DNA extraction and highthroughput sequencing
Vaginal secretions were collected from mice and patients in each group, and bacterial genomic DNA was extracted according to the instructions for use of DNA kit from Tiangen Biotech Co., Ltd. The nano drop spectrophotometer (NanoDrop; Thermo Fisher Scientifc, Inc.) to measure the concentration and quality of DNA. The 16 S ribosomal DNA (rDNA) V4 region was amplified using primers (F, AYTGGGYDTAAAGNG; R, TACNVGGGTATCTAATCC) in each sample, and the Q-PCR products were sequenced on the IlluminaHiSeq 2000 platform (GenBank accession number PRJNA 882,985 and PRJNA 883,005). Amplicon generation and sequencing were completed in PersonalbioCo., Ltd. (Shanghai, China).