Page 36 - JCTR-11-5

Journal of Clinical and
Translational Research Vaginal microbiota in menopause pathologies

vaginosis (BV). Estrogen plays a key role in regulating subject of interest. All publications that did not meet the
1
vaginal pH and stimulates epithelial cells to produce established criteria, as well as studies on the microbiome
glycogen, an essential nutrient for Lactobacillus survival. and conditions unrelated to menopause, were excluded.
The urinary microbiota is also affected by menopause, 3. Vaginal and urinary microbiota in fertile
although its study has been less frequent. Urine in women
healthy women is generally sterile, but with the decrease
in estrogen, the microbiota in the urethra and bladder In healthy, fertile women, estrogen levels and glycogen
change, and the pH is altered. Alterations in the urinary availability directly influence the VM by promoting the
microbiota may facilitate colonization by uropathogenic dominance of Lactobacillus, thickening of the stratified
bacteria, increasing the frequency of recurrent urinary tract squamous vaginal epithelium, and increasing cervical
9,10
infections (UTIs/rUTIs) in postmenopausal women. In mucus secretion. Lactobacillus species are essential
6,7
addition, hormonal changes also affect vaginal hydration in maintaining the vaginal ecosystem, as they produce
and mucus production. These symptoms, including vaginal lactic acid (which lowers vaginal pH), hydrogen peroxide
dryness, irritation, and pain during intercourse, result from (H O ), and bacteriocins—compounds with antimicrobial,
2
2
9
vaginal atrophy caused by estrogen deficiency. Recurrent antiviral, and immunomodulatory properties. They
1,4
genitourinary infections and irritation symptoms can also compete for adhesion sites with other bacteria,
negatively impact the emotional well-being of women, helping to prevent sexually transmitted infections
which is not always addressed in medical studies. This (STIs) and the overgrowth of endogenous opportunistic
suggests that the VM contributes not only to protection microorganisms. 11-14
but also to maintaining vaginal health and the overall Among healthy women of European descent,
1
quality of sexual function. In this context, menopause has Lactobacillus crispatus, Lactobacillus gasseri, and
been associated with changes in the composition, diversity, Lactobacillus jensenii are the predominant H O and
–
2
2
and activity of the microbiota in different body regions— bacteriocin-producing species, while in African American
most notably the vaginal, intestinal, and urinary tracts— women, Lactobacillus iners is most frequently detected.
15
which may influence the general health of postmenopausal Understanding the prevalence of species that colonize
women. The decrease in estrogen levels, along with the the vaginal ecosystem is useful for the development of
8
alteration of the vaginal and urinary microbiota, may products for Lactobacillus replacement therapy. 15
influence a range of health conditions, including urinary This direct effect of estrogen on the quality and increase
incontinence, genital infections, genital discomfort, of Lactobacillus has been demonstrated in reproductive-
gynecological cancer, and periodontal disease. This set of aged women using contraceptives containing estrogen.
5,8
menopause-related diseases constitutes an emerging field According to a review conducted in Australia, contraceptive
of research that has begun to gain attention in recent years. 8
methods that include estrogen may support a favorable
This narrative review seeks to examine the alterations VM in certain groups of women. However, the effects of
in the vaginal and urinary microbiota that occur during progestin-only contraceptives on the vaginal environment
menopause and to identify the related conditions that may remain uncertain, and further research is required to
impact women’s systemic health. Gaining insight into the clarify their potential role in negative reproductive and
underlying causes of these changes could support more sexual health outcomes. 16
effective strategies for managing these disorders. Advances in bacterial gene sequencing, particularly

2. Materials and methods targeting the 16S ribosomal RNA (rRNA) gene, have
enhanced our understanding of the diversity of microbial
This review included the following types of publications: communities in the female genital tract. 2,4,9,15 A study
systematic reviews, narrative reviews, meta-analyses, conducted on asymptomatic women of reproductive
and relevant original studies (cohort studies and case– age in North America, including participants of Asian,
control studies) that demonstrated a low or very low risk White, Black, and Hispanic backgrounds, identified five
of bias and a high or moderate likelihood of establishing distinct types of microbial community structures. Four of
a causal relationship between the vaginal and urinary these were primarily dominated by different Lactobacillus
microbiota and disorders associated with menopause. species: community state (CST) type I (L. crispatus), CST
Articles published from 1990 onwards were included, II (L. gasseri), CST III (L. iners), and CST V (L. jensenii).
provided they were available in the following databases: The fifth type, CST IV, consisted of a more diverse group
PubMed, Elsevier, Science Direct, Wiley, Scopus, Ovid, of bacteria, mostly anaerobic species. It was observed
15
and SciELO, and were directly and explicitly relevant to the that the predominance of lactobacilli in the VM is higher,

Volume 11 Issue 5 (2025) 30 doi: 10.36922/JCTR025150016