Inhibitory effect of Lactobacillus fermentum SNUV175 and Lactobacillus crispatus SNUV220 isolated from healthy Korean women on vulvovaginal candidiasis

Abstract

Lactobacillus spp. is commensal microbiota in vaginal environment known to inhibit pathogen growth by producing anti-microbial compounds. we isolated Lactobacillus fermentum SNUV175 and Lactobacillus crispatus SNUV220 strains from Korean healthy women vagina. In this study we investigated how Lactobacillus species interact with vaginal pathogen C. albicans. We used Lactobacillus cell-free supernatant (LCS) to demonstrate growth inhibiting effect. Interestingly, we found that not only LCS effectively inhibited C. albicans growth in vitro and in vivo level, but also yeast-hyphae transition known as virulence factor of vulvovaginal candidiasis. To know how LCS affect C. albicans growth and hyphae transition, we analyzed gene expression level of C. albicans in hyphal inducing condition. Such as SAP5, HWP1, ECE1, ALS3 gene related to hyphal and toxin production were downregulated significantly in mRNA level. Through the metabolomic analysis using UPLC-QTOF, we investigated in Lactobacillus cell-free supernatant were significantly increased.

Our study suggests that L. fermentum and L. cristpatus cell-free supernatant result in suppression of C. albicans growth and decreased virulence of C. albicans in vitro and in vivo level. Further, we performed mass spectrometric analysis to identify potential inhibitory molecule. In conclusion, we confirm that Lactobacillus cell-free supernatant prevent infection and inhibit C. albicans overgrowth.