Saccharomyces cerevisiae-based probiotic as novel anti-fungal and anti-inflammatory agent for therapy of vaginal candidiasis.

E Gabrielli,P Jüsten,P Mosci,F Pélerin,A Vecchiarelli,A Cayzeele Decherf,S Perito,E Roselletti,N Ballet,E Pericolini,S Sabbatini

doi:10.3920/bm2017.0099

Abstract

Previously we demonstrated that the treatment with live Saccharomyces cerevisiae exerts beneficial therapeutic effects against vaginal candidiasis. Here, we address potential mechanisms particularly examining the probiotic capacity to modulate both fungus and host-related factors. We show that the S. cerevisiae-based probiotic markedly affects the expression of virulence traits of Candida albicans such as aspartyl proteinases (SAPs) as well as hyphae-associated proteins Hwp1 and Ece1 in the vaginal cavity. On the host side, the probiotic suppression of the influx of neutrophils caused by the fungus into the vaginas of the mice is likely related to: (1) lower production of interleukin-8; and (2) inhibition of SAPs expression. However, these neutrophils displayed reactive oxygen species hyperproduction and increased killing activity as compared to the neutrophils of placebo-treated mice. There was no evidence of any cytotoxic effect by the probiotic, either when used in vivo on vaginal epithelial cell and organ architecture, or in in vitro in human vaginal epithelium. Inactivated yeast cells did not affect any of the factors above. In summary, the data suggest that the beneficial effect exerted by this S. cerevisiae-based probiotic is the result of its interference with the expression of fungus virulence factors coupled with the modulation of the inflammatory response of the host.

Highlights

Probiotics are living microbial preparations able to provide health benefits to the host by affecting microbiota balance, composition and activity
We have expanded on the effects of this S. cerevisiae-based probiotic (GI) on the expression of pathogenicity determinants by C. albicans in vivo during vaginal candidiasis; in addition, we examined whether the administration of S. cerevisiae could dampen local inflammation by affecting the number and functions of a landmark sign of inflammation, such as neutrophil (PMN) influx
In this study, we focused on Sap2 and Sap6 that are strictly associated to immunopathogenic process of vaginal candidiasis

Summary

Introduction

Probiotics are living microbial preparations able to provide health benefits to the host by affecting microbiota balance, composition and activity. Improvements of the immune function in probiotic-treated hosts appear to be related to the burden of the beneficial bacterial population and to the capacity of some of the metabolites secreted by these bacteria to modify the expression of basic functions of immune cells, such as cytokine production. This is clearly observed in the intestinal epithelium. Differential effects of short-chain fatty acids on proliferation and production of pro- and anti-inflammatory cytokines by cultured lymphocytes (Cavaglieri et al, 2003) could be a consequence of direct interaction of some bacterial cell surface components such as lipoteichoic acids and lipopolysaccharides with pattern recognition receptors

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