Menopausal hormone therapy may boost beneficial bacteria in vaginal microbial community

Postmenopausal women who use menopausal hormone therapy (MHT) appear to have increased Lactobacillus abundance and lower vaginal microbial community diversity, according to a study.

The cross-sectional study included 94 women between 40 and 60 years of age, among whom 32 were premenopausal, 30 were postmenopausal, and 32 were postmenopausal and receiving MHT orally (postmenopausal+MHT group). Neither women in the premenopausal nor those in the postmenopausal group received hormone therapy within the past 6 months. Postmenopausal women who received vaginal MHT were not included.

Researchers collected vaginal swabs, from which microbial composition was characterized using 16S rRNA gene sequencing targeting the V3 to V4 region. Clinical data were recorded, and serum sex hormones were measured. The most bothersome symptom approach and vaginal health index were used to evaluate genitourinary syndrome of menopause (GSM).

Compared with premenopausal women, postmenopausal women had a vaginal microbial community characterized by a decreased abundance of Lactobacillus (18 percent in the postmenopausal group vs 69 percent in the premenopausal group), an increased abundance of several anaerobic bacteria (ie, Prevotella, Escherichia-Shigella, and Bifidobacterium), and a higher microbial diversity (p<0.001).

In postmenopausal women who received MHT, the vaginal microbial community had an increased abundance of Lactobacillus (54 percent) and lower microbial diversity (p<0.001) compared with that in the postmenopausal women.

Additionally, the vaginal microbial community composition of the postmenopausal+MHT group was more similar to that of the premenopausal group (p=0.051) than with that of the postmenopausal group (p<0.001).

Of note, a decreased abundance of Lactobacillus and high diversity in the vaginal microbial community were observed in women with moderate-to-severe GSM symptoms.