Prevalence of Vaginal Lactobacillus Species and Its Relationship to Bacterial Vaginosis in Women of Reproductive Age in Calabar, Cross River State

The vaginal microbiome, particularly the composition and dominance of Lactobacillus species, plays a critical role in maintaining reproductive health and preventing bacterial vaginosis (BV). This cross-sectional study investigated the prevalence of vaginal Lactobacillus species and its relationship to BV in women of reproductive age attending gynecological outpatient clinics at the University of Calabar Teaching Hospital, Cross River State, in the South South geopolitical zone of Nigeria. High vaginal swab samples were collected from 150 consenting women aged 18 to 49 years. Bacterial vaginosis diagnosis was established using Nugent scoring of Gram-stained vaginal smears. Lactobacillus species identification was performed using selective MRS agar culture and API 50 CHL biochemical identification strips. Overall BV prevalence was 36.7 percent. Lactobacillus crispatus and Lactobacillus iners were the most predominant species in healthy women. Women with BV had significantly reduced Lactobacillus dominance, with Gardnerella vaginalis and anaerobic Gram-negative rods predominating. BV was significantly associated with multiple sexual partners and recent antibiotic use. The study highlights the protective role of Lactobacillus dominance in the vaginal ecosystem and recommends microbiome-aware approaches to BV management, including avoidance of routine antibiotic overuse in gynecological practice. Keywords: bacterial vaginosis, Lactobacillus, vaginal microbiome, Calabar, reproductive health.