Common Probiotic, Lactobacillus, May Prevent UTIs

Researchers found that vaginal suppositories containing Lactobacillus, a type of "good" bacteria found in the gut, mouth, and vagina, may help reduce the number of urinary tract infections in postmenopausal women.

Recurrent urinary tract infections, or recurrent cystitis (RC), are defined as two or more infections in six months or three or more in a year. While UTIs are common — impacting up to 50% of all women in their lifetime — research shows that postmenopausal women are disproportionately affected.

This is likely because of hormonal changes that alter the microbiome in the urinary and genital tract.

During a UTI, pathogenic bacteria such as E. coli increase in the bladder, while at the same time, beneficial bacteria like Lactobacilli decrease. Typically, preventing recurrent UTIs involves intermittent or continuous use of low-dose antibiotics. However, some research has found that vaginal suppositories containing Lactobacillus may help prevent recurring UTIs.

Yet, it’s unclear whether these suppositories could also help prevent infections in women who have gone through menopause.

In a study recently published in Frontiers in Microbiology, researchers from the Okayama University Hospital, Okayama, Japan, investigated menopause-related changes in the vaginal microbiome and whether Lactobacillus crispatus (L. crispatus)-containing vaginal suppositories could reduce or prevent recurring UTIs in postmenopausal women.

To conduct the study, the scientists used gene-based sequencing to compare the vaginal microbiomes of 39 postmenopausal women. They classified the participants into one of four groups:

• Healthy women
• Women experiencing recurrent UTIs
• Women with uncomplicated UTIs
• Women already using Lactobacillus-containing vaginal suppositories for recurrent UTI prevention.

The sequencing found that bacterial species differed significantly between the healthy and the uncomplicated UTI groups. In addition, the uncomplicated UTI and the healthy groups had distinctly different microbiomes than the participants with recurring UTIs.

Moreover, the researchers noticed similarities in bacterial species but differences in variation and abundances in the vaginal microbiomes of the recurrent UTI group and the participants who already used Lactobacillus-containing vaginal suppositories.

However, they also found that postmenopausal women with recurring UTIs had virtually no detectable Lactobacillus in the vaginal tract. Instead, they found that these participants had more harmful bacterial species belonging to the Enterobacteriaceae family.

But after the administration of L. crispatus-containing suppositories, the abundance of this beneficial bacteria increased to 19%, and the women experienced fewer UTIs. Specifically, suppository use reduced UTI episodes from 6.3 to 2.4 per year.

Though the study used a small number of participants, the authors say that treating postmenopausal women who experience recurrent UTIs with L. crispatus-containing suppositories may be an effective strategy to prevent infections without the need for continuous low-dose antibiotics. And this is important because frequent use of antibiotics may lead to bacterial resistance, resulting in infections that are more challenging to treat.