Summary
Recurrent urinary tract infections (rUTIs) are a burden to patients and the health care economy. Vaginal probiotics and supplements have gained significant attention in mainstream media and lay press as a non-antibiotic alternative. Recently, Shoureshi et al. [1] performed a systematic review to determine whether vaginal probiotics are an effective prophylactic measure for rUTI. For this, the authors performed a PubMed/MEDLINE article search (up to August 2022) seeking for prospective, in vivo use of vaginal probiotic suppositories for the prevention of rUTIs. Search terms included: vaginal probiotic suppository, vaginal probiotic randomized, vaginal probiotic prevention, vaginal probiotic UTI, and vaginal probiotic urinary tract infection. A total of 771 article titles and abstracts were screened of which 8 fit the inclusion criteria and were reviewed and summarized. Four were randomized controlled trials, with 3 of the studies having a placebo arm. Three were prospective cohort studies, and 1 was a single arm, open label trial. Five of the 7 articles that specifically evaluated for rUTI reduction with vaginal suppositories did find a decreased incidence with probiotic use; however, only 2 had results that were statistically significant. Both of the latter were studies of Lactobacillus crispatus and were not randomized. Three studies demonstrated the efficacy and safety of Lactobacillus as a vaginal suppository. The authors conclude that the current data support the use of vaginal suppositories containing Lactobacillus as a safe, non-antibiotic measure, but actual reduction of rUTI in susceptible women remains inconclusive. The appropriate dosaging and treatment duration remain unknown and more research is needed.
Commentary
Falling estrogen levels after the menopause result in changes to the vaginal and urethral epithelium and the urogenital microbiome which combine to lower the natural defence mechanisms and predispose women to rUTI. Dealing with rUTIs is a challenge for any professional managing women with the genitourinary syndrome of menopause (GSM) be they in primary care, gynaecology or urology. In postmenopausal women with a confirmed diagnosis of a UTI, the mainstay of treatment is an oral antibiotic. However, women with rUTI end up having frequent courses of antibiotics which further destabilises the gut and urogenital microbiome and increases the likelihood of developing infections with antibiotic resistant strains. Careful antibiotic stewardship is vitally important in rUTIs and the focus should be preventive. In this regard, we know that vaginal estrogens are helpful and within 12 weeks the Lactobacilli are restored with recovery of the urogenital host defences. Nevertheless, whilst vaginal estrogens should be regarded as a mainstay of treatment, they are not always sufficient on their own and not an option for everyone. Long term prophylactic low dose antibiotics can be very helpful, but there is increasing interest in non-antibiotic alternatives.
The importance of the vaginal and urinary microbiome in the pathogenesis of UTIs among postmenopausal women is increasingly being recognized as previously Yang and Brubaker have highlighted [2].
The healthy premenopausal vagina is largely colonised by Lactobacilli which form a protective vaginal microbiome by fermenting glycogen and creating lactic acid which is inhibitory to other bacteria. Lactobacilli also prevent the adherence of uropathogens to the vaginal epithelium. After the menopause there is a loss of epithelial glycogen production which in turn leads to less lactic acid production by the lactobacilli. This results in an elevated pH which the vaginal environment more vulnerable to uropathogens and subsequent infection. There is increasing public interest in probiotics which resonates with many women as they prefer to self-manage with natural products rather than see a health care professional. However, many of the claims for probiotics are not backed up with robust scientific evidence so this recent systematic review from the Cedar-Sinai Medical Centre Urology department in Los Angeles, US [1] is helpful in understanding the potential role of probiotics. They found that there is some support for the use of Lactobacilli vaginal probiotics in preventing rUTIs but this was not confirmed in a randomized trial. The authors emphasize that there were no reported serious adverse effects from using vaginal probiotics. The article also highlights that there is a heterogeneity amongst the lactobacilli species and this raises the question of whether some species are more effective than others. Lactobacillus crispatus for instance produces the most lactic acid and thus may be more effective.
To me this article highlights that there may well be some benefit with vaginal probiotics in the prevention of rUTIs and there appears to be no obvious harm for their use but more data are needed and not all probiotics are the same.
Tim Hillard, DM FRCOG
Department of Gynaecology, University Hospitals Dorset, Poole, UK
Editor in Chief, Climacteric
References
- Shoureshi PS, Niino C, Eilber KS. Can vaginal lactobacillus suppositories help reduce urinary tract infections? Int Urogynecol J. 2023;34(11):2713-2718.
https://pubmed.ncbi.nlm.nih.gov/37392226/ - Jung C, Brubaker L The etiology and management of recurrent urinary tract infections in post-menopausal women. Climacteric. 2019;22(3):242–249.
https://doi.org/10.1080/13697137.2018.1551871
If you would like to add a comment or contribute to a discussion based on this issue, please contact Menopause Live Editor, Peter Chedraui, at peter.chedraui@cu.ucsg.edu.ec.
