This single-center, randomized, single-blind, placebo-controlled trial aimed to evaluate the efficacy and safety of oral Lactobacillus crispatus Lc-G22 as adjunctive therapy to clotrimazole for preventing recurrence of vulvovaginal candidiasis (VVC). One hundred women aged 18-50 years with a history of ≥2 VVC episodes and current positive fungal microscopy were randomized 1:1 to receive clotrimazole vaginal tablets plus oral Lc-G22 (5×10⁹ CFU, twice daily for 60 days) or clotrimazole plus matching placebo. The primary outcome was overall clinical response rate at Month 3. Secondary outcomes included mycological negativity rate, VVC clinical scores, vaginal microecological parameters, and cumulative recurrence rate over 12 months. Safety was assessed by adverse event incidence.