Page 39 - JCTR-11-5

Journal of Clinical and
Translational Research Vaginal microbiota in menopause pathologies

the vaginal and urinary microbiomes, as well as in local composition and richness are influenced by variables such
immunity. These synergistic changes have a significant as age, hormonal status, ethnicity, and sexual behavior, all
impact on women’s urogenital health during this stage, of which undergo significant changes during menopause.
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increasing the incidence of genitourinary symptoms, At this stage, the reduction in Lactobacillus and changes in
recurrent infections, and persistent inflammatory states. urinary microbial balance are linked to an increased risk of
Both the vaginal and urinary microbiomes exert bladder dysbiosis, incontinence, and rUTIs. 28,29 Moreover,
immunomodulatory functions through interactions with antibiotic treatments can disrupt the urinary microbiota,
the mucosal epithelium, resident immune cells, and soluble encouraging the growth of resistant uropathogens and the
mediators such as cytokines, antimicrobial peptides, and formation of biofilms—factors that contribute to persistent
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or recurrent infections. The VM is also closely involved in
immunoglobulins.
rUTIs, as it shares several bacterial species with the urinary
In states of eubiosis, Lactobacillus species predominate in tract. The presence of Lactobacillus in the vagina is crucial
the VM. The acidic environment they produce promotes the for preventing the colonization of pathogens such as E. coli,
expression of antimicrobial peptides such as beta-defensin-2, a major cause of UTIs. In women with vaginal dysbiosis
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which regulates the activation of pattern recognition or low Lactobacillus levels, especially during menopause,
receptors, including Toll-like receptor (TLR) 2 and TLR4, the risk of UTIs increases. In addition, factors such as
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enabling the detection and control of pathogens. 3,11 sexual activity and the use of vaginal douches can facilitate
During postmenopause, the VM becomes less bacterial transfer between the vagina and urinary tract.
dominated by Lactobacillus and richer in anaerobic bacteria Estrogen replacement in postmenopausal women has
characteristic of CST IV, which favors genitourinary been shown to reduce the incidence of UTIs by restoring
infections.⁸ This microbial transition is accompanied by a Lactobacillus levels and promoting a healthy VM, thus
less effective immune response, characterized by increased lowering the risk of rUTIs. 7
levels of inflammatory cytokines such as interleukin Probiotic therapies and the use of L. crispatus
(IL)-1β, IL-6, and tumor necrosis factor (TNF)-α, and suppositories have shown promising potential in
decreased production of defensins and other innate preventing rUTIs, although further research is needed to
antimicrobial molecules. 7,26
confirm their effectiveness.
The urinary microbiome also undergoes dysbiosis.
The gut microbiome is also a key contributor to the
A decline in Lactobacillus in both the vaginal and gut development of UTIs, as bacteria residing in the intestine
microbiota contributes to urinary symptoms such as can translocate to the urinary tract and cause infections.
dysuria, urgency, or recurrent infections. Moreover, this Disruptions in gut microbial composition may influence
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dysbiosis may negatively modulate the activity of resident both the vaginal and urinary microbiota, increasing
immune cells, such as macrophages and dendritic cells, susceptibility to UTIs. Natural defense mechanisms of the
compromising tissue homeostasis and promoting low- intestinal microbiota, such as the production of bacteriocins
grade chronic inflammation. 27
and SCFAs, help limit the growth of uropathogenic bacteria
In summary, menopause leads to the loss of vaginal and and reduce the likelihood of rUTIs. 33
urinary eubiosis, accompanied by an immune imbalance In this context, biotherapeutic strategies, including
that favors chronic inflammatory states and recurrent probiotics and fecal microbiota transplantation, have
pathologies.
demonstrated encouraging outcomes in preventing
7. Vaginal and urinary microbiota in rUTIs by reducing bacterial adhesion, impairing biofilm
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genitourinary infections in menopause development, and enhancing host defenses.
Recurrent UTIs are particularly prevalent in
7.1. Urinary infections postmenopausal women, affecting over half of this
The study by Naji et al. emphasizes the important population and significantly impacting quality of life, as
7
contribution of the intestinal, vaginal, and urinary well as increasing the risk of serious complications such as
microbiomes in the origin and persistence of UTIs, urosepsis. Recent studies using quantitative urine culture
particularly rUTIs in women. Disruptions in these and 16S rRNA gene sequencing in women over 55 years old
microbial communities are thought to facilitate both with rUTIs (some receiving daily antibiotic prophylaxis
the onset and recurrence of such infections. In women and all on vaginal estrogen therapy [ET]) found no major
of reproductive age, the urinary microbiota is mainly differences in the total number of microbial species,
composed of bacteria from the phylum Firmicutes. Its including Lactobacillus.
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Volume 11 Issue 5 (2025) 33 doi: 10.36922/JCTR025150016