Search Results (85)

The interaction between human salivary alpha-amylase (HSAmy) and amylase-binding oral streptococci (ABS) helps determine the bacteria that colonize the oral cavity by establishing dental biofilms. Streptococci are important pioneer species of the oral cavity and influence oral health as well as common diseases such as dental caries. Various oral streptococcal species express distinct amylase-binding proteins, among which amylase-binding protein A (AbpA), encoded by the abpA gene in Streptococcus gordonii and several other species, which is the most extensively studied. Amylase binding facilitates microbial adhesion to host surfaces and biofilm formation and enables bacteria to harness the host’s amylase enzymatic activity at their cell surface, enhancing their capacity to metabolize dietary starch for nutritional gain. Additionally, amylase binding may also influence bacterial cell division and stress tolerance by engaging novel bacterial signaling pathways. From an evolutionary perspective, both Neanderthals and modern humans exhibit functional adaptations in nutrient metabolism, including selection for salivary amylase-binding oral streptococci, highlighting the importance of microbial co-adaptation in response to host diet. Further research is warranted to elucidate the broader roles of amylase binding to bacteria in host-bacterial signaling, bacterial cell division and fitness and the evolutionary trajectory of the oral microbiome. Full article

Background: Dental phobia significantly impairs treatment adherence and oral health–related quality of life. While intravenous sedation (IVS) is commonly used to manage anxiety, interest in non-pharmacological alternatives is increasing. Visual color stimuli are known to affect emotional processing and autonomic nervous system activity. This study investigated whether brief exposure to colored goggles (translucent, green, blue, red) influenced physiological and psychological stress markers in patients with dental phobia undergoing IVS. Methods: Twenty patients with dental phobia (CMDAS ≥ 20) participated in a within-subject repeated measures design, experiencing all four color conditions in randomized order via Latin square. Salivary alpha-amylase (sAA), heart rate (HR), and Visual Analog Scale (VAS) scores for pain and satisfaction were measured at four time points. The Friedman test, followed by Wilcoxon signed-rank tests with Bonferroni correction, was used to compare conditions. Results: Prior to peripheral intravenous cannulation (PIC), green goggle exposure significantly reduced median sAA levels compared to the translucent control (p = 0.009). HR was lower in the green and blue conditions than in the red, although not significantly. VAS pain scores were significantly reduced under green and blue conditions; satisfaction scores remained uniformly high across all conditions. Red did not worsen stress responses compared to the control and may promote increased engagement. Conclusions: Cool color stimuli—particularly green and blue—may attenuate acute stress responses in patients with dental phobia prior to PIC. Incorporating such visual cues into preoperative environments may serve as a simple, non-invasive adjunct to managing dental anxiety. Full article

Background/Objectives: Dental fear and anxiety are areas of concern in clinical pediatric dentistry, often leading to treatment avoidance and negative oral-health consequences. Cortisol and alpha amylase, measurable in saliva, have been proposed as biomarkers of stress and may provide an objective means of assessing and monitoring distress over time. This study examined measures of psychological and physiological distress in pediatric patients undergoing dental procedures and their correlation. Methods: 7-to-17-year-old new patients scheduled for a dental procedure or orthodontic bonding completed a psychological battery assessing dental fear (using Children’s Fear Survey Schedule—Dental Subscale), stress (Perceived Stress Scale), and dental anxiety (Modified Children Dental Anxiety Scale). Before the dental appointment, we assessed anticipated pain intensity, heart rate (HR), and collected two saliva samples to quantify cortisol and alpha amylase. Correlations between psychological and physiological measures were assessed with Pearson’s correlation and treatment groups were compared with independent t-tests. Results: Out 34 participants (12.8 ± 2.7 y/o, 52.9% females, 73.5% pediatric patients and 26.5% orthodontic patients), 38.2% endorsed moderate anxiety; 85.3% reported moderate to high stress; and 29.6% indicated dental fear. Psychological distress was not influenced by procedure type. Dental fear positively correlated with dental anxiety (p < 0.001) and HR (p < 0.001); dental anxiety positively correlated with anticipated pain (p = 0.010) and HR (p = 0.003); stress positively correlated with HR (p = 0.006). Even if 72.2% of participants had cortisol value outside normal range and those with greater stress exhibited elevated cortisol, cortisol and alpha amylase levels (measured on n = 18) were not correlated with psychological variables. Conclusions: Cortisol and alpha amylase levels were not correlated with psychological measures in a cross-sectional study on pediatric patients undergoing dental procedures. Full article

Background/Objectives: The aim was to identify patterns of autonomic and neuroendocrine reactivity to an immersive virtual reality (VR) social-emotional stressor and explore their associations with perceived stress and eating behavior. Methods: This one-group pretest–posttest study included 30 children and adolescents with obesity (15 boys and 15 girls), aged 8 to 17 years. The VR protocol consisted of two consecutive phases: a 5 min relaxation phase using the Forest application and a 5 min stimulation phase using a cognitively engaging VR game designed to elicit social-emotional stress. Physiological responses were measured using heart rate variability (HRV) indices and salivary stress biomarkers, including cortisol and alpha amylase. Subjective stress and eating responses were assessed via visual analogue scales (VAS) administered immediately post-exposure. The Three-Factor Eating Questionnaire (TFEQ-R21C) was used to evaluate cognitive restraint (CR), uncontrolled eating (UE), and emotional eating (EE). Results: The cortisol reactivity was blunted and may reflect both the attenuated HPA axis responsiveness characteristic of pediatric obesity and the moderate psychological challenge of the VR stressor used in this study. Two distinct autonomic response patterns were identified via exploratory factor analysis: (1) parasympathetic reactivity, associated with increased RMSSD and SDNN and decreased LF/HF, and (2) sympathetic activation, associated with increased heart rate and alpha-amylase levels and reduced RR intervals. Parasympathetic reactivity was correlated with lower perceived stress and anxiety, but also paradoxically with higher uncontrolled eating (UE). In contrast, sympathetic activation was associated with greater cognitive restraint (CR) and higher anxiety ratings. Conclusions: This study demonstrates that immersive VR game exposure elicits measurable autonomic and subjective stress responses in children and adolescents with obesity, and that individual differences in physiological reactivity are relevantly associated with eating behavior traits. The findings suggest that parasympathetic and sympathetic profiles may represent distinct behavioral patterns with implications for targeted intervention. Full article

Salivary alpha-amylase (sAA) increases in response to stressful stimuli in a number of animal species, and it is considered a biomarker of sympathetic nervous system activation. However, no studies have been performed in which sAA has been measured in cats. The aim of this study was to perform an analytical and clinical validation of a commercially available automated assay for the determination of sAA in feline saliva. For the analytical validation, the precision, accuracy, and lower limit of quantification (LLOQ) were determined. To evaluate its response to acute stress, sAA was evaluated in feline saliva before and after stressful stimuli, consisting of a blood extraction. In addition, the sAA activity was compared between cats suffering from urinary tract pathologies and healthy controls. Analytical validation studies confirmed the method as being precise, accurate, and sufficiently sensitive for the sAA determination in cats. When the response to stress was evaluated, a statistically significant increase was detected in sAA in comparison with its activity before the blood extraction. In addition, cats with urinary tract diseases presented higher sAA activity than controls. The results of the present study indicate that sAA can be measured in feline saliva. This study could contribute to a wider use of the measurements of sAA in the saliva of cats and serve as a basis for future investigations aiming to assess acute stress in this species in a non-invasive manner. Full article

Anxiety and depression are highly prevalent mental health disorders often associated with dysregulation of neuroendocrine and immune systems, particularly the hypothalamic–pituitary–adrenal (HPA) axis and the sympathetic–adrenal–medullary (SAM) system. Recent research highlights the potential of salivary biomarkers to serve as non-invasive indicators for psychological distress. This narrative review synthesizes current evidence on key salivary biomarkers, cortisol, alpha-amylase (sAA), secretory immunoglobulin A (sIgA), chromogranin A (CgA), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), C-reactive protein (CRP), brain-derived neurotrophic factor (BDNF), and salivary microRNAs (miRNAs), in relation to anxiety, depression, and stress. A comprehensive literature search (2010–2025) was conducted using multiple databases and relevant MeSH terms. The review reveals consistent associations between these salivary analytes and stress-related disorders, reflecting changes in neuroendocrine activity, immune response, and neuroplasticity. Cortisol and sAA mirror acute stress reactivity, while cytokines and CRP indicate chronic inflammation. BDNF and miRNAs provide insight into neuroplastic dysfunction and gene regulation. Despite promising results, limitations such as variability in sampling methods and biomarker specificity remain. In conclusion, salivary biomarkers offer a promising avenue for early detection, monitoring, and personalization of treatment in mood and anxiety disorders. Conclusions: Cortisol and alpha-amylase serve as the principal markers of acute stress response, whereas cytokines such as IL-6 and TNF-α, together with CRP, indicate chronic inflammation associated with extended emotional distress. Full article

Background/Objectives: The relationship between upper trapezius muscle stiffness and choroidal circulatory dynamics remains unclear. This study aimed to examine changes in upper trapezius muscle stiffness and choroidal circulatory dynamics before and after trapezius muscle self-stretching. Methods: Eighteen healthy adults in their 20s (median age ± standard error: 21.0 ± 4.9 years) and eight healthy adults in their 40s (age: 43.0 ± 15.2 years) were included. Intraocular pressure (IOP); systolic, diastolic, and mean blood pressure (BP); heart rate (HR); ocular perfusion pressure (OPP); and salivary alpha-amylase (sAA) activity—as an indicator of autonomic nervous system function—were measured at baseline and after trapezius muscle self-stretching. Upper trapezius muscle stiffness was assessed using ultrasound strain elastography, whereas choroidal circulation was evaluated using laser speckle flowgraphy to determine the mean blur rate (MBR), a relative measure of macular blood flow velocity. Results: Significant reductions in systolic and mean BP; OPP; sAA activity; and MBR were observed after trapezius muscle self-stretching in both groups; however, no significant changes were found in IOP and HR. A significant decrease in upper trapezius muscle stiffness was observed after self-stretching only in the 20-year-old group. Conclusions: In healthy adults in their 20s and 40s, trapezius muscle self-stretching may enhance parasympathetic nervous system activity, resulting in decreased systemic and choroidal circulatory parameters. However, the reduction in muscle stiffness observed only in younger participants suggests that short-term self-stretching may be less effective in reducing trapezius muscle stiffness with advancing age. Full article

Saliva was used as non-invasive alternative to blood for diagnosing pathophysiological conditions. This study aimed to assess changes in protein profile in people with obesity after bariatric surgery and to assess the impact of exercise on these changes. The saliva proteome was determined from two-dimensional gels of twenty adults (ten people with normal weight and ten people with obesity). The effects of bariatric surgery and exercise were assessed. A decrease in body weight, body mass index, and waist-to-height ratio was observed after bariatric surgery. Low levels of carbonic anhydrase VI (CA-VI), short palate, lung, and nasal epithelium clone 2 (SPLUNC2), and haptoglobin were observed. One month after bariatric surgery, spots of haptoglobin and SPLUNC2 increased, although one CA-VI spot decreased. Zn-alpha-2 glycoprotein, immunoglobulin chains, and actin-related protein-3, which are high in people with obesity, decreased 1 month after bariatric surgery. Five months after bariatric surgery, the most significant change was the amylase decrease. The exercise-induced changes in salivary proteins increased SPLUNC, CA-VI, type S cystatins, actin cytoplasmic 1, and zinc alpha-2 glycoprotein levels and decrease Ig kappa chain C region and Rab GDP dissociation inhibitor beta. It can be concluded that the salivary proteins change between people with normal weight vs. patients with obesity, as well as after bariatric surgery and exercise programmes. Salivary proteins may be useful biomarkers in non-invasive samples for monitoring and assessing the impact of interventions on people with obesity. Full article

The sympathetic nervous system (SNS) is crucial for stress response regulation and immune modulation. Prolonged SNS activation, often induced by stress exposure, disrupts immune homeostasis and intensifies inflammatory processes, contributing to periodontal disease progression. This study investigates the relationship between SNS activity and periodontitis severity, utilizing salivary biomarkers chromogranin A (CgA) and alpha-amylase (sAA) alongside pro-inflammatory cytokines interleukin-1β (IL-1β) and interleukin-6 (IL-6). Saliva samples from 67 patients, categorized by periodontitis severity (Stages I/II and III/IV), were analyzed using enzyme-linked immunosorbent assay (ELISA). The results revealed significantly higher median levels of CgA (9.45 vs. 3.93 pmol/mL) and IL-1β (257.81 vs. 220.11 pg/mL) in patients with Stage III/IV periodontitis compared with those with Stage I/II, indicating heightened SNS activity and inflammatory response. Correlations between these biomarkers and clinical periodontal parameters, such as probing depth and clinical attachment loss, further support these findings. Despite elevated sAA levels in severe cases, statistical significance was not achieved. IL-6 levels also showed no significant variation across disease stages, although trends aligned with increased severity. This study highlights the interplay between SNA activation and periodontal inflammation, as evidenced by elevated salivary levels of CgA and IL-1β in patients with advanced periodontitis. By integrating neuroendocrine and inflammatory biomarkers into the diagnostic process, clinicians may be able to better identify patients at increased risk for periodontal breakdown and to consider adjunctive interventions such as stress management, thereby supporting more personalized approaches to periodontitis treatment. Full article

Shift work is prevalent among healthcare professionals and associated with significant health risks, including stress, sleep disturbances, and mood disorders. Despite known sex differences in stress responses, their impact on shift workers, particularly student pharmacists, is understudied. The objective of this study was to explore sex-specific differences in psychological and physiological stress responses among pharmacy students engaged in shift work. Psychological stress was assessed using validated scales like the Perceived Stress Scale (PSS), Shift Work Disorder Index (SWDI), Ford Insomnia Response to Stress Test (FIRST), and Positive and Negative Affect Schedule (PANAS). Additionally physiological stress was assessed using salivary biomarkers like cortisol, DHEA-S, IL-6, and alpha-amylase. Females reported significantly higher perceived stress (p = 0.0004), SWDI (p = 0.0302), insomnia (p = 0.0111), and negative affect (p = 0.0171) compared to males. Rotating shift workers showed elevated scores across all measures (p = 0.0005–0.0381). Female rotating shift workers exhibited higher alpha-amylases (p = 0.0191) and lower DHEA-S levels (p = 0.0176) than males. Strong correlations emerged between perceived stress and insomnia (r = 0.40, p = 0.0001) and between insomnia and negative affect (r = 0.55, p < 0.0001). Findings highlight females’ vulnerability, underscoring the need for sex-specific interventions and the early identification of stress biomarkers. Full article

Dental fear and anxiety are frequently identified as major contributing factors to non-compliance, uncooperativeness, and difficulties during dental procedures in pediatric patients. These issues can lead to avoidance of dental treatment, resulting in long-term negative consequences for oral health and overall well-being. The assessment and quantification of psychological functioning (i.e., dental fear, anxiety, and self-perceived stress) has traditionally relied on self-reported questionnaires validated for the pediatric population. While this approach is cost-effective and non-invasive, it relies on subjective self-reported data, oftentimes influenced by parental or guardian interaction, especially in young children. Salivary diagnostics has recently emerged as an objective method for the procurement of biological molecules that serve as biomarkers for a variety of oral and systemic conditions. This literature review aims to comprehensively summarize the available literature on the correlation between psychological and salivary physiological measurements assessing dental fear, dental anxiety, and self-perceived stress in pediatric dental patients, highlighting the advantages and disadvantages of each method of assessment. Four databases (PubMed^®, PsycInfo, Dentistry & Oral Sciences Source, and Web of Science) were searched for published articles, in the English language, assessing the correlation between psychological and physiological distress in children undergoing dental procedures. Studies on pediatric patients reveal positive correlations between salivary cortisol and dental fear, stress, and anxiety, especially in returning patients. Conversely, findings on salivary alpha-amylase and secretory immunoglobulin A were inconsistent, with some studies suggesting correlations with dental fear and prior dental experiences. Full article

Background/Objectives: BuZhong Yiqi Formula (BZYQF) has significant ameliorative effects on type 2 diabetes mellitus (T2DM). However, its efficacy in alleviating the hyposalivation caused by T2DM needs to be confirmed, and its mechanism is unclear. Methods: Network pharmacology and molecular docking were combined to analyze the molecular mechanism by which BZYQF alleviates T2DM-caused hyposalivation. A T2DM rat model was induced to evaluate the efficacy of BZYQF. The total saliva before and after acid stimulation was collected to determine the salivary flow rate and salivary alpha-amylase (sAA) activity. The parotid (PG) and submandibular glands (SMG) of experimental rats were removed to perform histopathology observation, biochemical indicator determination, and expression detection of signaling molecules in the salivary secretion pathway. Results: The present study screened out 1014 potential targets of BZYQF regarding the treatment of T2DM. These targets were mainly involved in the formation of the receptor complex, exercising the neurotransmitter receptor activity and regulating secretion. They were significantly enriched in the salivary secretion pathway of β1-AR/PKA/AMY1 and CHRM3/IP3R/AQP5. Furthermore, in BZYQF, nine validated compounds were able to dock into the active site of β1-AR, and three validated compounds were able to dock into the active site of CHRM3. Animal experiments confirmed that BZYQF significantly reduces fasting blood glucose, total cholesterol and triglyceride levels; enhances insulin level and HOMA-IS (p < 0.05); and increases salivary flow rate (Basal: increase from 21.04 ± 14.31 to 42.65 ± 8.84 μL/min, effect size of Cohen’s d = 6.80, p = 0.0078; Stimulated: increase from 36.88 ± 17.48 to 72.63 ± 17.67 μL/min, effect size of Cohen’s d = 7.61, p = 0.0025) and sAA activity (Basal: increase from 0.68 ± 0.32 to 2.17 ± 0.77 U/mL, effect size of Cohen’s d = 9.49, p = 0.0027; Stimulated: increase from 1.15 ± 0.77 to 4.80 ± 1.26 U/mL, effect size of Cohen’s d = 13.10, p = 0.0001) in basal and stimulated saliva in T2DM rats. Further mechanistic studies revealed that BZYQF reduces glucose and lipid accumulation, enhances acetylcholine content, improves pathological lesions and inflammation, and significantly increases the expression of salivary secretion pathway signaling molecules, including PKA, IP3R, β1-AR, AQP5, CHRM3, and AMY1 in the PG and SMG of T2DM rats (p < 0.05). Conclusions: The present study demonstrated that BZYQF is able to alleviate T2DM-caused hyposalivation by improving glucose metabolism and activating the salivary secretion pathway in the PG and SMG of T2DM rats. This study might provide a novel rationale and treatment strategy for BZYQF in diabetes-induced hyposalivation in a clinical setting. Full article

The copy number (CN) variant AMY1 encodes the salivary amylase enzyme which promotes starch digestion. Although this gene has been associated with dental caries and periodontal disease susceptibility, the impact of the interaction between AMY1 CN and starch on oral biofilms is unclear. We explored how oral microbiota communities shaped by AMY1 CN respond to starch by employing an in vitro model of biofilm formation. We cultured biofilms using saliva samples from 31 donors with a range of AMY1 CNs (between 2 and 20 copies) and self-reported gum disease states; we used media with and without starch. Many of the most prevalent genera in saliva were also prevalent in the derived biofilms. The presence of starch in the media was associated with lower biofilm alpha diversity. We found a significant interaction between AMY1 CN and the media carbohydrate content that influenced the proportions of Atopobium and Veillonella. Members of these genera have been associated with dental caries and periodontitis. These findings suggest that the effects of carbohydrates on oral microbiome composition depend on AMY1 CN and that human oral bacteria evolved in response to expansion of this host gene locus. Full article

Background/Objectives: Saliva is gaining importance as a diagnostic sample in pigs. The aim of this research was to evaluate a panel of salivary analytes in three porcine diseases and establish predictive models to detect them. Methods: Saliva samples were obtained from healthy pigs (n = 97) and pigs affected by meningitis due to Streptococcus suis (n = 118), diarrhea due to enterotoxigenic Escherichia coli (ETEC, n = 77), and porcine reproductive and respiratory syndrome (PRRS, n = 52). The following biomarkers were analyzed: adenosine deaminase (ADA), haptoglobin (Hp), calprotectin (Calp), aldolase, alpha-amylase (sAA), lactate dehydrogenase (LDH), total protein (TP), and advanced oxidation protein products (AOPPs). Predictive models based on binary logistic regression and decision trees combining those analytes for detecting specific diseases were constructed. Results: The results showed a different biomarker profile between the groups. S. suis and ETEC pigs showed higher values of ADA, Hp, Calp, aldolase, sAA, LDH, and TP than healthy pigs. Pigs with PRRS showed higher values of Hp, Calp, sAA, and LDH than healthy animals. The constructed predictive models showed overall accuracies of over 78% and 87% for differentiating ETEC and PRRS, respectively, whereas the models did not accurately predict S. suis infection. Conclusions: Salivary analytes show different changes in pigs depending on the disease, and the combination of these analytes can contribute to the prediction of different diseases. Further studies should be conducted in larger populations to confirm these findings and evaluate their possible practical applications. Full article

Background and Objectives: Assessing pain deception is challenging due to its subjective nature. The main goal of this study was to evaluate the diagnostic value of pain deception using machine learning (ML) analysis with the Minnesota Multiphasic Personality Inventory-2 (MMPI-2) scales, considering accuracy, precision, recall, and f1-score as diagnostic parameters. Materials and Methods: This study was a single-blinded, randomized controlled trial. Subjects were randomly allocated into a non-deception (ND) group and a deception (D) group. Pain deception, as a form of psychological intervention, was taught to subjects in the D group to deceive the physician. MMPI-2, Waddell’s sign, and salivary alpha-amylase (SAA) were also measured. For analyzing the MMPI-2, the XGBoost ML algorithm was applied. Results: Of a total of 96 participants, 50 and 46 were assigned to the ND group and the D group, respectively. In the logistic regression analysis, pain and MMPI-2 did not show diagnostic value. However, in the ML analysis, values of the selected MMPI-2 (sMMPI-2) scales related to pain deception showed an accuracy of 0.724, a precision of 0.692, a recall of 0.692, and an f1-score of 0.692. Conclusions: Using MMPI-2 test results, ML can diagnose pain deception better than the conventional logistic regression analysis method by considering different scales and patterns together. Full article