary biofluid for non-invasive disease diagnostics. Saliva collection involves using kits where individuals stimulate saliva production via a chewing device like a straw, then deposit the saliva into a designated collection tube. This process may pose discomfort to patients due to the necessity of producing large volumes of saliva and transferring it to the collection vessel. This work has developed a saliva collection and analysis device where the patient operates it like a lollipop, stimulating saliva production. The lollipop-mimic device contains yarn-based microfluidic channels that sample saliva and transfer it to the sensing zone embedded in the stem of the device. We have embedded electrochemical sensors in the lollipop platform to measure vanillin levels in saliva. Vanillin is the most common food flavoring additive and is added to most desserts such as ice cream, cakes, and cookies. Overconsumption of vanillin can cause side effects such as muscle weakness, and damage to the liver, kidneys, stomach, and lungs. We detected vanillin using direct oxidation at a laser-induced graphene (LIG) electrode. We showed a dynamic range of 2.5 μM to 30 μM, covering the physiologically relevant concentration of vanillin in saliva. The lab-on-a-lollipop platform requires only 200 μL of saliva and less than 2 minutes to fill the channels and complete the measurement. This work introduces the first sensor-embedded lollipop-mimic saliva collection and measurement system.

Improving CPAP Therapy with Superimposed Pressure Oscillation

Background: Continuous positive airway pressure (CPAP) is considered the gold standard therapy for Obstructive Sleep Apnea (OSA); however, many side effects, such as uncomfortable high titration pressure (TP) and mouth dryness, are associated with this treatment. This work proposes using pressure oscillations superimposed on a mean pressure to modulate the upper airways, reduce TP, and stimulate the salivary glands to reduce mouth dryness. Methods: Two nonconsecutive overnight randomized controlled clinical trials were designed, one with a standard CPAP setup but reduced TP and the other by adding superimposed pressure oscillations (SIPO) to the reduced TP CPAP setup. 33 OSA patients who usually received CPAP treatment with predetermined TP settings participated in the two trials. Complete polysomnography was performed for sleep and patient assessments. However, a spitting technique protocol was used on 15 randomly selected patients from the same group to investigate the effect of SIPO on mouth dryness. These trials are registered under ACTRN12622001518752. Results: The apnea-hypopnea index (AHI) was significantly reduced from 25.08 ± 2.32 to 17.56 ± 2.11 (p = 0.020*) with SIPO, indicating a 29.95% reduction in AHI and a decrease in breathing obstructions during enhanced therapy. Additionally, SIPO significantly decreased the oxygen desaturation index (ODI) (p = 0.002), maintaining the blood oxygen level within the normal range during the trials. ODI≥3 decreased significantly by 38.04% with SIPO. Saliva test results demonstrated that SIPO significantly increased saliva volume by 23.13% in non-stimulation and by 39.09% during stimulation compared to the CPAP trial. Conclusions: This work demonstrates that SIPO reduces the TP to 70% of its standard clinical setting and stimulates salivary secretion to reduce mouth dryness. Further, significant improvements in AHI, respiratory arousal index (RAI), Arousal index (AI), and sleep efficiency (SE) are observed. This work is proof of concept, and further trials should be undertaken to generalize the proposed technique.