Vaginal Lactobacillus Detection and Urinary Findings During Synbiotic Supplementation in Pregnancy: An Exploratory Prospective Study

Background/Objectives: The vaginal and urinary tracts form an interconnected urogenital ecosystem. Oral probiotics have shown benefit in pregnancy for selected outcomes, including bacterial vaginosis and Group B Streptococcus agalactiae (GBS) colonization. However, their effects on vaginal Lactobacillus composition appear to be strain-specific. This prospective exploratory single-arm study evaluated whether vaginal Lactobacillus detection and routine urinary parameters changed during 60 days of oral multi-strain synbiotic supplementation in pregnant women with abnormal urinalysis. Methods: Twenty pregnant women at 28–32 weeks of gestation with abnormal routine urinalysis (leukocyturia, hematuria, and/or reported bacterial flora) received a multi-strain synbiotic containing seven probiotic strains and inulin twice daily for 60 days. Vaginal detection of L. crispatus, L. reuteri, L. rhamnosus, L. gasseri (supplement species), and L. jensenii (comparator) was assessed by species-specific real-time PCR at baseline (T0) and after 60 days (T1). Routine urinalysis was recorded at both times, and GBS colonization status at T1. Paired comparisons used McNemar’s exact and Wilcoxon tests; all analyses were exploratory. Results: Bacterial flora on urinalysis decreased from 20/20 (100%) to 8/20 (40%) (p < 0.001). Urinary pH, leukocyte and epithelial cell counts did not change significantly. Vaginal L. reuteri detection increased (2/20 to 10/20; p = 0.008). Four women (20%) were GBS-positive at T1. Conclusions: During 60 days of oral multi-strain synbiotic supplementation, temporal changes were observed in reported urinary bacterial flora and vaginal detection of selected Lactobacillus species. These exploratory findings require confirmation in larger controlled studies.