Differences in Vaginal Microbiota Composition Between Infertile and Fertile Patients: A Prospective Study.

Area of Science:

• Microbiology
• Reproductive Health
• Genetics

Background:

• Vaginal microbiota dysbiosis, marked by reduced Lactobacillus spp., is linked to female infertility.
• Community State Type (CST) IV is underexplored in relation to infertility.
• This study focuses on comparing CST IVA and IVB between fertile and infertile women.

Purpose of the Study:

• To compare the vaginal microbiota composition, specifically CST IVA and IVB, between fertile and infertile women.
• To investigate the association between specific microbial profiles and female infertility.
• To identify potential microbial biomarkers for infertility.

Main Methods:

• Prospective study involving 22 women (15 infertile, 7 fertile).
• Vaginal samples analyzed using 16S rRNA gene sequencing (V3-V4 regions) on the Illumina MiSeq platform.
• Taxonomic classification performed with QIIME 2; statistical analysis using Wilcoxon rank-sum test.

Main Results:

• Infertile women exhibited lower relative abundance of Lactobacillus spp. and Oscillospira spp.
• CST IV was more prevalent in infertile women (29.75% vs. 21.61%).
• CST IVA was disproportionately higher in infertile women (7.0% vs. 0.94%), characterized by a significant increase in Prevotella spp. (95.18% vs. 69.77%).

Conclusions:

• Elevated Prevotella spp. within CST IVA may create an unfavorable vaginal environment, potentially impairing sperm viability and contributing to infertility.
• The presence of Oscillospira spp. is associated with a healthy vaginal microbiota profile in fertile women.
• Further research into CST IV subtypes is crucial for understanding female infertility.