Review

Authors: Wallace Jeng Yang Chee, Shu Yih Chew, Leslie Thian Lung Than...

Human vagina is colonised by a diverse array of microorganisms that make up the normal microbiota and mycobiota. Lactobacillus is the most frequently isolated microorganism from the healthy human vagina, this includes Lactobacillus crispatus, Lactobacillus gasseri, Lactobacillus iners, and Lactobacillus jensenii. These vaginal lactobacilli have been touted to prevent invasion of pathogens by keeping their population in check. However, the disruption of vaginal ecosystem contributes to the overgrowth of pathogens which causes complicated vaginal infections such as bacterial vaginosis (BV), sexually transmitted infections (STIs), and vulvovaginal candidiasis (VVC). Predisposing factors such as menses, pregnancy, sexual practice, uncontrolled usage of antibiotics, and vaginal douching can alter the microbial community. Therefore, the composition of vaginal microbiota serves an important role in determining vagina health. Owing to their Generally Recognised as Safe (GRAS) status, lactobacilli have been widely utilised as one of the alternatives besides conventional antimicrobial treatment against vaginal pathogens for the prevention of chronic vaginitis and the restoration of vaginal ecosystem. In addition, the effectiveness of Lactobacillus as prophylaxis has also been well-founded in long-term administration. This review aimed to highlight the beneficial effects of lactobacilli derivatives (i.e. surface-active molecules) with anti-biofilm, antioxidant, pathogen-inhibition, and immunomodulation activities in developing remedies for vaginal infections. We also discuss the current challenges in the implementation of the use of lactobacilli derivatives in promotion of human health. In the current review, we intend to provide insights for the development of lactobacilli derivatives as a complementary or alternative medicine to conventional probiotic therapy in vaginal health.

Topics: Complementary Therapies; Female; Humans; Lactobacillus; Microbiota; Probiotics; Vagina; Vaginosis, Bacterial

PubMed: 33160356
DOI: 10.1186/s12934-020-01464-4

Review

Authors: Linda Abou Chacra, Florence Fenollar, Khoudia Diop...

The vaginal microbiome is a well-defined compartment of the human microbiome. It has unique conditions, characterized by the dominance of one bacterial species, the This microbiota manifests itself by a low degree of diversity and by a strong dynamic of change in its composition under the influence of various exogenous and endogenous factors. The increase in diversity may paradoxically be associated with dysbiosis, such as bacterial vaginosis (BV). BV is the result of a disturbance in the vaginal ecosystem; i.e., a sudden replacement of by anaerobic bacteria such as , and others. It is the most common cause of vaginal discharge in women of childbearing age, approximately 30% of all causes. The etiology of this dysbiosis remains unknown, but its health consequences are significant, including obstetrical complications, increased risk of sexually transmitted infections and urogenital infections. Its diagnosis is based on Amsel's clinical criteria and/or a gram stain based on the Nugent score. While both of these methods have been widely applied worldwide for approximately three decades, Nugent score are still considered the "gold standard" of BV diagnostic tools. Given the limitations of these tools, methods based on molecular biology have been developed as alternative rational strategies for the diagnosis of BV. The treatment of BV aims at restoring the balance of the vaginal flora to stop the proliferation of harmful microorganisms. Prescription of antibiotics such as metronidazole, clindamycin, etc. is recommended. Faced with the considerable uncertainty about the cause of BV, the high rate of recurrence, the unacceptable treatment options, and clinical management which is often insensitive and inconsistent, research on this topic is intensifying. Knowledge of its composition and its associated variations represents the key element in improving the therapeutic management of patients with the most suitable treatments possible.

Topics: Ecosystem; Female; Gardnerella vaginalis; Humans; Lactobacillus; Vagina; Vaginosis, Bacterial

PubMed: 35118003
DOI: 10.3389/fcimb.2021.672429

Review

Authors: Xiaodi Chen, Yune Lu, Tao Chen...

The vaginal microbiome is an intricate and dynamic microecosystem that constantly undergoes fluctuations during the female menstrual cycle and the woman's entire life. A healthy vaginal microbiome is dominated by which produce various antimicrobial compounds. Bacterial vaginosis (BV) is characterized by the loss or sharp decline in the total number of and a corresponding marked increase in the concentration of anaerobic microbes. BV is a highly prevalent disorder of the vaginal microbiota among women of reproductive age globally. BV is confirmed to be associated with adverse gynecologic and obstetric outcomes, such as sexually transmitted infections, pelvic inflammatory disease, and preterm birth. is the most common microorganism identified from BV. It is the predominant microbe in polymicrobial biofilms that could shelter and other BV-associated microbes from adverse host environments. Many efforts have been made to increase our understanding of the vaginal microbiome in health and BV. Thus, improved novel and accurate diagnosis and therapeutic strategies for BV have been developed. This review covers the features of vaginal microbiome, BV, BV-associated diseases, and various strategies of diagnosis and treatment of BV, with an emphasis on recent research progresses.

Topics: Female; Gardnerella vaginalis; Humans; Infant, Newborn; Microbiota; Pregnancy; Premature Birth; Vagina; Vaginosis, Bacterial

PubMed: 33898328
DOI: 10.3389/fcimb.2021.631972

Review

Authors: Makella S Coudray, Purnima Madhivanan

Bacterial vaginosis (BV) affects women of reproductive age and can either be symptomatic or asymptomatic. Approximately 50 % of women are symptomatic and experience vaginal malodor, discharge, itching and increased vaginal pH. BV can increase the risk of contracting many sexually transmitted infections (STIs) such as human immunodeficiency virus (HIV), Neisseria gonorrhea (NG), Chlamydia trachomatis (CT), Trichomonas vaginalis (TV) and herpes simplex virus-2 (HSV-2). Though effective treatment options do exist, metronidazole or clindamycin, these methods have proven not to be effective long term. The purpose of this review is to summarize current literature on the epidemiology of BV and highlight areas of deficiency in current clinical practice with respect to BV. BV recurrence rates are high, approximately 80 % three months after effective treatment. Furthermore, in some instances treatment is ineffective and BV persists. Literature also documents the relationship between BV and human papillomavirus (HPV). HPV is the most common sexually transmitted infection among young adult women while BV is the most common cause of vaginal symptoms among women of reproductive age. BV is associated with high levels of anaerobic organisms which can damage the vaginal epithelium and increase the risk of HPV infection. Recent research also highlights the role of the vaginal microbiome in BV. The results of this review warrant further exploration into the etiology of BV as well as exploration of more long-term effective treatment and the investigation of prognostic indicators. Additionally, the need for a standard definition of recurrent and persistent BV is recognized.

Topics: Female; Humans; Microbiota; Recurrence; Vagina; Vaginosis, Bacterial

PubMed: 31901667
DOI: 10.1016/j.ejogrb.2019.12.035

Review

Authors: Zhaojun Mei, Dandan Li

Probiotics have been widely used in the treatment of intestinal diseases, but the effect of probiotics on female reproductive tract health is still controversial. is the most abundant microorganism in the vagina, which is related to the vaginal mucosal barrier. adheres to the vaginal epithelium and can competitively antagonize the colonization of pathogens. The factors produced by , such as bacteriocin and hydrogen peroxide (HO), can inhibit the growth of pathogenic microorganisms and maintain the low pH environment of the vagina. Probiotics play an important role in maintaining the stability of vaginal microenvironment, improving immune defense and blocking the progression of cervical cancer. We review the research progress of probiotics represented by in gynecological diseases such as human papilloma virus (HPV) infection, bacterial vaginosis (BV) and Genitourinary Syndrome of Menopause (GSM), so as to provide basis for further exerting the role of probiotics in women's health.

Topics: Female; Humans; Hydrogen Peroxide; Lactobacillus; Probiotics; Vagina; Vaginosis, Bacterial

PubMed: 35967876
DOI: 10.3389/fcimb.2022.963868

Review

Authors: Zhongwen Sun, Xinnuo Ge, Bo Qiu...

Vaginal microbiome is mutually beneficial to the host and has a significant impact on health and disease. species, including , are part of the mucosal flora of most healthy women. Under suitable conditions, they can live in the vulvovaginal mucosa, resulting in symptomatic vulvovaginal candidiasis (VVC). Based on the analysis of 16S ribosomal RNA gene sequences, great progress has been made in exploring the composition and structure of vaginal bacterial community. Moreover, researchers have conducted several studies on whether vaginal microbiome will change during VVC infection. In addition, it has been reported that vaginal colonization of probiotics in vaginal microorganisms, especially , can effectively reduce the risk of VVC and treat VVC. This review aims to summarize the changes of vaginal microflora during VVC infection, and further point out the possibility of using lactic acid bacteria as probiotics to treat VVC, so as to reduce the adverse consequences of VVC infection and reduce the expensive treatment cost.

Topics: Female; Humans; Candidiasis, Vulvovaginal; Vagina; Candida albicans; Candida; Probiotics; Antifungal Agents

PubMed: 36816582
DOI: 10.3389/fcimb.2023.1123026

Review

Authors: Namarta Kalia, Jatinder Singh, Manpreet Kaur...

Recurrent vulvovaginal infections (RVVI) has not only become an epidemiological and clinical problem but also include large social and psychological consequences. Understanding the mechanisms of both commensalism and pathogenesis are necessary for the development of efficient diagnosis and treatment strategies for these enigmatic vaginal infections. Through this review, an attempt has been made to analyze vaginal microbiota (VMB) from scratch and to provide an update on its current understanding in relation to health and common RVVI i.e. bacterial vaginosis, vulvovaginal candidiaisis and Trichomoniasis, making the present review first of its kind. For this, potentially relevant studies were retrieved from data sources and critical analysis of the literature was made. Though, culture-independent methods have greatly unfolded the mystery regarding vaginal bacterial microbiome, there are only a few studies regarding the composition and diversity of vaginal mycobiome and different Trichomonas vaginalis strains. This scenario suggests a need of further studies based on comparative genomics of RVVI pathogens to improve our perceptive of RVVI pathogenesis that is still not clear (Fig. 5). Besides this, the review details the rationale for Lactobacilli dominance and changes that occur in healthy VMB throughout a women's life. Moreover, the list of possible agents continues to expand and new species recognised in both health and VVI are updated in this review. The review concludes with the controversies challenging the widely accepted dogma i.e. "VMB dominated with Lactobacilli is healthier than a diverse VMB". These controversies, over the past decade, have complicated the definition of vaginal health and vaginal infections with no definite conclusion. Thus, further studies on newly recognised microbial agents may reveal answers to these controversies. Conversely, VMB of women could be an answer but it is not enough to just look at the microbiology. We have to look at the woman itself, as VMB which is fine for one woman may be troublesome for others. These differences in women's response to the same VMB may be determined by a permutation of behavioural, cultural, genetic and various other anonymous factors, exploration of which may lead to proper definition of vaginal health and disease.

Topics: Biofilms; Candida; Candida albicans; Candidiasis, Vulvovaginal; Coinfection; Female; Gardnerella vaginalis; Host Microbial Interactions; Humans; Lactobacillus; Microbial Interactions; Microbiota; Recurrence; Trichomonas Vaginitis; Trichomonas vaginalis; Vagina; Vaginosis, Bacterial; Virulence Factors

PubMed: 31992328
DOI: 10.1186/s12941-020-0347-4

Review

Authors: Bing Ma, Larry J Forney, Jacques Ravel...

Vaginal microbiota form a mutually beneficial relationship with their host and have a major impact on health and disease. In recent years our understanding of vaginal bacterial community composition and structure has significantly broadened as a result of investigators using cultivation-independent methods based on the analysis of 16S ribosomal RNA (rRNA) gene sequences. In asymptomatic, otherwise healthy women, several kinds of vaginal microbiota exist, the majority often dominated by species of Lactobacillus, while others are composed of a diverse array of anaerobic microorganisms. Bacterial vaginosis is the most common vaginal condition and is vaguely characterized as the disruption of the equilibrium of the normal vaginal microbiota. A better understanding of normal and healthy vaginal ecosystems that is based on their true function and not simply on their composition would help better define health and further improve disease diagnostics as well as the development of more personalized regimens to promote health and treat diseases.

Topics: Biota; Female; Humans; Metagenome; Vagina; Vaginosis, Bacterial

PubMed: 22746335
DOI: 10.1146/annurev-micro-092611-150157

Review

Authors: Lúcia G V Sousa, Sofia A Pereira, Nuno Cerca...

Bacterial vaginosis (BV) is the most common cause of vaginal discharge and is often associated with other health consequences mainly in pregnant women. BV is described by an imbalance in the vaginal microbiota where strictly and facultative anaerobic bacteria outgrow the lactic acid- and hydrogen peroxide-producing Lactobacillus species. The species involved in BV are capable to grow and form a polymicrobial biofilm in the vaginal epithelium. The treatment of BV is usually performed using broad-spectrum antibiotics, including metronidazole and clindamycin. However, these conventional treatments are associated with high recurrence rates. The BV polymicrobial biofilm may have an important role on the treatment outcome and is accounted as one of the factors for treatment failure. Other possible reasons for treatment failure include the presence of species resistant to antibiotics or the chance of reinfection after treatment. Therefore, novel strategies to increase the rates of treatment have been studied namely the use of probiotics and prebiotics, acidifying agents, antiseptics, plant-based products, vaginal microbiota transplantation, and phage endolysins. Although some of them are still in an initial phase of development with very preliminary results, they show great perspectives for application. In this review, we aimed to study the role of the polymicrobial nature of BV in treatment failure and explore a few alternatives for treatment.

Topics: Pregnancy; Female; Humans; Vaginosis, Bacterial; Metronidazole; Vagina; Anti-Bacterial Agents; Biofilms

PubMed: 37042412
DOI: 10.1111/1751-7915.14261

Review

Authors: Myoung Seung Kwon, Heung Kyu Lee

The female reproductive tract harbors a unique microbiome, especially the vagina. The human vaginal microbiome exhibits a low diversity and is dominated by species, compared to the microbiome of other organs. The host and vaginal microbiome mutually coexist in the vaginal microenvironment. Host cells provide glycogen as an energy source, and produce lactic acid, which lowers vaginal pH thereby preventing growth of other bacteria. Bacterial vaginosis can modulate host immune systems, and is frequently associated with various aspects of disease, including sexually transmitted infection, gynecologic cancer, and poor pregnancy outcomes. Because of this, numerous studies focused on the impact of the vaginal microbiome on women`s health and disease. Furthermore, numerous epidemiologic studies also have demonstrated various host factors regulate the vaginal microbiome. The female reproductive tract undergoes constant fluctuations due to hormonal cycle, pregnancy, and other extrinsic factors. Depending on these fluctuations, the vaginal microbiome composition can shift temporally and dynamically. In this review, we highlight the current knowledge of how host factors modulate vaginal microbiome composition and how the vaginal microbiome contributes to maintaining homeostasis or inducing pathogenesis. A better understanding of relationship between host and vaginal microbiome could identify novel targets for diagnosis, prognosis, or treatment of microbiome-related diseases.

Topics: Female; Humans; Lactobacillus; Microbiota; Pregnancy; Sexually Transmitted Diseases; Vagina; Vaginosis, Bacterial

PubMed: 35837395
DOI: 10.3389/fimmu.2022.919728