Saccharomyces cerevisiae, a yeast widely employed in food and pharmaceutical industries, has a proven probiotic activity and it is used to treat several infections by the opportunistic pathogen Candida albicans.
With this project we aimed at assessing if cell-free supernatants (CFS) from 3 different fecal isolates and from 1 ATCC strain of S. cerevisiae could maintain the anti-Candida effect. We evaluated C. albicans growth inhibition through CFU, the impairment of virulence factors (adhesion, biofilm formation and metabolic activity) by crystal violet and XTT assays, and the antifungal effect in combination with antifungal drugs by evaluating the MIC. An untargeted metabolomic analysis was also performed in the CFS.
Our preliminary results show that the CFS have little effect on C. albicans viability, but they can impair C. albicans virulence traits, such as adhesion, biofilm formation and metabolic activity.
Studies are being carried out to assess if the combination of CFS and antifungal drugs can potentiate the latter. The untargeted metabolomic analysis indicated an overexpression of metabolites implied in the pathway of tryptophan biosynthesis in all the CFS from fecal isolates as compared to the reference strain.
Further studies are warranted to better characterize these CFS with the aim of employing them as a postbiotic aid to the current antifungal therapy.
Prof. Andrea Ardizzoni
December 1st, 2025