Anti-Cariogenic Effects of S. cerevisiae and S. boulardii in S. mutans-C. albicans Cross-Kingdom In Vitro Models.

Despite the well-documented health benefits of the probiotic Saccharomyces , its application in oral health has not been comprehensively assessed. Dental caries is a transmissible disease initiated by acid production of cariogenic bacteria and yeast, such as Streptococcus mutans and Candida albicans , on tooth enamel and followed by subsequent enamel demineralization. Here, we investigated the effect of two Saccharomyces strains ( Saccharomyces boulardii and Saccharomyces cerevisiae ) on S. mutans - C. albicans cross-kingdom interactions using a cariogenic planktonic model. Viable cells, pH changes, and gene expression were measured. S. cerevisiae and S. boulardii inhibited the growth of C. albicans in dual- and multi-species conditions at 4, 6, and 20 h. Saccharomyces also inhibited C. albicans hyphal formation. Furthermore, Saccharomyces reduced the acidity of the culture medium, which usually plummeted below pH 5 when S. mutans and C. albicans were present in the model. The presence of Saccharomyces maintained the culture medium above 6 even after overnight incubation, demonstrating a protective potential against dental enamel demineralization. S. boulardii significantly down-regulated S. mutans atpD and eno gene expression. Overall, our results shed light on a new promising candidate, Saccharomyces , for dental caries prevention due to its potential to create a less cariogenic environment marked by a neutral pH and reduced growth of C. albicans .