Published in Scientific Reports, the double-blind randomized clinical trial involving 59 premenopausal and menopausal women (aged 40-60) concluded Lactobacillus acidophilus supplementation may improve desire, arousal, satisfaction, as well as total Female Sexual Function Index (FSFI) and quality of life (QoL) scores.
“Probiotics may serve as a safe and non-hormonal option for enhancing women’s health during the menopausal transition. However, for issues related to mucosal atrophy, such as vaginal dryness and pain, targeted local treatments remain necessary,” the report said.
Menopause and sexual dysfunction
Menopause is a time when women’s hormones shift and estrogen levels reduce, which can lead to symptoms such as hot flashes, sweating, headaches, musculoskeletal pain, mood swings, cognitive changes, decreased sexual desire, adverse metabolic changes, sleep disturbances, and genitourinary discomfort.
Female Sexual Dysfunction (FSD) is a broad term encompassing various aspects of sexual desire, arousal, orgasm, and/or pain. Persistent and recurrent problems in any of these domains, which cause distress to the patient or impair her relationship with her partner, are recognized as sexual dysfunction.
The prevalence of sexual dysfunction among postmenopausal women varies widely worldwide, ranging from 68% to 86.5% in certain regions.
Emerging evidence indicates that probiotics can influence estrogen metabolism via gut-microbiota pathways and alleviate menopausal symptoms without the adverse effects associated with hormone therapy.
Vaginal microbiota, particularly Lactobacillus species, are beneficial for female reproductive health, but their abundance declines due to hormonal and epithelial changes during menopause, and lactic acid concentration in vaginal fluid also declines.
Lactobacillus acidophilus has been widely used in vaginal and oral probiotic formulations due to its safety profile and ability to produce lactic acid, hydrogen peroxide, and other antimicrobial compounds, which help maintain vaginal eubiosis and inhibit pathogenic microorganisms. However, direct evidence of its benefits in postmenopausal women has remained limited.
Study details
Participants recruited from health centers in Tabriz, Iran, were randomly assigned to the probiotic and placebo groups. The probiotic group received a 250 mg capsule containing 3 × 109 CFU/cap of Lactobacillus acidophilus, while the placebo group received a 250 mg capsule of corn starch once daily for eight weeks.
The Female Sexual Function Index (FSFI) and the Menopause Quality of Life (MENQoL) questionnaire were completed before and eight weeks after the intervention.
At baseline, there were no significant differences between the two groups in terms of desire, arousal, lubrication, satisfaction, pain, orgasm, and total FSFI score.
After the intervention, the probiotic group showed a significant improvement in desire and arousal compared to the placebo group.
The probiotic group had a significantly higher total FSFI score compared with the placebo group, considered both statistically and clinically meaningful.
Also, the total MENQoL score was significantly lower (which is a positive) in the probiotic group compared with placebo group.
In contrast, lubrication was significantly higher in the placebo group after the intervention. Moreover, satisfaction scores improved significantly in the probiotic group, compared with placebo.
No significant differences were observed in orgasm and pain domains after the intervention.
Study limitations noted in the report include the small sample size, short intervention window, the use of self-reported questionnaires, which may be subject to placebo effects or response bias.
Future research with larger sample sizes, longer intervention durations, and integration of objective biological assessments is recommended to better elucidate the mechanisms and long-term clinical significance of probiotic supplementation in menopausal women.
Source: Scientific Reports 16, 1254 (2026). https://doi.org/10.1038/s41598-025-30879-5, “The effect of probiotic supplementation on sexual function in premenopausal and menopausal women: a randomized controlled clinical trial”, Authors: Valizadeh, R., Borhani, F., Shabani, F. et al.
