Saliva is an emerging biofluid with a significant number of applications in use across research and clinical settings. The present paper explores the reasons why saliva has grown in popularity in recent years, balancing both the potential strengths and weaknesses of this biofluid. Focusing on reasons why saliva is different from other common biological fluids such as blood, urine, or tears, we review how saliva is easily obtained, with minimal risk to the donor, and reduced costs for collection, transportation, and analysis. We then move on to a brief review of the history and progress in rapid salivary testing, again reviewing the strengths and weaknesses of rapid immunoassays (e.g., lateral flow immunoassay) compared to more traditional immunoassays. We consider the potential for saliva as an alternative biofluid in a setting where rapid results are important. We focus the review on salivary tests for small molecule biomarkers using cortisol as an example. Such salivary tests can be applied readily in a variety of settings and for specific measurement purposes, providing researchers and clinicians with opportunities to assess biomarkers in real time with lower transportation, collection, and analysis costs, faster turnaround time, and minimal training requirements. We conclude with a note of cautious optimism that the field will soon gain the ability to collect and analyze salivary specimens at any location and return viable results within minutes.

Laboratory stress tasks such as the Trier Social Stress Test (TSST) have provided a key piece to the puzzle for how psychosocial stress impacts the hypothalamic-pituitary-adrenal axis, other stress-responsive biomarkers, and ultimately wellbeing. These tasks are thought to work through biopsychosocial processes, specifically social evaluative threat and the uncontrollability heighten situational demands. The present study integrated an experimental modification to the design of the TSST to probe whether additional social evaluative threat, via negative verbal feedback about speech performance, can further alter stress reactivity in 63 men and women. This TSST study confirmed previous findings related to stress reactivity and stress recovery but extended this literature in several ways. First, we showed that additional social evaluative threat components, mid-task following the speech portion of the TSST, were still capable of enhancing the psychosocial stressor. Second, we considered stress-reactive hormones beyond cortisol to include dehydroepiandrosterone (DHEA) and testosterone, and found these hormones were also stress-responsive, and their release was coupled with one another. Third, we explored whether gain- and loss-framing incentive instructions, meant to influence performance motivation by enhancing the personal relevance of task performance, impacted hormonal reactivity. Results showed that each hormone was stress reactive and further had different responses to the modified TSST compared to the original TSST. Beyond the utility of showing how the TSST can be modified with heightened social evaluative threat and incentive-framing instructions, this study informs about how these three stress-responsive hormones have differential responses to the demands of a challenge and a stressor.

Purpose Saliva is a reliable, noninvasive, and cost-effective alternative to biomarkers measured in other biological fluids. Within certain populations, saliva sampling may be difficult because of insufficient saliva flow, which may compromise disease diagnosis or research integrity. Methods to improve flow rates (eg, administering citric acid, chewing gum, or collecting cotton) may compromise biomarker integrity, especially if the methods involve the presence of a collection aid in the oral cavity. Anecdotal strategies (eg, looking at pictures of food or imagining food) have not been evaluated to date. In this study, we evaluate whether 2 novel collection techniques improve saliva flow or interfere with assay of common biomarkers (ie, cortisol, dehydroepiandrosterone, and testosterone). We evaluate an over-the-counter anhydrous crystalline maltose lozenge intended to increase saliva production for patients with xerostomia long after the lozenge dissolves. We then evaluate whether the smell of freshly cooked bacon stimulates a pavlovian-type reflex. Methods Saliva was collected from 27 healthy young adults (aged 20-34 years; 12 men) on a basal day and a lozenge day, providing 5 samples at 15-minute intervals. Twenty participants then returned for the bacon day condition, providing 2 saliva samples with an interval of 15 minutes between samples. Collection times required to generate 2 mL of saliva across collection strategies were recorded, and then saliva samples were assayed for cortisol, dehydroepiandrosterone, and testosterone. Findings Repeated analysis of variance measures revealed that both the lozenges and bacon significantly decreased collection time compared with the passive drool collection on the basal day. No significant effects were found related to the quantification of cortisol, testosterone, or dehydroepiandrosterone when comparing lozenge or bacon to the basal day. In addition, bivariate correlations revealed that concentrations from time-matched control samples correlated significantly with concentrations from the lozenge and bacon conditions. Implications These results indicate that both the lozenge and smelling bacon improve saliva collection times and that neither technique interferes with salivary hormone concentrations. This study reveals new methods to augment saliva collection strategies.

No abstract

No abstract