Effect of Vaginal Microecological Alterations on Female Pelvic Organ Prolapse

Abstract

Introduction and hypothesis: The objective was to investigate the correlation between endogenous vaginal microecological alterations and female pelvic organ prolapse (POP).

Methods: Patients who underwent vaginal hysterectomy were retrospectively analyzed as the POP group (n = 30) and the non-POP group (n = 30). The vaginal microbial metabolites and enzyme levels were tested using the dry chemoenzymatic method. The mRNA and protein expression were tested using real-time quantitative PCR and immunohistochemistry. SPSS version 25.0 and GraphPad Prism 8.0 were performed for statistical analysis.

Results: Compared with the non-POP group, the vaginal pH, H₂O₂ positivity and leukocyte esterase positivity were higher in patients with POP (all p < 0.05). Further analysis showed that patients with pelvic organ prolapse quantification (POP-Q) stage IV had higher rates of vaginal pH, H₂O₂ positivity and leukocyte esterase positivity than those with POP-Q stage III. Additionally, the mRNA expression of decorin (DCN), transforming growth factor beta 1 (TGF-β1), and matrix metalloproteinase-3 (MMP-3) in uterosacral ligament tissues were higher, whereas collagen I and III were lower. Similarly, the positive expression of MMP-3 in uterosacral ligament tissue was significantly upregulated in the POP group compared with the non-POP group (p = 0.035), whereas collagen I (p = 0.004) and collagen III (p = 0.019) in uterosacral ligament tissue were significantly downregulated in the POP group. Correlation analysis revealed that there was a significant correlation between vaginal microecology and collagen metabolism. In addition, MMP-3 correlated negatively with collagen I and collagen III (p = 0.002, r = -0.533; p = 0.002, r = -0.534 respectively), whereas collagen I correlated positively with collagen III (p = 0.001, r = 0.578).

Conclusions: Vaginal microecological dysbiosis affects the occurrence of female POP, which could be considered a novel therapeutic option.

Keywords: Collagen I; Collagen III; Matrix metalloproteinase-3; Pelvic organ prolapse; Vaginal microbiome.

Fig. 1

The mRNA expression levels of A decorin (DCN), B transforming growth factor beta 1 (TGF-β1), C matrix metalloproteinase-3 (MMP-3), D collagen I, and E collagen III in tissue samples from the uterosacral ligament were quantified using quantitative polymerase chain reaction in patients with pelvic organ prolapse (POP) and non-POP. Statistical analysis revealed significant differences between the two groups (*p < 0.05, ***p < 0.001)

Fig. 2

Matrix metalloproteinase-3 (MMP-3) is significantly upregulated in pelvic organ prolapse (POP). Tissue sections were subjected to A hematoxylin and eosin (HE) staining and B immunohistochemistry analysis for MMP-3 expression in both POP and non-POP tissues (bar, 50 μm). *p < 0.05

Fig. 3

Collagen I expression is significantly lower in pelvic organ prolapse (POP) than in non-POP. Tissue samples were A stained with hematoxylin and eosin (HE) and B subjected to immunohistochemistry analysis for collagen I expression. (bar, 50 μm). **p < 0.01

Fig. 4

Collagen III expression is significantly lower in pelvic organ prolapse (POP) than in non-POP. Tissue samples were A stained with hematoxylin and eosin (HE) and B subjected to immunohistochemistry analysis for collagen III expression. (bar, 50 μm). *p < 0.05

Fig. 5

A–C Correlation of matrix metalloproteinase-3 (MMP-3), collagen I, and collagen III with clinical characteristics in patients with pelvic organ prolapse