An effective salivation-facilitating method for COVID-19 testing: An experimental study

Simple tools, such as antigen test kits, are readily available for determining coronavirus disease 2019 infection at hospitals and homes. However, it is challenging for elderly people who are prone to dry mouth and other diseases. The main objective of this study was to investigate whether the presence or consumption of a plum pickle can facilitate salivation during coronavirus disease 2019 testing.

Twenty healthy adult women participated in the study. The participants were allocated to 2 groups: presentation and non-presentation (n = 10; with and without presentation of a plum pickle, respectively), and eating and non-eating (n = 10; with and without consumption of plum pickle, respectively). We recorded the number of saliva swallows in 1 minute under each condition, using a swallowing test device, which attached film sensors to the hyoid bone and thyroid cartilage.

There was a significant difference in the number of swallows between the non-presentation and presentation groups ( P < .01, r = 0.89, Z = -2.82) as well as between the non-eating and eating groups ( P < .01, r = 0.85, Z = -2.68).

The strength of 3 factors, namely: direct stimulation with citric acid, saliva buffer capacity, and motor learning, may have affected the results. Our study suggests that saliva collection using the plum pickle is an effective complementary method for facilitating salivation. This technique may be useful in avoiding the risk associated with citric acid intake and for efficient specimen collection during coronavirus disease 2019 testing. In the future, we need to verify this method in elderly participants in a clinical setting.