New techniques for augmenting saliva collection: bacon rules and lozenge drools

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.

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.

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.

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.