Relationship between salivary histatin 5 levels and Candida CFU counts in healthy elderly

Objectives: Few epidemiological studies have confirmed the antifungal activity of histatin 5 in saliva against Candida species. The purpose of this study was to examine the relationship between concentrations of histatin 5 and the number of cultivable Candida in saliva samples from elderly. Methods: Whole saliva samples were obtained from 124 elderly people, 65 years or older, living in a rural community. The concentrations of histatin 5 in saliva samples were determined by the enzyme‐linked immunosorbent assay (ELISA) using a monoclonal antibody. Total colony‐forming units (CFUs) were counted on a selective medium for Candida. Multiple linear regression analysis was performed to determine the independent contribution of explanatory variables to Candida CFUs using age, sex, histatin 5 concentration and type of denture prosthesis as independent variables. Results: Saliva samples from 104 subjects (84%) were candidal colony‐positive. The youngest group (65–69 years old) showed significantly smaller Candida CFU counts than those in the older group. The mean Candida CFU count of denture wearers was significantly higher than that of non‐denture wearers. Significantly negative associations were found between Candida CFU counts and histatin 5 level in the oldest group (p < 0.05) and in the full‐denture wearers (p < 0.01). Multiple linear regression analysis revealed that Candida CFU counts were mostly associated with type of dentures, followed by histatin 5 concentration. Conclusion: Possible activity of histatin 5 against Candida in whole saliva of elderly people was epidemiologically confirmed. The area covered by the prostheses was a strong factor associated with the Candida CFU count.