Lactic Acid Bacteria from Kiwi: Antifungal and Biofilm-Inhibitory Activities Against Candida albicans

Urogenital infections impact millions of individuals globally each year, with vulvovaginal candidiasis (VVC) being one of the most prevalent conditions affecting women. Candida albicans is the primary pathogen responsible for VVC. The utilization of probiotics as an alternative therapeutic approach to antibiotics in managing such infections has gained increasing attention. This study aimed to evaluate the potential of THY-F51, a lactic acid bacterium isolated from kiwi, as a probiotic to support vaginal health through its antifungal, anti-biofilm, and anti-inflammatory properties against C. albicans. The identification of THY-F51 was confirmed through 16S rRNA gene sequencing. A series of evaluations were performed to determine its antifungal efficacy against C. albicans, biofilm-inhibitory activity, antioxidant properties, and effects on inflammatory cytokines. Cytotoxicity assays and assessments of bacterial survival under vaginal pH conditions (pH 3.8–4.5) were also conducted. The results demonstrated that THY-F51, identified as Leuconostoc citreum, exhibited potent antifungal activity against C. albicans, with an MIC of 1.25 mg/mL and an MFC of 2.5 mg/mL. Furthermore, THY-F51 displayed a strong inhibition of C. albicans biofilm formation, as well as notable antioxidant activity in the supernatant. Additionally, THY-F51 demonstrated high survival rates under vaginal pH conditions, an absence of cytotoxic effects, and a significant reduction in C. albicans adhesion to HeLa cells. Moreover, THY-F51 effectively suppressed C. albicans-induced inflammatory cytokines, including TNF-α, IL-1β, IL-6, and IL-8. These findings suggest that THY-F51, isolated from kiwi, holds substantial promise as a safe and effective probiotic for reducing vaginal inflammation and promoting vaginal health.