Vaginal Microbiome: Environmental, Biological, and Racial Influences on Gynecological Health Across the Lifespan

ABSTRACT

The human vaginal microbiome (VMB) is a complex and unique ecosystem composed of various microorganisms, including bacteria, fungi, archaea, viruses, and candidate phyla radiation. A healthy VMB is often characterized by the presence of Lactobacillus species, which play a crucial role in protecting and maintaining homeostasis within the vaginal environment. When this balance is disrupted, the protection of the vaginal epithelium weakens, leading to a reduction in Lactobacillus species and an increased risk of various gynecological and reproductive health issues. However, this generalized description can lead to misconceptions and an incomplete understanding of vaginal health, as Lactobacillus is not always dominant across all ages and racialized groups. Therefore, this review provides a comprehensive analysis of the environmental, biological, and racial influences on the VMB at each stage of a woman's life, highlighting their implications for gynecological health and offering a holistic understanding of the VMB for all women.

1. Defining a Healthy Vaginal Microbiome (VMB)

Much of the literature defines a healthy human VMB as being characterized by a predominant presence of the bacterial species Lactobacillus [1, 2]. Specifically, Lactobacillus crispatus (L. crispatus), Lactobacillus iners (L. iners), Lactobacillus gasseri (L. gasseri), or Lactobacillus jensenii (L. jensenii) [1, 2]. These species maintain vaginal homeostasis by producing metabolites such as lactate, antimicrobials, hydrogen peroxide, and lactic acid; enhancing mucus viscosity; trapping pathogens; and preventing adhesion, growth, and DNA damage to vaginal epithelial cells [1, 2, 3, 4]. However, while this generally applies to women of reproductive age, defining a “healthy vaginal microbiome” solely by the abundance of Lactobacillus provides a generalized and limited description. It excludes considerations for women outside of reproductive age and overlooks variations in vaginal bacterial composition across racialized groups. Additionally, not all Lactobacillus species are associated with a healthy VMB or the maintenance of favorable gynecological and obstetric outcomes [4, 5, 6]. For example, while L. crispatus is consistently linked to low genital inflammation and a reduced risk of adverse outcomes, L. iners is frequently associated with an unstable microbiome [5, 6, 7]. Therefore, acknowledging environmental, biological, and racial influences is essential when defining a healthy VMB to gain a more inclusive understanding.

1.1. Prepubescence to Menarche

While the VMB composition of prepubertal girls has received little empirical attention, most research indicates that during childhood, the VMB is highly diverse, dominated by anaerobes including Bacteroides, Prevotella, Actinomyces, and Fusobacterium, as well as some aerobic bacteria like Staphylococcus aureus and Staphylococcus epidermidis [8, 9, 10]. Similarly, a recent study that performed sequencing analysis of the vaginal flora of healthy preschool girls found that the microbiota was characterized by gram‐negative bacilli such as Pseudomonas, Methylobacterium, and Escherichia [11]. Moreover, the presence of these microorganisms and lack of Lactobacillus contribute to a neutral vaginal pH state during childhood [9, 11, 12].

As menarche approaches, increasing estradiol levels trigger the thickening of the vaginal epithelium and the production of glycogen [13, 14, 15]. Glycogen is broken down by α‐amylase into maltose, maltotriose, and α‐dextrins, which Lactobacillus then metabolizes into lactic acid, creating a more acidic environment [13, 15, 16]. Consequently, during puberty, the VMB becomes increasingly dominated by Lactobacillus, mirroring the bacterial composition of reproductive‐aged women [16, 17]. However, after menarche, the vaginal pH remains higher than what is considered healthy for reproductive‐aged women, indicating that lactobacilli levels do not reach adult counts until later in development [16]. These maturational changes collectively help inhibit the growth of bacteria such as Gardnerella vaginalis and other pathogens associated with the onset of sexual activity [18, 19].

1.2. Reproductive Age

During the reproductive age, Lactobacillus dominates the VMB, and that is crucial for maintaining vaginal health [20, 21, 22]. The presence of lactobacilli is significantly influenced by hormonal changes, with bacterial composition fluctuating in response to estradiol levels during different phases of the menstrual cycle [16, 23, 24]. For instance, during periods of elevated estradiol, such as the follicular, preovulatory, and midluteal phases, glycogen accumulation in the vaginal epithelium promotes lactobacilli colonization, leading to higher lactobacilli counts [23, 25]. Conversely, menstruation is associated with low estradiol levels, decreased lactobacilli concentration, and increased bacterial diversity [23, 25]. Interestingly, these alterations are more pronounced in naturally cycling women compared to those using combined oral contraceptive pills or levonorgestrel intrauterine devices, suggesting that synthetic hormones interfere with the normal variations in the VMB across the menstrual cycle [23, 24].

Another hormone that influences the VMB is cortisol, which may inhibit epithelial maturation and glycogen accumulation, leading to a reduction in Lactobacillus [13, 26]. The impact of psychological stress through HPA axis activation and cortisol production may explain previous findings that African American and Hispanic women have reduced lactobacilli counts and increased levels of other bacterial species, such as Gardnerella, Sneathia, Prevotella, Megasphaera sp., and Prevotella, in comparison to White and Asian women [8, 13, 27, 28, 29]. Lower Lactobacillus dominance among these women compared to White women has also been linked to lower socioeconomic status, education level, and poorer access to healthcare [27, 30, 31]. While the exact reasons for racialized differences in VMB composition remain contested and deserve further exploration, these findings indicate that the impact of race on VMB is likely better explained by a variety of factors rather than by socially constructed racial categories [28, 30, 31, 32].

1.2.1. Pregnancy

During a healthy pregnancy, the placenta generates estradiol and estriol, leading to increased Lactobacillus levels and decreased vaginal pH [33, 34, 35]. The maintenance of a stable lactobacilli population, supported by an acidic pH throughout pregnancy, protects the mother and fetus against infections [36, 37]. Furthermore, the vaginal bacterial composition of pregnant women differs from that of nonpregnant women, with higher levels of Bacteroidales, and Clostridiales found in pregnant samples, while nonpregnant women typically have higher Prevotella, Streptococcus, and Veillonellaceae presence [34, 36, 37]. Nevertheless, this prenatal transition to lower bacterial diversity and higher Lactobacillus levels has been observed to be less pronounced among Black women, potentially due to having higher rates of maternal stress [27, 38].

Following delivery, estradiol levels significantly drop, causing a decrease in lactic acid‐producing bacteria and an increase in other taxa, such as Gardnerella vaginalis and Prevotella bivia, rendering the VMB more vulnerable to pathogens [38, 39, 40]. Such changes arise as early as the onset of labor and persist for up to 1‐year postpartum [34, 40]. Physiological changes during labor and delivery have also been shown to alter vaginal composition postdelivery [34, 41]. For example, elevated levels of heat shock protein 70, as well as hyaluronan, induce changes in the properties of vaginal epithelial cells and immune cells, altering the composition of the vaginal fluid postpartum [34, 42, 43]. Similarly, among a sample of 230 women who required pelvic floor examination postpartum, participants with weakened pelvic floor function showed the highest Lactobacillus depletion 6–8 weeks following delivery, further supporting the impact of physiological changes on the VMB [41].

1.3. Menopause

The onset of menopause is marked by a decline in estrogen levels and is associated with a decrease in Lactobacillus concentration, lower glycogen, and an increase in vaginal pH [8, 12]. Additionally, women typically display high concentrations of anaerobic bacteria such as Gardnerella vaginalis, Candida albicans, and Prevotella spp. at this stage, resulting in a VMB composition comparable to prepubescence [16, 44]. Subsequently, these changes can induce thinning of the vaginal epithelium, leading to symptoms such as vaginal dryness and discomfort [45, 46, 47]. Although this process is natural with vaginal aging, estrogen treatments may be sought to increase hormone production and facilitate glycogen in the VMB, leading to enhanced vaginal mucosa [47, 48]. Conversely, the therapeutic benefit of Lactobacillus during menopause remains contested, as findings on the effects of continued Lactobacillus dominance during this life stage are mixed [46, 47, 48, 49]. Further research is needed to understand why the continued production of estrogens, but not lactobacilli, appears to promote vaginal health after menopause.

Limited data exist on the VMB composition of postmenopausal Black women. However, a recent study found that L. crispatus and L. gasseri dominance were significantly more prevalent in African American postmenopausal women compared to their White age‐matched counterparts, which appears to contradict findings from studies on women of reproductive age [8, 46, 50]. This highlights the need for a deeper exploration into the parameters of a healthy microbiome specifically tailored to both racial and age‐related differences (Figure 1).

FIGURE 1.

During (A) prepubescence to menarche, the absence of estradiol results in a neutral vaginal pH dominated by anaerobic bacteria, with no presence of Lactobacillus. As women transition into (B) reproductive age, hormonal fluctuations, particularly estradiol, drive significant changes in bacterial diversity. Throughout (C) the menstrual cycle, low estradiol levels increase bacterial diversity and reduce Lactobacillus, while rising estradiol levels promote Lactobacillus dominance. (D) Racial variations also influence the vaginal microbiota, with distinct differences in composition observed among White, Asian, African American, and Hispanic women. (E) Pregnancy introduces further changes, as elevated estradiol and estriol levels increase Lactobacillus to protect both the mother and fetus. However, the drop in estrogen levels postpartum leads to a reduction in Lactobacillus and a rise in other microbial taxa. During (F) menopause, reduced estrogen levels lead to decreased glycogen, thinning of the vaginal epithelium, and a decline in Lactobacillus, while species such as Candida albicans, Prevotella, and Gardnerella become more prominent. Created in BioRender.Dubé‐Zinatelli, E. (2024)

2. Gynecological Conditions Across the Lifespan

There are numerous gynecological conditions that arise throughout a woman's life [9, 27, 48]. While many conditions predominantly affect women of reproductive age due to environmental and physical factors that increase susceptibility during this period, vaginal health is a concern for women of all ages [12, 21]. Understanding the conditions that affect women at specific stages of life is essential for comprehensive gynecological care [49, 51]. However, research on the VMB remains underdeveloped, with many discrepancies in the literature and a lack of clear definitions for specific conditions. Therefore, the following section aims to clarify these terms and provide a comprehensive understanding of the most common gynecological conditions affecting women at different life stages and their implications for health and well‐being.

2.1. Vaginal Dysibosis

With the rise in microbiome research, the term “dysbiosis” has become well‐established, referring to imbalances in resident microbial communities in the gut that are associated with adverse human health and disease states [52, 53]. While gut dysbiosis remains the most commonly studied type of dysbiosis, advancements in VMB research have introduced the concept of “vaginal dysbiosis” (VD). This term describes a disruption in the microbial balance of the vagina, characterized by a decrease in protective Lactobacillus species, which weakens the vaginal epithelium's defense and allows for pathogenic growth [3, 54].

VD is not an actual illness but rather refers to an imbalance in the VMB. However, this imbalance can lead to gynecological infections such as human papillomavirus (HPV), herpes, and human immunodeficiency virus (HIV) [3]. Conversely, these gynecological infections can also lead to a state of VD, creating a cyclical relationship where each can cause the other [3]. Additionally, much of the literature often uses VD interchangeably with bacterial vaginosis (BV), a gynecological condition characterized by a polymicrobial imbalance. Some researchers use the term VD more broadly to refer to any vaginal condition caused by a decreased prevalence of Lactobacillus, which includes conditions like atrophic vaginitis that are not caused by pathogens or infections [7]. Other papers define VD as encompassing all conditions that result in an altered composition of vaginal microbiota, including bacteria, viruses, and fungi. Consequently, conditions such as desquamative inflammatory vaginitis, vaginal candidiasis, and trichomoniasis are also considered types of VD [55].

Nevertheless, in almost all cases, VD typically includes only gynecological conditions that occur after puberty, as it is almost always linked to Lactobacillus. The issue with this definition is that the predominance of Lactobacillus within the VMB does not always indicate a healthy state, nor does its absence always signify dysbiosis. This is evident before puberty and in some racialized groups [9, 38]. Therefore, defining VD solely by the absence of lactobacilli is inadequate for an inclusive understanding of women's health [56, 57, 58, 59].

2.2. Vaginitis

The term “vaginitis,” sometimes referred to as vulvovaginitis, is commonly used in clinical settings by both patients and healthcare providers as a diagnostic term [60]. While much of the literature highlights vaginitis as a prevalent gynecological issue affecting women of all ages, it is important to understand that vaginitis is a nonspecific term encompassing a broad range of conditions that cause vulvovaginal symptoms [60]. These symptoms include abnormal vaginal discharge, odor, irritation, itching, or burning [61, 62]. Furthermore, vaginitis can be a symptom of various gynecological issues, including infectious conditions such as vulvovaginal candidiasis (VVC) and trichomoniasis, as well as noninfectious vulvar disorders like vaginal atrophy [60] (Table 1).

TABLE 1.

Gynecological conditions across the lifespan.

Gynecological risk factors	Common conditions	Symptoms	Treatment
Prepubescence Anatomical factors (underdeveloped labia minora and majora) Physiological factors (low vaginal pH) Behavioral factors (hygiene practices like nose‐picking, thumb‐sucking) All leading to the intrusion of pathogenic microorganisms	Nonspecific vulvovaginitis	Inflammation of the vulvar and vaginal regions.	Educating and improving vulvar hygiene (e.g., teaching proper wiping techniques, avoiding tight or irritating clothing) Sitz baths to soothe symptoms and clean the area without using soap or washcloth
	Lichen sclerosis (inflammatory skin condition)	Pain, pruritus, and a burning sensation along the perineal region.	High‐dose topical steroids with gradual transition to lower‐potency steroids
	Pinworms (infection)	Usually asymptomatic, but can include itching of the anal or vaginal area, especially at night, vaginal discharge, and insomnia.	Antiparasitic such as pyrantel pamoate
Reproductive age Variations in innate and adaptive immune systems Increased sexual activity and partners Shifts in estrogen Antibiotic use Psychosocial stress Racial and ethnic differences	Bacterial vaginosis	Unusual vaginal discharge, odor, itching, and burning sensations.	Antibiotics such as metronidazole and clindamycin
	Trichomoniasis (sexually transmitted infection)	Vaginal discharge (often yellow or green), painful intercourse, urinary tract infection symptoms, vaginal itching, and pelvic pain.	Antibiotics such as metronidazole and clindamycin
	Vulvovaginal candidiasis (fungal infection)	Vulvar and vaginal erythema, excoriations, thick white adherent discharge, vaginal itching, burning, pain and redness and swelling.	Antifungals such as fluconazole
Menopause Drop in estradiol Rise in vaginal pH Loss of lactobacilli Overgrowth of pathogenic bacteria	Vulvovaginal atrophy	Vaginal dryness, decreased lubrication, pruritus, soreness, stinging pain in the vaginal and vulvar areas, vaginal spotting, thin yellow or grey watery discharge, increased urinary frequency, urgency, and incontinence.	Hormone replacement therapy (HRT)

2.2.1. Prepubescence

“Vulvovaginitis” is typically used to refer to the most common gynecological condition affecting prepubescent girls. Many studies simply refer to it as vulvovaginitis, but it is also known as prepubertal vulvovaginitis or nonspecific vulvovaginitis [63, 64]. Nonspecific vulvovaginitis accounts for 61.8% of the gynecological problems observed in children and adolescents [63, 65]. In pediatric patients, around 70%–80% of cases of vulvovaginitis have nonspecific causes and are defined quite broadly by inflammation of the vulvar and vaginal regions [9, 11, 63].

This condition is generally associated with anatomical, physiological, and behavioral factors linked to prepubescence leading to the intrusion of pathogenic microorganisms [9, 66]. Prepubertal females exhibit an underdeveloped labia minora and a labia majora with minimal adipose tissue and a lack of pubic hair, increasing the susceptibility of the vagina to bacterial intrusion from the anus and a higher risk of irritation [67]. Moreover, the absence of estrogen production during this phase results in an alkaline vaginal pH and decreased protective lactobacilli concentration, creating an environment conducive to the overgrowth of fecal or oropharyngeal bacteria [68]. Lastly, young girls often exhibit less‐than‐optimal hygiene practices such as nose‐picking, thumb‐sucking, or scratching, coupled with inadequate handwashing, which facilitates the transfer of oropharyngeal and skin bacteria to the vaginal area, increasing their vulnerability to vulvovaginitis [66, 67].

Prepubescent vulvovaginitis is complex due to the controversial nature of what constitutes normal vaginal flora at this age [51, 69, 70]. This uncertainty makes it difficult to identify the presence of pathogens, determine the causes, and select the appropriate treatment [70]. However, in cases of prepubescent vulvovaginitis where foreign bodies or sexually transmitted infections (STIs) are found, the possibility of sexual abuse must be considered, and appropriate measures are subsequently taken [21, 71, 72].

The causes of vulvovaginitis in prepubertal patients differ from those in pubertal patients. A study comparing vaginal samples from prepubertal and pubertal girls found that prepubertal girls predominantly had gram‐positive cocci and Enterobacteriaceae, while VVC and BV were more commonly detected in adolescents [72]. These differences are due to lactobacilli starting to populate the vagina with the onset of estrogen production during puberty, which explains why estrogen‐dependent Candida species are quite unusual before puberty [72]. Additionally, the higher rate of sexual activity during adolescence contributes to the prevalence of BV and Candida infections compared to childhood [73]. In some cases, Candida may occur in infants and toddlers still in diapers or in patients with predisposing risk factors such as recent antibiotic use, underlying immunosuppression, or a diagnosis of diabetes [70, 73].

Given that the vaginal microbiology present during childhood is different from that of adulthood, using the typical treatments for adult vaginitis has been shown to be ineffective and exacerbate symptoms in children [9, 11, 74]. Currently, when the causes of the condition are known, most treatments revolve around educating and improving vulvar hygiene, such as teaching children to wipe front to back and avoiding tight or irritating clothing. Sitz baths are also recommended to soothe symptoms and help keep the area clean without using soaps or washcloths [67, 74]. In cases where pathogens are present, such as pinworms, antiparasitics are used for treatment [67]. For inflammatory skin conditions like lichen sclerosis, high‐dose topical steroids are initially used, with a gradual transition to lower‐potency steroids for maintenance [70, 73]. Taken together, vulvovaginitis, particularly nonspecific vulvovaginitis, is most common among prepubescent girls, with most of the causes remaining unknown. This lack of understanding complicates treatment and highlights the need for more research on the VMB of girls at this age. Improving knowledge of the VMB and the mechanism behind these conditions is crucial for better prevention and treatment, as gynecological health during childhood may have lasting effects into adulthood.

2.2.2. Reproductive Age

Infectious vaginitis is most common in women of reproductive age [75]. The primary causes are BV, VVC, and trichomoniasis [76]. VVC, a fungal infection caused mostly by the polymorphic opportunistic fungus Candida albicans, affects 70%–75% of women over their lifetimes in the United States [77, 78, 79]. Typical clinical features include vulvar and vaginal erythema, excoriations, thick white adherent discharge, vaginal itching, burning, pain, and redness and swelling [77, 80, 81]. Candida are asymptomatic species that are part of the VMB of reproductive age women and can later develop pathogenicity [79, 80, 81]. Trichomoniasis, one of the most prevalent nonviral STIs in the United States, is caused by the protozoan Trichomonas vaginalis [82]. Although it affects both women and men, 89% of trichomoniasis patients are women [82]. In women, clinical features include vaginal discharge (often yellow or green), painful intercourse, urinary tract infection symptoms, vaginal itching, and pelvic pain [83, 84]. BV is the most common condition of the lower genital tract, affecting approximately 30% of females of reproductive age. It is characterized by a decrease in Lactobacillus species, leading to a shift from Lactobacillus dominance to an increased abundance of anaerobic species such as Gardnerella, Leptotrichia, Prevotella, and facultative bacteria [3, 29]. Symptoms of BV include unusual vaginal discharge, odor, itching, and burning sensations [29, 85, 86].

While each of these conditions has unique characteristics, they will be grouped together to provide a general overview of how they affect women during the reproductive period. Generally, all three conditions arise from disruptions in the balance of the vaginal microbiota, weakening the protection of the vaginal epithelium and allowing for a shift in microbial communities [3]. Consequently, protective Lactobacillus species are replaced by pathogenic microorganisms, leading to various gynecological and reproductive health issues [2, 3, 40, 57, 87]. Multiple factors can lead to these conditions, most of which are linked to endogenous and exogenous changes during the reproductive period, such as shifts in estrogen levels, increased sexual activity and partners, and pregnancy [20]. Other causes include differences in gene polymorphisms, variations in the innate and adaptive immune systems, the composition and quantity of vaginal secretions, and epithelial cell surface ligands, allergies, antibiotic use, serum glucose levels, and psychosocial stress [4, 29, 79–81]. For VVC, the antifungal fluconazole is the first‐line treatment [78]. BV and trichomoniasis are often treated with oral antibiotics such as metronidazole and clindamycin [81, 88–90].

Importantly, sexual practices contribute to the development of all three conditions, with increased sexual partners increasing susceptibility [91, 92]. Additionally, male sexual partners of women with these conditions can affect recurrence rates by being asymptomatic and unknowingly spreading the infection [93, 94, 95]. As a result, treating asymptomatic male partners can enhance women's cure rates for trichomoniasis [81]. Conversely, in the case of BV, treating male sexual partners with oral metronidazole has shown no effect on recurrence in the female [96]. For acute VVC, treatment is not recommended for asymptomatic sexual partners or women who are asymptomatic [93].

During reproductive age, these conditions are most prevalent and have been shown to pose significant obstetric issues affecting both mother and fetus, such as increased maternal and fetal/infant morbidity, amniotic fluid infection, preterm labor, and premature birth [29, 87, 97–99]. A common problem with the standard antibiotic treatment is the risk of antibiotic resistance and health risks they pose for the developing fetus during pregnancy [100, 101, 102]. Interestingly, probiotic treatments for vaginal infections have recently emerged as promising alternatives to avoid antibiotic resistance and harm to the fetus. These treatments work by restoring protective Lactobacillus to the VMB [103, 104, 105].

Racial and ethnic differences significantly impact the risk of acquiring vaginal infections [91, 106, 107]. For example, African American women report symptoms more frequently and with higher incidence than White women [106]. African American women also have a higher risk of contracting BV compared to White or Asian American women, with prevalence rates among African American women being twice as high as that of White women [8, 86, 108]. Moreover, Trichomonas vaginalis disproportionately affects Black women [91, 94]. Reasons for these variations may include racial differences in bacterial composition, which affect susceptibility to gynecological infections [8, 86]. However, more research is needed to understand these implications since factors such as access to healthcare, lower socioeconomic status, and higher levels of stress in racialized women have also been seen to contribute to increased gynecological infections in Black women [28, 30, 31, 32, 107].

2.2.3. Menopause

There are also gynecological conditions leading to vaginitis that do not involve infections. One such condition is atrophic vaginitis, also known as vulvovaginal atrophy (VVA), which affects menopausal women. VVA, often defined as a collection of symptoms associated with vaginal dryness, is a common condition that affects 50%–60% of postmenopausal females [46, 109]. VVA occurrence has been linked to estradiol levels dropping during menopause, which induces physiological and structural changes within the vulvovaginal mucosa [22, 110].

Prior to menopause, estrogens induce the proliferation of the vaginal epithelium wall layers, resulting in smooth muscle fibers, collagen maintaining moist and thick vaginal epithelium, and the presence of rugae [46, 111]. However, declining levels of estrogens during menopause can lead to the thinning of the vaginal epithelium, less exfoliation of cells into the vagina, and a rise of vaginal pH between 5 and 7.5, ultimately resulting in a loss of lactobacilli and an overgrowth of pathogenic bacteria such as staphylococci, group B streptococci, and coliforms [110, 112].

After menopause, a reduction in the elasticity of the vagina, an increase in connective tissue, a decrease in vaginal blood flow, and a decrease in vaginal lubrication are all common symptoms but can also be associated with early stages of VVA [46, 110, 112]. As VVA persists, vaginal dryness occurs, and thinning of the epithelial lining leads to pruritus, soreness, and stinging pain in the vaginal and vulvar areas [111]. Vaginal spotting, due to small tears in the vaginal epithelium, may also occur, as well as some thin yellow or grey watery discharge from the rise of pH [109]. Urinary symptoms associated with VVA include increased frequency, urgency, and incontinence [111]. Due to minimal changes in the vaginal mucosa, clinical manifestations of VVA are reported in only 4% of women during the first few years following menopause [109]. As estrogen deficiency grows, dystrophic and atrophic changes develop in the vaginal mucosa, vulva, and structures of the urogenital tract, where atrophic changes are observed in almost 50% of women 7–10 years after the end of menstruation, eventually affecting 73%–75% of women [22, 109]. Given the association between estrogen depletion, reduction in Lactobacillus in the VMB, and subsequent VVA, it is unclear why some research has found that postmenopausal women continue to have stable lactobacilli presence in the absence of natural hormones, although the absence of the menstrual cycle may play a supporting role in VMB stability [46, 50]. Given the potential influence of birth control and other synthetic hormones on the VMB [36, 37], future research must control for hormone replacement therapy (HRT) use among postmenopausal women in order to make this relationship clearer.

Standard treatment for VVA often consists of HRT, as the administration of estrogens locally or orally can help improve glycogen production and Lactobacillus abundance in the VMB [47, 48, 113]. However, the need for nonhormonal treatments is dire, given that antiestrogens are used as a preventative treatment in breast cancer survivors, and these treatments often result in or exacerbate VVA symptoms [114, 115, 116]. A comprehensive overview of VVA therapeutics and the impact of reproductive cancers is outside of the scope of this paper, although several recent nonhormonal treatments have shown promise [115, 116, 117].

3. Conclusion

The VMB, with its primary domination of Lactobacillus species during reproductive age, plays a pivotal role in preserving vaginal health and protecting against infections. While a Lactobacillus dominant vaginal environment is commonly associated with a healthy microbiome, it is essential to recognize that Lactobacillus dominance as a universal indicator of vaginal health does not account for differences observed across age, racialized groups, and hormonal fluctuation. Very little research has focused on the VMB of women outside of reproductive age, making it difficult to draw conclusions on distinct bacterial changes. Given the observed racial differences in VMB composition among reproductive‐aged women, it would be interesting to investigate whether these differences are present before puberty.

Evidence suggests considerable variation in the VMB throughout the lifespan, implying that gynecological consequences will manifest differently across each developmental phase. Thus, it is crucial to understand how environmental, biological, and racial influences affect the VMB at each stage and their implications for health and well‐being.

Ethics Statement

The authors confirm that the ethical policies of the journal, as noted on the journal's author guidelines page, have been adhered to. No ethical approval was required as this is a review article with no original research data.

Conflicts of Interest

The authors declare no conflicts of interest.

Data Availability Statement

The data that support the findings of this study are available from the corresponding author upon reasonable request. The data are not publicly available due to privacy or ethical restrictions.