S. cerevisiae var. boulardii yeasts, historically recognized as a separate species, are now considered a subspecies of S. cerevisiae. Strains of S. cerevisiae var. boulardii are widely used for prevention and treatment of disorders of human digestive system. The use of preparations based on S. cerevisiae var. boulardii impacts the functioning of the intestinal barrier, which leads to a change in the composition of the digestive tract microbiota and alleviates intestinal epithelial defects. Despite the clinically confirmed probiotic properties of these unicellular microorganisms, the number of reports of infections in humans has been increasing. Population studies suggest that S. cerevisiae yeasts are responsible for 0.1–3.6% of all cases of mycoses in patients receiving therapy with probiotics containing S. cerevisiae var. boulardii. The presence of a central venous catheter, parenteral nutrition, immunosuppression and co-morbidities in patients are considered as factors predisposing for infection. This work summarizes the most important information on biology of S. cerevisiae var. boulardii and presents the latest epidemiological data on fungemia caused by these fungi.
1. Introduction. 2. Applications of S. cerevisiae yeasts. 3. Isolation and taxonomy of probiotic yeasts S. cerevisiae var. boulardii. 4. Probiotic features of S. cerevisiae var. boulardii. 5. S. cerevisiae var. boulardii infections. 5.1. Review of S. cerevisiae var. boulardii fungemia cases. 6. Conclusions
