AUTHOR=Li Ting , Liu Zhaohui , Zhang Xu , Chen Xi , Wang Suxia 

TITLE=Local Probiotic Lactobacillus crispatus and Lactobacillus delbrueckii Exhibit Strong Antifungal Effects Against Vulvovaginal Candidiasis in a Rat Model

JOURNAL=Frontiers in Microbiology

VOLUME=10

YEAR=2019

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2019.01033

DOI=10.3389/fmicb.2019.01033

ISSN=1664-302X

ABSTRACT=<p>A comprehensive knowledge of the vaginal ecosystem is critical for the development of successful approaches to the treatment of infections. The role of <italic>Lactobacilli</italic> in preventing vulvovaginal candidiasis (VVC) is controversial. In this study, we investigated the therapeutic effects and mechanism of <italic>Lactobacillus crispatus</italic> or <italic>delbrueckii</italic> on vaginitis caused by <italic>Candida albicans</italic> in a Sprague–Dawley rat model. A microbiological evaluation was performed by Gram staining and fungal colonies were enumerated. The antifungal efficacy of the two <italic>Lactobacillus</italic> strains was assessed by hematoxylin and eosin (HE) staining, transmission electron microscopy (TEM), immunohistochemical detection of interferon-γ (IFN-γ), interleukin (IL)-4, IL-17, and epithelial-derived IgG (RP125). Our <italic>in vitro</italic> results showed that the inhibitory activity against <italic>Candida</italic> colony-forming unit (CFU) counts was demonstrated by the two <italic>Lactobacillus</italic> strains (<italic>P</italic> &lt; 0.001). Our results indicated that <italic>Lactobacillus</italic> administration played an indispensable role in maintaining the immune homeostasis, and decreasing the Th1/Th2 ratio (IFN-γ/IL-4) by regulating the epithelial secretion of cytokines that inhibit epithelial proinflammatory cytokine release, while increasing epithelial-derived IgG expression (<italic>P</italic> &lt; 0.05), suggesting antibody-mediated protection. Our results implicate <italic>L. crispatus</italic> and <italic>L. delbrueckii</italic> as a potential adjunct biotherapeutic agent in women with VVC, especially for those with drug resistance, adverse effects or contraindications when using antifungal agents. Further large, long-term, well-planned clinical studies should be performed in clinical practice to determine their clinical potential of <italic>L. crispatus</italic> and <italic>L. delbrueckii</italic> as an adjunct treatment for VVC.</p>