Vaginal administration of Lactobacilli may prevent recurrent cystitis in postmenopausal women

Postmenopausal women with recurrent cystitis (RC) were found to have a lack of Lactobacillus-containing vaginal suppositories compared with postmenopausal women without RC, and administration of the bacteria led to a decrease in cystitis episodes, according to data published in Frontiers in Microbiology.^1,2

For the study, 129 vaginal samples were retrospectively analyzed from 39 postmenopausal women who were aged 50 or older.

"Lactobacillus vaginal suppositories have the potential to serve as a novel preventive method for the numerous individuals suffering from recurrent cystitis, a condition that cannot be adequately cured by taking antimicrobials,” said lead author Takanori Sekito in a news release on the findings.² Sekito is a urology resident at Okayama University in Japan.

For the study, 129 vaginal samples were retrospectively analyzed from 39 postmenopausal women who were aged 50 or older. Patients were divided into 4 groups: healthy controls, patients with uncomplicated cystitis, patients with RC, and a prevention group that had received Lactobcillus crispatus-containing vaginal suppositories to prevent RC. The bacterial microbiomes present in the samples were analyzed using 16S ribosomal RNA-based gene sequencing.

Upon beta-diversity analysis, the investigators found significant differences between the microbiomes of samples from the healthy control group compared with those from the uncomplicated cystitis group (P = .045), as well as between those from the RC group compared with those from the uncomplicated cystitis (P = .001) or the healthy control group (P = .001).

Further, data showed that no Lactobacillus was present among samples from patients with RC, with the predominant taxon observed being Enterobacteriaceae. Conversely, the relative abundance of Lactobacillus was 19% among patients in the prevention group, who had received vaginal suppositories (P = .0211), making it the predominant taxon among that cohort.

Vaginal bacteria species present in samples were also analyzed before and after the administration of Lactobacillus. The microbiota of patients with RC did not return to the normal microbiota seen among healthy controls upon administration of Lactobacillus. However, a group of patients (n = 8) in the prevention group were shown to have an average of 6.3 cystitis episodes per year before administration of Lactobacillus, compared with 2.4 episodes after administration (P = .0015), thus indicating a reduction of RC.

The authors explained the mechanisms behind this finding, saying, “Vaginal administration of Lactobacillus-containing suppositories can prevent RC by stabilizing vaginal dysbiosis and causing a loss of pathogenic bacteria virulence.”

In other words, the investigators suggest that recolonization of Lactobacillus may inhibit pathogenic bacteria such as Escherichia coli, which cause an unhealthy vaginal state, thus reducing RC.

They concluded, “Importantly, our data suggest that non-antibacterial prophylaxis can be considered for patients with RC by the vaginal administration of Lactobacillus.”

References

1. Sekito T, Wada K, Ishii A, et al. Etiology of recurrent cystitis in postmenopausal women based on vaginal microbiota and the role of Lactobacillus vaginal suppository. Front Microbiol. Published online May 18, 2023. Accessed July 6, 2023. doi:10.3389/fmicb.2023.1187479

2. Vaginal suppository containing lactobacilli can prevent recurrent cystitis in women. News release. Okayama University. July 3, 2023. Accessed July 6, 2023. https://www.newswise.com/articles/lactobacilli-suppository-prevents-cystitis?ta=home