Cervicovaginal microbiota, women's health, and reproductive outcomes

The Vaginal Microbiota Composition and Genital Infections during and after Pregnancy among Women in Pemba Island, Tanzania

We investigated the vaginal microbiota (VMB) composition, prevalence of genital pathogens and their association among pregnant and post-delivery women in Pemba Island, Tanzania. Vaginal swabs were collected from 90 women, at two time points during pregnancy (<20 weeks of gestational age [GA] and ≥20 weeks GA) and once after delivery, when possible. IS-pro assay was used for VMB characterization. Chlamydia trachomatis (CT), Neisseria gonorrhea (NG), Trichomonas vaginalis (TV), Mycoplasma genitalium (MG) and human papillomavirus (HPV) were detected by qPCRs. VMB were mostly Lactobacillus dominant during pregnancy and non-Lactobacillus dominant post-delivery. A significant decrease in VMB richness was observed during pregnancy among paired and unpaired samples. Shannon diversity was significantly lower during pregnancy than post-delivery among unpaired samples. Klebsiella species and Streptococcus anginosus were the most commonly identified pathobionts at all timepoints. A high abundance of pathobionts was mostly seen in women with non-Lactobacillus dominant VMB. At ≥20 weeks GA timepoint during pregnancy, 63.0% of the women carrying one or more genital pathogen (either HPV, CT, TV, or MG) had L. iners dominant VMB. NG was not detected pre-delivery. This study contributes evidence on VMB composition, its changes during pregnancy and post-delivery, and their association with pathobionts and genital pathogens.

Physiological Changes and Interactions Between Microbiome and the Host During Pregnancy

In recent years, it has become clear that microbiome play a variety of essential roles in human metabolism, immunity, and overall health and that the composition of these microbiome is influenced by our environment, diet, weight, hormones, and other factors. Indeed, numerous physiological and pathological conditions, including obesity and metabolic syndrome, are associated with changes in our microbiome, referred to as dysbiosis. As a result, it is not surprising that such changes occur during pregnancy, which includes substantial weight gain and significant changes in metabolism and immune defenses. The present review relates physiological changes during pregnancy to alterations in the microbial composition at various sites, including the gut, oral cavity, and vagina. Pregnancy has been linked to such microbial changes, and we believe that, in contrast to certain disease states, these microbial changes are vital for a healthy pregnancy, probably through their influence on the mother’s immunological, endocrinological, and metabolic status.

The negative impact of most relevant infections on fertility and assisted reproduction technology

Infections may act with variable impact on the physiopathology of the reproductive organs, determining infertility or reducing the outcomes of assisted reproduction technology. The aim of this narrative review is to describe the existing evidence regarding the pathogens with a supposed or recognized role in reproductive medicine. Viral hepatitis, as well as HIV, can reduce sperm quality. Syphilis carries a risk of erectile dysfunction and increased endometrial thickness. Chlamydia is the main cause of pelvic inflammatory disease. In relation to Mycoplasma and Ureaplasma spp., only few species seem to show a correlation with infertility and poor in-vitro fertilization outcomes. There is evidence of a role for bacterial vaginosis in early pregnancy loss. HPV infection in males seems to determine infertility. Herpesviruses are more a risk for fetuses than for fertility itself. Zika virus is responsible for altered early embryo development and waiting to conceive is recommended in suspected or confirmed cases. The impact of SARS-CoV-2 is yet to be elucidated. Rubella and toxoplasmosis can provoke important congenital defects and therefore screening is mandatory before conception; a vaccine for Rubella is recommended. Further and well-designed studies are still needed to better elucidate the role of some infectious agents, to improve fertility and its treatments.

Preliminary Identification of the Aerobic Cervicovaginal Microbiota in Mexican Women With Cervical Cancer as the First Step Towards Metagenomic Studies

Cervical cancer (CC) is considered a public health problem. Recent studies have evaluated the possible relationship between the cervicovaginal microbiome and gynecologic cancer but have not studied the relationship between aerobic bacterial communities and neoplasia. The study aimed to identify the cultivable aerobic bacterial microbiota in women with cervical cancer as a preliminary approach to the metagenomic study of the cervicovaginal microbiome associated with cervical cancer in Mexican women. An observational cross-sectional study was conducted, including 120 women aged 21-71 years, divided into two study groups, women with locally advanced CC (n=60) and women without CC (n=60). Sociodemographic, gynecological-obstetric, sexual, and habit data were collected. Cervicovaginal samples were collected by swabbing, from which standard microbiological methods obtained culturable bacteria. The strains were genetically characterized by PCR-RFLP of the 16S rRNA gene and subsequently identified by sequencing the same gene. Variables regularly reported as risk factors for the disease were found in women with CC. Differences were found in the prevalence and number of species isolated in each study group. Bacteria commonly reported in women with aerobic vaginitis were identified. There were 12 species in women with CC, mainly Corynebacterium spp. and Staphylococcus spp.; we found 13 bacterial species in the group without cancer, mainly Enterococcus spp. and Escherichia spp. The advanced stages presented a more significant number of isolates and species. This study provided a preliminary test for cervicovaginal metagenomic analysis, demonstrating the presence of aerobic cervicovaginal dysbiosis in women with CC and the need for more in-depth studies.

Influence of Maternal Microbiome and Inflammatory Response in Preterm Birth: Recent Aspects of the Prevention of Preterm Birth

Preterm birth (PTB) is a global health issue and one of the most challenging problems affecting 12.9 million births worldwide. PTB is a multi-etiological disease and remains incompletely understood. The major cause of PTB is infection or inflammation and disruption of the vaginal microbiome, which affects the maternal immunologic response leading to PTB. The vaginal microbiome composition changes by a shift in the community are typically dominated by Lactobacillus during pregnancy. There are complex interactions between the maternal microbiome in pregnancy and the development of PTB, therefore, researchers have struggled to connect the maternal microbiome with the dysregulation of the maternal immune response in cases of PTB. The host microbiome affects alterations of the microorganisms with external stimuli such as disease, nutrition, immunity, and behavior. In this review, we discuss the complex association between the maternal microbiome and the risk of PTB and also focus on recent aspects of the prevention of PTB.

Effects of group B streptococcus infection on vaginal micro-ecology and pregnancy outcomes of pregnant women in late pregnancy

BACKGROUND

Invasive infection with group B streptococcus (GBS) can lead to intrauterine infection, and GBS can also spread via vertical transmission between mother and infant, resulting in adverse pregnancy outcomes. This study aimed to investigate the effects of GBS colonization in late gestation on vaginal micro-ecology, pregnancy outcomes and neonatal outcome.

METHODS

One hundred and twenty pregnant women in the third trimester infected with GBS and 120 healthy counterparts who underwent a prenatal examination in the obstetrics department of the study hospital from June 2019 to December 2020 were selected for inclusion in the study. Vaginal micro-ecological index, mode of delivery, adverse pregnancy outcomes and neonatal Apgar score were compared between the two groups.

RESULTS

The incidence rates of vaginal micro-ecological disorders, intrauterine infection and neonatal infection were significantly higher in the GBS group compared with the control group. The incidence rates of neonatal fetal distress and pathological jaundice were much higher in the GBS group compared with the control group. The neonatal Apgar score was markedly lower in the GBS group compared with the control group.

CONCLUSIONS

GBS infection is correlated with the vaginal micro-environment. GBS colonization in late pregnancy has adverse effects on vaginal micro-ecology and pregnancy outcome.

Distribution of ermB, ermF, tet(W), and tet(M) Resistance Genes in the Vaginal Ecosystem of Women during Pregnancy and Puerperium

The inhabitants of the vaginal ecosystem can harbor genetic determinants conferring antimicrobial resistance. However, detailed data about the distribution of resistance genes in the vaginal microbiome of pregnant women are still lacking. Therefore, we assessed the presence of macrolide (i.e., erm genes) and tetracycline (i.e., tet genes) resistance markers in the vaginal environment of Caucasian women at different gestational ages. Furthermore, the detection of resistance genes was related to the composition of the vaginal microbiota. A total of 228 vaginal samples, collected at different trimesters of pregnancy or during the puerperium, were tested for the presence of ermB, ermF, tet(W), and tet(M) by in-house end-point PCR assays. The composition of the vaginal microbiota was assessed through a microscopic evaluation (i.e., Nugent score) and by means of sequencing V3–V4 hypervariable regions of the bacterial 16 rRNA gene. Overall, the most detected resistance gene was tet(M) (76.7%), followed by ermB (55.2%). In 17% of women, mainly with a ‘normal’ vaginal microbiota, no resistance genes were found. Except for tet(W), a significant correlation between the positivity of resistance genes and a dysbiotic vaginal status (i.e., bacterial vaginosis (BV)) was noticed. Indeed, samples positive for at least one resistance determinant were characterized by a decrease in Lactobacillus spp. and an increase of BV-related genera (Prevotella, Gardnerella, Atopobium, Sneathia). A high predominance of vaginal Lactobacillus spp. (>85%) was associated with a lower risk of tet(W) gene detection, whereas the presence of Megasphaera (>1%) increased the risk of positivity for all analyzed genes. Different types of vaginal microbiota are associated with peculiar resistance profiles, being a lactobacilli-dominated ecosystem poor in or free of resistance genes. These data could open new perspectives for promoting maternal and neonatal health.

A non-optimal cervicovaginal microbiota in pregnancy is associated with a distinct metabolomic signature among non-Hispanic Black individuals

Biomechanical and molecular processes of premature cervical remodeling preceding spontaneous preterm birth (sPTB) likely result from interactions between the cervicovaginal microbiota and host immune responses. A non-optimal cervicovaginal microbiota confers increased risk of sPTB. The cervicovaginal space is metabolically active in pregancy; microbiota can produce, modify, and degrade metabolites within this ecosystem. We establish that cervicovaginal metabolomic output clusters by microbial community in pregnancy among Black individuals, revealing increased metabolism within the amino acid and dipeptide pathways as hallmarks of a non-optimal microbiota. Few differences were detected in metabolomic profiles when stratified by birth outcome. The study raises the possibility that metabolites could distinguish women with greater risk of sPTB among those with similar cervicovaginal microbiota, and that metabolites within the amino acid and carbohydrate pathways may play a role in this distinction.

Lactobacillus spp. create a protective micro-ecological environment through regulating the core fucosylation of vaginal epithelial cells against cervical cancer

Vaginal dysbiosis often occurs in patients with cervical cancer. The fucosylation of mucosal epithelial cells is closely related to microbial colonization, and play an important role in protecting the vaginal mucosal epithelial cells. However, no reports on the relationship between vaginal dysbiosis and abnormal mucosal epithelial cell fucosylation, and their roles in the occurrence and development of cervical cancer are unavailable. Here we report that core fucosylation levels were significantly lower in the serum, exfoliated cervical cells and tumor tissue of cervical cancer patients. Core fucosyltransferase gene (Fut8) knockout promoted the proliferation and migration of cervical cancer cells. In patients with cervical cancer, the vaginal dysbiosis, and the abundance of Lactobacillus, especially L. iners, was significantly reduced. Meanwhile, the abundance of L.iners was positively correlated with core fucosylation levels. The L. iners metabolite lactate can activate the Wnt pathway through the lactate-Gpr81 complex, which increases the level of core fucosylation in epidermal cells, inhibiting the proliferation and migration of cervical cancer cells, and have application prospects in regulating the vaginal microecology and preventing cervical cancer.

Vaginal Microbiota: Age Dynamic and Ethnic Particularities of Algerian Women

The composition of the vaginal microbiota is a key element for maintaining gynecological and reproductive health. With the aim of obtaining an accurate overview of the vaginal microbiota of Algerian women, in terms of their age and ethnic group, we conducted a 16S rRNA gene targeted metagenomic analysis of 100 vaginal samples taken from healthy childbearing and menopausal women. These data were used to establish the pattern of the vaginal microbiota during reproductive and postreproductive phases. Hormone levels were correlated to changes in microbial composition for menopausal women. The ethnic comparison revealed a particular microbiota profile for Algerian women, with a dominance of CST III and CST I. A rapid qPCR method developed by the authors was successfully used to identify the vaginal bacterial pattern for a customized gynecological management.

The role of gut and genital microbiota and the estrobolome in endometriosis, infertility and chronic pelvic pain

BACKGROUND

Endometriosis is a chronic, burdensome condition that is historically understudied. Consequently, there is a lack of understanding of the etiology of the disease and its associated symptoms, including infertility and chronic pelvic pain (CPP). Endometriosis development is influenced by estrogen metabolism and inflammation, which are modulated by several factors including the microbiome and the estrobolome (the collection of genes encoding estrogen-metabolizing enzymes in the gut microbiome). Therefore, there is increasing interest in understanding the role of microbiota in endometriosis etiology.

OBJECTIVE AND RATIONALE

To date, there is no cure for endometriosis and treatment options often are ineffective. This manuscript will review the potential relationship between the microbiome and endometriosis, infertility and CPP and highlight the available data on the microbiome in relation to endometriosis and its related symptoms. The overarching goal of this manuscript is to inform future microbiome research that will lead to a deeper understanding of the etiology of the disease and possible diagnostic modalities and treatments. The potential impact of the microbiome on estrogen regulation modulated by the estrobolome, as well as inflammation and other endometriosis-promoting mechanisms within the genital tract, will be reviewed. The methodological limitations of microbiome-related studies will be critically assessed to provide improved guidelines for future microbiome and clinical studies.

SEARCH METHODS

PubMed databases were searched using the following keywords: endometriosis AND microbiome, infertility AND microbiome, pelvic pain AND microbiome, IVF (in-vitro fertilization) AND microbiome, endometriosis AND infertility. Clinical and preclinical animal trials that were eligible for review, and related to microbiome and endometriosis, infertility or CPP were included. All available manuscripts were published in 2002-2021.

OUTCOMES

In total, 28 clinical and 6 animal studies were included in the review. In both human and animal studies, bacteria were enriched in endometriosis groups, although there was no clear consensus on specific microbiota compositions that were associated with endometriosis, and no studies included infertility or CPP with endometriosis. However, bacterial vaginosis-associated bacteria and Lactobacillus depletion in the cervicovaginal microbiome were associated with endometriosis and infertility in the majority (23/28) of studies. Interpretation of endometrial studies is limited owing to a variety of methodological factors, discussed in this review. In addition, metadata outlining antibiotic usage, age, race/ethnicity, menopausal status and timing of sample collection in relation to diagnosis of endometriosis was not consistently reported. Animal studies (6/6) support a bidirectional relationship between the gut microbiota and endometriosis onset and progression.

WIDER IMPLICATIONS

There is evidence that a dysbiotic gut or genital microbiota is associated with multiple gynecologic conditions, with mounting data supporting an association between the microbiome and endometriosis and infertility. These microbiomes likely play a role in the gut-brain axis, which further supports a putative association with the spectrum of symptoms associated with endometriosis, including infertility and CPP. Collectively, this review highlights the demand for more rigorous and transparent methodology and controls, consistency across the field, and inclusion of key demographic and clinical characteristics of disease and comparison participants. Rigorous study designs will allow for a better understanding of the potential role of the microbiome in endometriosis etiology and the relationship to other disorders of the female reproductive tract.

Assessment of vaginal and endometrial microbiota by real-time PCR in women with unexplained infertility

AIM

Microbiota of the reproductive tract may be associated with unexplained infertility in women. We aimed to determine the derangements of vaginal and endometrial microbiota related to unexplained infertility by real-time polymerase chain reaction (real-time PCR) microbiota analyses of vaginal and endometrial samples of the unexplained infertility patients and fertile women.

MATERIALS AND METHODS

Twenty-six women with unexplained infertility and 26 age-matched fertile women were included. Vaginal and endometrial samples were obtained in the mid-menstrual cycle for analysis by quantitative real-time PCR method.

RESULTS

The proportion of lactobacilli-impaired microbiota was significantly higher in the vaginal samples of unexplained infertility patients (76.9% vs. 26.9%; p < 0.001). Those with impaired lactobacilli microbiota of vaginal samples had an increased risk of 9.048 times for infertility than those with normal lactobacilli microbiota. In addition, the mean lactobacilli/total bacterial mass (TBM) ratio in the vaginal samples was significantly lower in the unexplained infertility patients (38.2% vs.76.3%; p = 0.001).

CONCLUSION

The present study results supported the role of vaginal and endometrial microbiota derangements in unexplained infertility. Many time-consuming and invasive methods are currently used in the diagnosis of infertility. Our study showed that the quantitative determination of lactobacilli/TBM ratio in vaginal specimens, a less invasive and easily obtainable method, could be used as a diagnostic test during the workup of couples with unexplained infertility.

Potential biomarkers of infertility associated with microbiome imbalances

PROBLEM

The aim of this study was to investigate the possible relationship between vaginal/rectal microbiome disbalances and miRNA expression with infertility.

METHOD OF STUDY

Observational, exploratory, preliminary study. A total of 287 multiple IVF failure infertile patients were recruited. Twenty fertile women, not IVF failure, were recruited as the control group. Swab samples were collected from the vagina and rectum. Microbial composition by NGS and miRNA expression by real-time PCR of vaginal and rectal samples was measured. Immunometabolic markers from blood (insulin, vitamin D, LDL-cholesterol, ANA, TPO, Tg, and ASCA antibodies) and saliva (sIgA) were analyzed.

RESULT(S)

Infertile patients showed a lower bacterial richness and increased Firmicutes/Bacteroidetes ratio at rectal level and an increased Lactobacillus brevis/Lactobacillus iners ratio in vaginal samples regarding the fertile group. In the same rectal swab samples, we found that miR-21-5p, which is associated with tight junction disruption and yeast overgrowth, is upregulated and that miR-155-5p, which is associated with inflammation, is overexpressed in the unexplained infertile group (*p < .05). These deregulated miRNAs were also upregulated in the vaginal samples from the same patients (*p < .05).

CONCLUSION

miRNAs could be potential biomarkers of the inflammatory impact of microbiome disbalances in unexplained infertile women.

Pelvic inflammatory disease in the adolescent and young adult: An update

Pelvic inflammatory disease (PID) is an infection of the female upper genital tract that is typically polymicrobial with classic core involvement of Neisseria gonorrhoeae and/or Chlamydia trachomatis, though other endogenous flora from the vagino-cervical areas can be involved as well. It is often a sexually transmitted disease but other etiologic routes are also noted. A variety of risk factors have been identified including adolescence, young adulthood, adolescent cervical ectropion, multiple sexual partners, immature immune system, history of previous PID, risky contraceptive practices and others. An early diagnosis and prompt treatment are necessary to reduce risks of PID complications such as chronic pelvic pain, ectopic pregnancy and infertility. Current management principles of PID are also reviewed. It is important for clinicians to screen sexually active females for common sexually transmitted infections such as Chlamydia trachomatis and provide safer sex education to their adolescent and young adult patients. Clinicians should provide comprehensive management to persons with PID and utilize established guidelines such as those from the US Centers for Disease Control and Prevention (CDC).

Exploring the global vaginal microbiome and its impact on human health

Around the world, more than 175,000,000 women are diagnosed every year with gynaecological disease, in many cases contributing to high morbidity and mortality. For this reason, knowledge of the composition of the vaginal microbiome and its variations represents a real health challenge, as this is key to improving therapeutic management. This review traces the history of the poorly known vaginal microbiome and focuses on the latest findings concerning this ecosystem. Studies in the past decade have targeted complex bacterial communities within the vagina. However, due to the development of technology and the emergence of next generation sequencing (NGS), the exact definition of the vaginal microbiome has changed and can no longer be linked solely to the presence of bacteria. In order to reach a global view of the vaginal microbiome, it is essential to take into account all microorganisms that the vagina harbours, including fungi, viruses, archaea, and candidate phyla radiation. Although these communities represent only a minimal percentage of the vaginal microbiome, they may act as modifiers of its basic physiology and may play a key role in the maintenance of microbial communities, as well as metabolic and immune functions. Studies of the complex interactions between these different microorganisms have recently begun and are not yet fully understood. Results to date indicate that these microbial communities together constitute the first line of defence against infections. On the other hand, the slightest disturbance in this microbiome may lead to disease. For this reason, enhanced knowledge of these associations is critical to better identify predispositions to certain illnesses, which may open new therapeutic avenues. Currently however, only the tip of the iceberg is understood and current research on this ecosystem is revolutionising our knowledge and understanding of human health and disease.

Composition of the vaginal microbiota during pregnancy in women living in sub-Saharan Africa: a PRISMA-compliant review

BACKGROUND

The vaginal microbiota (VMB) are the set of microorganisms residing in the human vagina. During pregnancy, their composition is Lactobacillus-dominant in most Caucasian women. Previous studies suggest that the VMB of women with African ancestry is more likely to be non-Lactobacillus dominant (dysbiotic) compared to other populations, and possibly relate to the high incidence of pregnancy complications, such as preterm birth. This work reviewed the literature on VMB composition in pregnant women from sub-Saharan Africa.

METHODS

A search was conducted in PubMed and Embase databases following PRISMA guidelines. Observational and intervention studies analysing VMB communities from sub-Saharan African pregnant women using molecular techniques were included.

RESULTS

Ten studies performed in seven sub-Saharan African countries were identified. They independently showed that Lactobacillus-dominant VMB (particularly L. iners or L. crispatus) or VMB containing Lactobacilli are the most prevalent, followed by a more diverse anaerobe-dominant VMB, in the studied populations. The majority of pregnant women with a sexually-transmitted infection had a Lactobacillus-dominant VMB, but with a significantly higher presence of anaerobic species.

CONCLUSION

In agreement with studies performed in other populations, Lactobacillus species are the most prevalent VMB species during pregnancy in sub-Saharan African women. The frequency of diverse anaerobe-dominant VMB is high in these populations. In Africa, studies on VMB in pregnancy are scant, heterogeneous in methodology, and knowledge remains limited. More insights on VMB composition and their possible sequalae among these populations is needed.

Cervicovaginal Microbiome after Cervical Intraepithelial Neoplasia Treatment. A Protocol for Systematic Review and Meta-Analysis

(1) Background: The microbiome consists of microorganisms from various kingdoms with numerous physical and chemical properties Lactobacillus species constitute the highest percentage of healthy cervical and vaginal microbiota. Dysbiosis may cause adverse outcomes, e.g., bacterial vaginosis, pelvic inflammatory disease and pregnancy complications. The cervicovaginal microbiome might contribute to the development of a persistent HPV infection—the main risk factor of cervical cancer—and influence progression to malignancy The aim is to perform a systematic review of current literature and a meta-analysis regarding microbiome changes after cervical intraepithelial neoplasia treatment. (2) Methods: We will search PubMed, Scopus, Google Scholar and Embase Database and trace citations in the reference sections. Randomized and non-randomized controlled studies, case–control and cohort studies published between January 2000 and May 2021 will be included in the study protocol. The following keywords will be used: ‘microbiome’, ‘vaginal microbiome’, ‘cervical microbiome’, ‘cervical neoplasia treatment’, ’conization’, ‘electroconization’, and ‘electrosurgical treatment’. Statistical analyses will be performed using RevMan 5.4. (3) Results: The results will be published as a peer-reviewed article. (4) Conclusions: The study will show which forms of intraepithelial neoplasia treatment change the cervicovaginal microbiome. Finding the best form of treatment by studying the cervicovaginal microbiome after various forms of treatment is essential. Patients would benefit not only from the treatment of the initial disease but also the management of dysbiosis, which might underlie other pathologies.

Forensic Analysis of Human Microbiome in Skin and Body Fluids Based on Geographic Location

High-throughput DNA sequencing technologies have facilitated the in silico forensic analysis of human microbiome. Specific microbial species or communities obtained from the crime scene provide evidence of human contacts and their body fluids. The microbial community is influenced by geographic, ethnic, lifestyle, and environmental factors such as urbanization. An understanding of the effects of these external stressors on the human microbiome and determination of stable and changing elements are important in selecting appropriate targets for investigation. In this study, the Forensic Microbiome Database (FMD) (http://www.fmd.jcvi.org) containing the microbiome data of various locations in the human body in 35 countries was used. We focused on skin, saliva, vaginal fluid, and stool and found that the microbiome distribution differed according to the body part as well as the geographic location. In the case of skin samples, Staphylococcus species were higher than Corynebacterium species among Asians compared with Americans. Holdemanella and Fusobacterium were specific in the saliva of Koreans and Japanese populations. Lactobacillus was found in the vaginal fluids of individuals in all countries, whereas Serratia and Enterobacter were endemic to Bolivia and Congo, respectively. This study is the first attempt to collate and describe the observed variation in microbiomes from the forensic microbiome database. As additional microbiome databases are reported by studies worldwide, the diversity of the applications may exceed and expand beyond the initial identification of the host.

Pre-Pregnancy Diet and Vaginal Environment in Caucasian Pregnant Women: An Exploratory Study

Vaginal microbes and their metabolic products have crucial functions, affecting local immunity development and maternal-fetal health. The composition of the vaginal microbiome can vary in response to various factors, including body mass index (BMI), and diet. In this study we get new insights into the vaginal ecosystem of Caucasian women (n = 24) at the first trimester of pregnancy, assessing whether pre-pregnancy diet can affect the structure of the vaginal environment in terms of bacterial composition and vaginal metabolite concentration. We characterized 1) the vaginal bacterial composition (Nugent score), 2) the vaginal metabolic profiles (¹H-NMR spectroscopy), and 3) the dietary nutrient intake by means of a validated food frequency questionnaire. Pre-pregnancy BMI was negatively related to vaginal health status, indicating that women who begin pregnancy overweight/obese have a greater occurrence of vaginal dysbiosis during pregnancy. A lactobacilli-dominated vaginal microbiota was negatively associated with higher pre-pregnancy intake of animal-sourced protein. Conversely, a higher pre-pregnancy consumption of total carbohydrates and sugars seemed to be a protective factor for vaginal health. The vaginal environment of BV-women was characterized by higher levels of biogenic amines and organic acids, whereas higher levels of phenylpropionate and diverse amino acids were fingerprints of a healthy vaginal status. A significant association between a higher pre-pregnancy BMI and several dysbiosis-related vaginal metabolites was also found. Our study shed light on the role of pre-pregnancy BMI and diet on the vaginal environment during pregnancy, underlining the importance of limiting protein intake from animal foods to maintain a healthy lactobacilli-dominated microbiota.

The association between the vaginal microenvironment and fecundability: a register-based cohort study among Chinese women

OBJECTIVE

To evaluate the association between the vaginal microenvironment and fecundability among women.

DESIGN

Register-based nationwide cohort study.

SETTING

Chinese National Free Pre-conception Check-up Project from 2015 to 2018.

POPULATION

Our study included a total of 3 388 554 eligible women who were attempting to become pregnant.

METHOD

We assessed the vaginal microenvironment at baseline by considering four indices: vaginal pH, clue cell examination, whiff test and vaginal cleanliness grading. If any of these indicators was abnormal, the vaginal microenvironment was defined as poor. Propensity score matching was used to control for potential confounders and reduce bias. Logistic models were used to estimate the fecundability odds ratios (FORs) after adjustment for covariates.

MAIN OUTCOME MEASURES

Achievement of a pregnancy within 1 year.

RESULTS

Of the total study population, 379 718 women (11.2%) had a poor vaginal microenvironment and their pregnancy rate after 1 year was significantly lower than the group with a normal microenvironment (71.8% versus 76.1%, P < 0.001). After adjusting for potential confounders, the women with a poor vaginal microenvironment were associated with a 9% reduction in fecundability compared with the normal microenvironment group (FOR 0.91, 95% CI 0.90-0.92). The adverse effects of a poor vaginal microenvironment were stronger among multipara (FOR 0.89, 95% CI 0.87-0.90) or women with irregular menstruation (FOR 0.86, 95% CI 0.84-0.89).

CONCLUSION

There was a negative association between a poor vaginal microenvironment and the fecundability of women. These findings highlight the significance of assessing the vaginal microenvironment during pre-pregnancy health examinations.

TWEETABLE ABSTRACT

Women with a poor vaginal microenvironment were associated with a reduction in fecundability.

Veillonellaceae family members uniquely alter the cervical metabolic microenvironment in a human three-dimensional epithelial model

Bacterial vaginosis (BV) is a gynecologic disorder characterized by a shift in cervicovaginal microbiota from Lactobacillus spp. dominance to a polymicrobial biofilm composed of diverse anaerobes. We utilized a well-characterized human three-dimensional cervical epithelial cell model in conjunction with untargeted metabolomics and immunoproteomics analyses to determine the immunometabolic contribution of three members of the Veillonellaceae family: Veillonella atypica, Veillonella montpellierensis and Megasphaera micronuciformis at this site. We found that Veillonella spp. infections induced significant elevation of polyamines. M. micronuciformis infections significantly increased soluble inflammatory mediators, induced moderate levels of cell cytotoxicity, and accumulation of cell membrane lipids relative to Veillonella spp. Notably, both V. atypica and V. montpellierensis infections resulted in consumption of lactate, a key metabolite linked to gynecologic and reproductive health. Collectively our approach and data provide unique insights into the specific contributions of Veillonellaceae members to the pathogenesis of BV and women's health.

Results from a large cross-sectional study assessing Chlamydia trachomatis, Ureaplasma spp. and Mycoplasma hominis urogenital infections in patients with primary infertility

Female and male infertility have been associated to Chlamydia trachomatis, Ureaplasma spp. and Mycoplasma hominis urogenital infections. However, evidence from large studies assessing their prevalence and putative associations in patients with infertility is still scarce. The study design was a cross-sectional study including 5464 patients with a recent diagnosis of couple's primary infertility and 404 healthy control individuals from Cordoba, Argentina. Overall, the prevalence of C. trachomatis, Ureaplasma spp. and M. hominis urogenital infection was significantly higher in patients than in control individuals (5.3%, 22.8% and 7.4% vs. 2.0%, 17.8% and 1.7%, respectively). C. trachomatis and M. hominis infections were significantly more prevalent in male patients whereas Ureaplasma spp. and M. hominis infections were more prevalent in female patients. Of clinical importance, C. trachomatis and Ureaplasma spp. infections were significantly higher in patients younger than 25 years. Moreover, Ureaplasma spp. and M. hominis infections were associated to each other in either female or male patients being reciprocal risk factors of their co-infection. Our data revealed that C. trachomatis, Ureaplasma spp. and M. hominis are prevalent uropathogens in patients with couple's primary infertility. These results highlight the importance of including the screening of urogenital infections in the diagnostic workup of infertility.

The Female Snark Is Still a Boojum: Looking toward the Future of Studying Female Reproductive Biology

Philosophical truths are hidden in Lewis Carroll's nonsense poems, such as "The hunting of the snark." When the poem is used as a scientific allegory, a snark stands for the pursuit of scientific truth, while a boojum is a spurious discovery. In the study of female biology, boojums have been the result of the use of cultural stereotypes to frame hypotheses and methodologies. Although female reproduction is key for the continuation of sexually reproducing species, not only have females been understudied in many regards, but also data have commonly been interpreted in the context of now-outdated social mores. Spurious discoveries, boojums, are the result. In this article, we highlight specific gaps in our knowledge of female reproductive biology and provide a jumping-off point for future research. We discuss the promise of emerging methodologies (e.g., micro-CT scanning, high-throughput sequencing, proteomics, big-data analysis, CRISPR-Cas9, and viral vector technology) that can yield insights into previously cryptic processes and features. For example, in mice, deoxyribonucleic acid sequencing via chromatin immunoprecipitation followed by sequencing is already unveiling how epigenetics lead to sex differences in brain development. Similarly, new explorations, including microbiome research, are rapidly debunking dogmas such as the notion of the "sterile womb." Finally, we highlight how understanding female reproductive biology is well suited to the National Science Foundation's big idea, "Predicting Rules of Life." Studies of female reproductive biology will enable scholars to (1) traverse levels of biological organization from reproductive proteins at the molecular level, through anatomical details of the ovum and female reproductive tract, into physiological aspects of whole-organism performance, leading to behaviors associated with mating and maternal care, and eventually reaching population structure and ecology; (2) discover generalizable rules such as the co-evolution of maternal-offspring phenotypes in gestation and lactation; and (3) predict the impacts of changes to reproductive timing when the reliability of environmental cues becomes unpredictable. Studies in these key areas relative to female reproduction are sure to further our understanding across a range of diverse taxa.

Connecting the Dots: Translating the Vaginal Microbiome Into a Drug

A Lactobacillus-dominated vaginal microbiota (VMB) has been associated with health and considered an important host defense mechanism against urogenital infections. Conversely, depletion of lactobacilli and increased microbial diversity, amplifies the risk of adverse gynecologic and obstetric outcomes. A common clinical condition that exemplifies dysbiosis is bacterial vaginosis (BV). BV is currently treated with antibiotics, but frequently recurs, due in part to persistent dysbiosis and failure of lactobacilli to repopulate the vagina. New treatment options are needed to address BV. The VMB is relatively simple and optimally dominated by one or several species of Lactobacillus. Lactobacillus crispatus is strongly associated with vaginal health and depleted in dysbiosis. Replenishing the dysbiotic VMB with protective L. crispatus CTV-05 is a promising approach to prevent recurrent infections and improve women's health. Here we discuss confirmation of this approach with the microbiome-based biologic drug, LACTIN-V (L. crispatus CTV-05), focusing on prevention of BV recurrence.

The vaginal microbiome as a tool to predict IVF success

PURPOSE OF REVIEW

Herein, we present an overview of the recent microbiome research and findings within the field of reproductive medicine and its relation with the outcome of Assisted reproductive technology (ART). Analyses of the microbiome composition all throughout the female reproductive trace during the process of assisted reproductive techniques are discussed.

RECENT FINDINGS

Only the vaginal microbiome can be sampled without possible risks of contamination. Although this also seems to apply to the cervical microbiome, collection has to be performed with extreme caution. Because of the high risk of cross contamination, results of microbial composition of all other sites of the female reproductive tract have to be interpreted with caution. The vaginal composition prior to the start of hormonal treatment for ART seems to be predictive of in vitro fertilization/in vitro fertilization-intracytoplasmic sperm injection (IVF/IVF-ICSI) outcome, with mainly a highly negative predictive value.

SUMMARY

The local microbiota, especially the absence or presence of specific microbes, within parts of the female reproductive tract seem to be associated with the outcome of ART.

Finding a Balance in the Vaginal Microbiome: How Do We Treat and Prevent the Occurrence of Bacterial Vaginosis?

Bacterial vaginosis (BV) has been reported in one-third of women worldwide at different life stages, due to the complex balance in the ecology of the vaginal microbiota. It is a common cause of abnormal vaginal discharge and is associated with other health issues. Since the first description of anaerobic microbes associated with BV like Gardnerella vaginalis in the 1950s, researchers have stepped up the game by incorporating advanced molecular tools to monitor and evaluate the extent of dysbiosis within the vaginal microbiome, particularly on how specific microbial population changes compared to a healthy state. Moreover, treatment failure and BV recurrence rate remain high despite the standard antibiotic treatment. Consequently, researchers have been probing into alternative or adjunct treatments, including probiotics or even vaginal microbiota transplants, to ensure successful treatment outcomes and reduce the colonization by pathogenic microbes of the female reproductive tract. The current review summarizes the latest findings in probiotics use for BV and explores the potential of vaginal microbiota transplants in restoring vaginal health.

The Microbiome and Gynecologic Cancer: Current Evidence and Future Opportunities

PURPOSE OF REVIEW

We review the emerging evidence regarding the relationship between the microbiota of the gastrointestinal and female reproductive tracts and gynecologic cancer.

RECENT FINDINGS

The microbiome has essential roles in maintaining health. In recent years, the microbiota of the gastrointestinal and female reproductive tracts have been linked to many diseases, including gynecologic cancer. Alterations to the bacterial populations in a microbiota, or dysbiosis, have been shown to favor a pro-carcinogenic state through altered immune responses, dysregulated hormone metabolism, and modulation of the cell cycle. Pre-clinical and clinical studies have emerged, demonstrating that specific bacteria or microbial communities may be associated with increased risk for uterine, ovarian, and cervical cancers. Notably, numerous studies have linked a non-Lactobacillus-dominant vaginal microbiota, composed of anaerobic bacteria, with HPV infection, persistence, and development of invasive cervical cancer. Similarly, next-generation high-throughput sequencing techniques have enabled the characterization of unique microbiotas in patients with malignant and benign gynecologic conditions, shedding light on new associations between bacterial species and gynecologic cancers. Harnessing the power of the microbiome for early diagnosis, therapeutic intervention and modulation creates tremendous potential to optimize gynecologic cancer outcomes in the future.

Microbial mismanagement: how inadequate treatments for vaginal dysbiosis drive the HIV epidemic in women

Women and girls represent a key population driving new HIV infections and persistence of the HIV pandemic. A key determinant of HIV susceptibility is the composition of the vaginal microbiome, which can influence the local immune cell population, inflammation status, and HIV prevention drug levels. While a low-diversity composition dominated by Lactobacillus crispatus is associated with a decreased risk of HIV acquisition, high diversity environments associated with bacterial vaginosis increase risk of HIV. Given the important role of the vaginal microbiome in determining HIV susceptibility, altering the microbiome towards a Lactobacillus-dominated state is an attractive complementary strategy to reduce HIV incidence rates. Here, we provide an overview of the mechanisms by which the vaginal microbiome may contribute to HIV acquisition risk. Furthermore, we address the advantages and limitations of historical treatments and emerging technologies under investigation to modify the vaginal microbiome, including: antibiotics, bacteriophages, probiotics, topicals, and engineered bacteria. By addressing the current state of vaginal microbiome knowledge and strategies for manipulation, we hope to amplify the growing calls for increased resources and research into vaginal microbial health, which will be essential to accelerating preventative efforts amongst the world's most vulnerable populations.

Lifestyle, Maternal Nutrition and Healthy Pregnancy

Healthy lifestyle habits spanning from preconception to postpartum are considered as a major safeguard for achieving successful pregnancies and for the prevention of gestational diseases. Among preconception priorities established by the World Health Organization (WHO) are healthy diet and nutrition, weight management, physical activity, planned pregnancy and physical, mental and psychosocial health. Most studies covering the topic of healthy pregnancies focus on maternal diet because obesity increases the risks for adverse perinatal outcomes, including gestational diabetes mellitus, large for gestational age newborns, or preeclampsia. Thus, foods rich in vegetables, essential and polyunsaturated fats and fibre-rich carbohydrates should be promoted especially in overweight, obese or diabetic women. An adequate intake of micronutrients (e.g. iron, calcium, folate, vitamin D and carotenoids) is also crucial to support pregnancy and breastfeeding. Moderate physical activity throughout pregnancy improves muscle tone and function, besides decreasing the risk of preeclampsia, gestational diabesity (i.e. diabetes associated with obesity) and postpartum overweight. Intervention studies claim that an average of 30 min of exercise/day contributes to long-term benefits for maternal overall health and wellbeing. Other factors such as microbiome modulation, behavioural strategies (e.g. smoking cessation, anxiety/stress reduction and sleep quality), maternal genetics and age, social class and education might also influence the maternal quality of life. These factors contribute to ensure a healthy pregnancy, or at least to reduce the risk of adverse maternal and foetal outcomes during pregnancy and later in life.

The vaginal microbiota composition of women undergoing assisted reproduction: a prospective cohort study

OBJECTIVE

To evaluate the impact of vaginal microbiota on pregnancy outcomes in women undergoing assisted reproduction.

DESIGN

A prospective cohort study.

SETTING

A university-based assisted reproductive technology (ART) centre.

POPULATION

223 women undergoing ART treatment.

METHODS

Prior to embryo transfer, vaginal samples were collected from the posterior fornix. Vaginal microbiota identification was carried out using next-generation sequencing and categorised according to the V3-V4 hypervariable region in the 16S rRNA gene region.

MAIN OUTCOME MEASURES

ART clinical outcomes (implantation, clinical pregnancy rates and live birth rates).

RESULTS

The live birth rate in women with community state type (CST)-I (39%) was higher than that in women with CST-III (21.5%) but the difference was not statistically significant (P = 0.052). The relative abundance of Lactobacillus was lower in women who failed to become pregnant (NP group) (67.71%) than in women who became pregnant (PR group) (79.72%). However, this difference was not statistically significant (P = 0.06). In the NP group, the relative abundance of Streptococcus (7.81%) and Gardnerella (9.40%) was higher than that in the PR group (relative abundance of Streptococcus and Gardnerella was 2.28% and 5.56%, respectively). The abundance of Streptococcus was found to be statistically significantly different between the two study groups (P = 0.014). Linear discriminant analysis (LDA) further validated that Streptococcus had the highest contribution (LDA score >4.0) to the difference between these two groups.

CONCLUSIONS

Streptococcus has the highest contribution to the distinction between the PR and NP groups.

TWEETABLE ABSTRACT

A relatively high abundance of Streptococcus in the vaginal microbiota may be associated with a lower ART success rate.

New Insights into Vaginal Environment During Pregnancy

During pregnancy, the vaginal ecosystem undergoes marked changes, including a significant enrichment with Lactobacillus spp. and profound alterations in metabolic profiles. A deep comprehension of the vaginal environment may shed light on the physiology of pregnancy and may provide novel biomarkers to identify subjects at risk of complications (e.g., miscarriage, preterm birth). In this study, we characterized the vaginal ecosystem in Caucasian women with a normal pregnancy (n = 64) at three different gestational ages (i.e., first, second and third trimester) and in subjects (n = 10) suffering a spontaneous first trimester miscarriage. We assessed the vaginal bacterial composition (Nugent score), the vaginal metabolic profiles (¹H-NMR spectroscopy) and the vaginal levels of two cytokines (IL-6 and IL-8). Throughout pregnancy, the vaginal microbiota became less diverse, being mainly dominated by lactobacilli. This shift was clearly associated with marked changes in the vaginal metabolome: over the weeks, a progressive reduction in the levels of dysbiosis-associated metabolites (e.g., biogenic amines, alcohols, propionate, acetate) was observed. At the same time, several metabolites, typically found in healthy vaginal conditions, reached the highest concentrations at the end of pregnancy (e.g., lactate, glycine, phenylalanine, leucine, isoleucine). Lower levels of glucose were an additional fingerprint of a normal vaginal environment. The vaginal levels of IL-6 and IL-8 were significantly associated with the number of vaginal leukocytes, as well as with the presence of vaginal symptoms, but not with a condition of dysbiosis. Moreover, IL-8 concentration seemed to be a good predictor of the presence of vaginal Candida spp. Cytokine concentrations were negatively correlated to lactate, serine, and glycine concentrations, whereas the levels of 4-hydroxyphenyllactate, glucose, O-acetylcholine, and choline were positively correlated with Candida vaginal loads. Finally, we found that most cases of spontaneous abortion were associated with an abnormal vaginal microbiome, with higher levels of selected metabolites in the vaginal environment (e.g., inosine, fumarate, xanthine, benzoate, ascorbate). No association with higher pro-inflammatory cytokines was found. In conclusion, our analysis provides new insights into the pathophysiology of pregnancy and highlights potential biomarkers to enable the diagnosis of early pregnancy loss.

The effect of different contraceptive methods on the vaginal microbiome

Introduction: Following a historical overview, the effect of different contraceptive methods on vaginal microbiome has been reviewed and summarized.Areas covered: Effects of combined hormonal contraceptives (oral or vaginal) and of progestin only (injectable and implantable), intrauterine devices/systems (copper- or levonorgestrel-releasing), on vaginal microbiome. In addition, mention is made of vaginal rings releasing antiviral drugs and lactic acid.Expert opinion: The vaginal microbiota (VM) is unique in that it is normally dominated by Lactobacillus species providing a degree of protection against infections; this however may vary, depending on the species and strains of Lactobacillus. Bacterial Vaginosis represents the most common dysbiosis of the VM and its prevalence can be influenced by use of contraception. Available evidence indicates that, under the influence of oral or systemically administered female sex hormones, there is apromotion of vaginal eubiosis, with aprevalence of ahealthy VM in which Lactobacilli predominate.

Association of cervicovaginal dysbiosis mediated HPV infection with cervical intraepithelial neoplasia

Cellular transformation to malignancy is a multifactorial process strongly linked with microbiome dysbiosis. The female reproductive tract (FRT) is inhabited by specific Lactobacillus spp which play a significant role in maintaining a homeostatic balance and providing resistance to perturbation. Any imbalance in the resident microbiota of the FRT results in cervicovaginal dysbiosis and increased predisposition to viral and bacterial infections. In the present review, we discuss the critical role played by the cervicovaginal microbiome in maintaining cervicovaginal homeostasis. Loss of the mutualistic relationship between cervicovaginal microbiota and the host leads to increased susceptibility to Human papilloma virus (HPV) infection. HPV in coinfection with Chlamydia trachomatis has been linked with increased risk for cellular transformation. The progression to cervical neoplasia is a multistep process regulated by cellular and epigenetic changes mediated by oncogenes and miRNA. Exosomes derived from the infected cells play an important role in the pathological development and progression to cervical neoplasia as they harbor the regulatory molecules like miRNA, proteins and prooncogenic factors which may facilitate cellular transformation.

Sodium bicarbonate gels: a new promising strategy for the treatment of vulvovaginal candidosis

Vulvovaginal candidosis (VVC), caused mainly by the yeast Candida albicans, is the second most prevalent vaginal infection. It has been found to have a large impact on women's quality of life, self-esteem and routines. The prevalence of recurrent vulvovaginal candidosis (RVVC) remains high so the development of alternative treatments is needed. The main objective of this study was to develop and characterize sodium bicarbonate gels to treat VVC. We described key formulation characteristics and analyzed their influence on in vitro performance evaluations. The potential to inhibit Candida albicans's growth, the pH, osmolality, viscosity and rheological performance in contact with vaginal fluid simulant and the bioadhesion's profile (using a vaginal ex vivo porcine model) were studied for all formulations. Among the formulations, formulation C (5% sodium bicarbonate, 1% carbomer and 94% water) was the most effective in inhibiting the C. albicans' growth. This gel presented the same potential (the same MIC 2.5%) to inhibit other etiological agents of VVC (C. glabrata, C. krusei, C. tropicalis and C. parapsilosis) for all species tested. Additionally, sensorial characteristics of gel C were in accord with users' preferences. This gel exhibited physicochemical characteristics acceptable for short term treatments, suggesting good overall performance for the treatment of VVC. Furthermore, Gel C was biocompatible with the HeLa cell line (MTT assay) and was classified as a non-severe irritant in the HET-CAM assay (irritation score 4 ± 1). Overall, gel C was deemed the best performing of the set tested, and suitable for further development.

Cervical Gardnerella vaginalis in women with preterm prelabor rupture of membranes

Objective

To determine the association between microbial invasion of the amniotic cavity (MIAC) and/or intra-amniotic inflammation (IAI) and the cervical prevalence of Gardnerella vaginalis DNA in pregnancies with preterm prelabor rupture of membrane (PPROM).

Method

In total, 405 women with singleton pregnancies complicated with PPROM were included. Cervical fluid and amniotic fluid samples were collected at the time of admission. Bacterial and G. vaginalis DNA were assessed in the cervical fluid samples using quantitative PCR technique. Concentrations of interleukin-6 and MIAC were evaluated in the amniotic fluid samples. Loads of G. vaginalis DNA ≥ 1% of the total cervical bacterial DNA were used to define the cervical prevalence of G. vaginalis as abundant. Based on the MIAC and IAI, women were categorized into four groups: with intra-amniotic infection (both MIAC and IAI), with sterile IAI (IAI without MIAC), with MIAC without IAI, and without either MIAC or IAI.

Results

The presence of the abundant cervical G. vaginalis was related to MIAC (with: 65% vs. without: 44%; p = 0.0004) but not IAI (with: 52% vs. without: 48%; p = 0.70). Women with MIAC without IAI had the highest load of the cervical G. vaginalis DNA (median 2.0 × 10⁴ copies DNA/mL) and the highest presence of abundant cervical G. vaginalis (73%).

Conclusions

In women with PPROM, the presence of cervical G. vaginalis was associated with MIAC, mainly without the concurrent presence of IAI.

Impact of endometrial microbiome on fertility

Background

Next-generation sequencing isolates culturable and unculturable bacteria from the female reproductive tract. Current literatures surrounding the impact of endometrial microbiome on fertility are reviewed.

Main body

An abnormal endometrial microbiota has been associated with implantation failure pregnancy loss and other gynecological and obstetrical conditions. Identification of endometrial dysbiosis as a new cause of infertility opens a new microbiological field in the evaluation of endometrial factor, highlighting the relevance of assessing the uterine microbiota in infertile patients to restore a favorable endometrial flora in those patients with altered uterine microbiota to improve and personalize the clinical care of infertile patients. Understanding the significance of microbiome in the endometrium may completely change the therapeutic approach in the treatment of this part of the reproductive tract.

Conclusion

Investigation of the endometrial microbiota may be a future tool for improving reproductive outcomes in infertile patients. Further well-designed studies are required to establish its role in the evaluation and treatment of infertile patients

[Update of Chlamydia trachomatis infection]

Chlamydia trachomatis (CT) is the most common sexually transmitted bacterial infection worldwide. It is asymptomatic in most cases and mainly affects young women, with potential long term sequelae (pelvic inflammatory disease, tubal infertility, obstetric complications). The impact on male fertility is controversial. Screening methods as well as antibiotics use have recently been reassessed due to resistance phenomena and the negative effect on the urogenital microbiota. Positive CT serology may be indicative of tuboperitoneal pathology, which may not be noticed on hysterosalpingography. New research on single-nucleotide polymorphisms (SNPs) aims to establish a patient profile at higher risk of infectious tubal damage due to CT. CT seropositivity is also associated with decreased spontaneous pregnancy rates and is a predictive factor for obstetrical complications.

Application of Ligilactobacillus salivarius CECT5713 to Achieve Term Pregnancies in Women with Repetitive Abortion or Infertility of Unknown Origin by Microbiological and Immunological Modulation of the Vaginal Ecosystem

In this study, the cervicovaginal environment of women with reproductive failure (repetitive abortion, infertility of unknown origin) was assessed and compared to that of healthy fertile women. Subsequently, the ability of Ligilactobacillus salivarius CECT5713 to increase pregnancy rates in women with reproductive failure was evaluated. Vaginal pH and Nugent score were higher in women with reproductive failure than in fertile women. The opposite was observed regarding the immune factors TGF-β 1, TFG-β 2, and VEFG. Lactobacilli were detected at a higher frequency and concentration in fertile women than in women with repetitive abortion or infertility. The metataxonomic study revealed that vaginal samples from fertile women were characterized by the high abundance of Lactobacillus sequences, while DNA from this genus was practically absent in one third of samples from women with reproductive failure. Daily oral administration of L. salivarius CECT5713 (~9 log₁₀ CFU/day) to women with reproductive failure for a maximum of 6 months resulted in an overall successful pregnancy rate of 56%. The probiotic intervention modified key microbiological, biochemical, and immunological parameters in women who got pregnant. In conclusion, L. salivarius CECT5713 has proved to be a good candidate to improve reproductive success in women with reproductive failure.

Cervicovaginal microbiota dysbiosis correlates with HPV persistent infection

HPV persistent infection is a main event leading to the development of cervical intraepithelial neoplasia and cervical cancer. Earlier to distinguish HPV persistent and transient infection is meaningful but the methods are limited. This study used 16S rDNA sequencing to determine the cervicovaginal microbiota of HPV persistent infection, transient infection and health women. Sequences analysis was performed and according to subsequent statistical analysis, the structure of cervicovaginal microbiota of healthy and transient infection individuals is relatively single, Firmicutes occupy the main composition. However, that of the HPV persistent infection presented a complicated trend and the abundance of Proteobacteria, Actinobacteria, Bacteroidetes and Fusobacteria was higher. The significance p-values of the average species abundance of Firmicutes, Proteobacteria and Bacteroides between HPV persistent and transient infection groups were 0.003, 0.018 and 0.005, respectively. The study also found 36 biomarkers of cervicovaginal microbiota dysbiosis for LDA score>4 among different groups. At genus level, Prevotella, Sphingomonas and Anaerococcus correlated with HPV persistent infection. At species level, Lactobacillus iners correlated with HPV transient infection. Besides, local immune microenvironment was changed with cervicovaginal microbiota dysbiosis. Interleukin-6 and TNF-α were significantly upregulated in cervical secretions from HPV persistent infection compared with those from transient infection and healthy women. Peripheral blood Regulatory T cells and myeloid-derived suppressor cells in patients with HPV persistent infection were also significantly increased. In conclusion, this study identified cervicovaginal microbiota dysbiosis closely related to HPV persistent infection, which provided a new idea and method for the prevention of cervical cancer.

Identification of Vaginal Microbial Communities Associated with Extreme Cervical Shortening in Pregnant Women

The vaginal microbiota plays a critical role in pregnancy. Bacteria from Lactobacillus spp. are thought to maintain immune homeostasis and modulate the inflammatory responses against pathogens implicated in cervical shortening, one of the risk factors for spontaneous preterm birth. We studied vaginal microbiota in 46 pregnant women of predominantly Caucasian ethnicity diagnosed with short cervix (<25 mm), and identified microbial communities associated with extreme cervical shortening (≤10 mm). Vaginal microbiota was defined by 16S rRNA gene sequencing and clustered into community state types (CSTs), based on dominance or depletion of Lactobacillus spp. No correlation between CSTs distribution and maternal age or gestational age was revealed. CST-IV, dominated by aerobic and anaerobic bacteria different than Lactobacilli, was associated with extreme cervical shortening (odds ratio (OR) = 15.0, 95% confidence interval (CI) = 1.56–14.21; p = 0.019). CST-III (L. iners-dominated) was also associated with extreme cervical shortening (OR = 6.4, 95% CI = 1.32–31.03; p = 0.02). Gestational diabetes mellitus (GDM) was diagnosed in 10/46 women. Bacterial richness was significantly higher in women experiencing this metabolic disorder, but no association with cervical shortening was revealed by statistical analysis. Our study confirms that Lactobacillus-depleted microbiota is significantly associated with an extremely short cervix in women of predominantly Caucasian ethnicity, and also suggests an association between L. iners-dominated microbiota (CST III) and cervical shortening.

Vaginal microbiota and the potential of Lactobacillus derivatives in maintaining vaginal health

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.

Vaginal Microbiota and Cytokine Microenvironment in HPV Clearance/Persistence in Women Surgically Treated for Cervical Intraepithelial Neoplasia: An Observational Prospective Study

High-risk human papillomaviruses (hrHPVs) are causally related to cervical intraepithelial neoplasia (CIN) and subsequent cervical cancer (CC). The vaginal microbiome has been suggested to play a role in the development of CC, but the effect of conservative surgical treatment on the microbiome and hrHPV elimination has not been elucidated. In this study, we aimed to characterize the vaginal microbiome and inflammatory chemokine profile in 85 women treated for CIN2-CIN3 lesions, before and after surgical CIN removal. The results showed, as expected, a high prevalence of dysbiotic microbiomes and vaginal pro-inflammatory cytokines in the CIN cohort, correlated with disease severity, at the basal level. By contrast, surgical CIN removal induced significant vaginal microbiome variations, and specific microbiome/cytokine profiles were associated with hrHPV clearance/persistence at 6-month follow-up. hrHPV-cleared patients, in fact, showed a specific increase of L. crispatus and decrease of dysbiosis and inflammatory cytokines compared to hrHPV-persistent patients. These data highlight the crosstalk between HPV and the local microbiome, and suggest that vaginal microbiome modulation might represent a novel approach to modifying the natural history of hrHPV-related CC.

Study registration n. ISRCTN34437150 (https://www.isrctn.com/ISRCTN34437150).

Probiotic intervention as a potential therapeutic for managing gestational disorders and improving pregnancy outcomes

Recent molecular investigations have significantly developed our knowledge of the characteristics of the reproductive microbiome and their associations with host responses to provide an ideal milieu for the development of the embryo during the peri-implantation period and throughout pregnancy as well as to provide a successful in vitro fertilization and appropriate reproductive outcomes. In this context, the establishment of microbial homeostasis in the female reproductive tract, in various physiological periods, is a substantial challenge, which appears the application of probiotics can facilitate the achievement of this goal. So that, currently, probiotics due to its safe and natural features can be considered as a novel biotherapeutic approach. In this review, we comprehensively discuss the bacterial, fungal, and viral diversity detected in the reproductive tract, and their associations with the establishment of dysbiosis/eubiosis conditions as well as we present the significant outcomes on probiotic intervention as an efficient biotherapeutic strategy for management of gestational disorders and improve pregnancy outcomes.

Menstruation: science and society

Women's health concerns are generally underrepresented in basic and translational research, but reproductive health in particular has been hampered by a lack of understanding of basic uterine and menstrual physiology. Menstrual health is an integral part of overall health because between menarche and menopause, most women menstruate. Yet for tens of millions of women around the world, menstruation regularly and often catastrophically disrupts their physical, mental, and social well-being. Enhancing our understanding of the underlying phenomena involved in menstruation, abnormal uterine bleeding, and other menstruation-related disorders will move us closer to the goal of personalized care. Furthermore, a deeper mechanistic understanding of menstruation-a fast, scarless healing process in healthy individuals-will likely yield insights into a myriad of other diseases involving regulation of vascular function locally and systemically. We also recognize that many women now delay pregnancy and that there is an increasing desire for fertility and uterine preservation. In September 2018, the Gynecologic Health and Disease Branch of the Eunice Kennedy Shriver National Institute of Child Health and Human Development convened a 2-day meeting, "Menstruation: Science and Society" with an aim to "identify gaps and opportunities in menstruation science and to raise awareness of the need for more research in this field." Experts in fields ranging from the evolutionary role of menstruation to basic endometrial biology (including omic analysis of the endometrium, stem cells and tissue engineering of the endometrium, endometrial microbiome, and abnormal uterine bleeding and fibroids) and translational medicine (imaging and sampling modalities, patient-focused analysis of menstrual disorders including abnormal uterine bleeding, smart technologies or applications and mobile health platforms) to societal challenges in health literacy and dissemination frameworks across different economic and cultural landscapes shared current state-of-the-art and future vision, incorporating the patient voice at the launch of the meeting. Here, we provide an enhanced meeting report with extensive up-to-date (as of submission) context, capturing the spectrum from how the basic processes of menstruation commence in response to progesterone withdrawal, through the role of tissue-resident and circulating stem and progenitor cells in monthly regeneration-and current gaps in knowledge on how dysregulation leads to abnormal uterine bleeding and other menstruation-related disorders such as adenomyosis, endometriosis, and fibroids-to the clinical challenges in diagnostics, treatment, and patient and societal education. We conclude with an overview of how the global agenda concerning menstruation, and specifically menstrual health and hygiene, are gaining momentum, ranging from increasing investment in addressing menstruation-related barriers facing girls in schools in low- to middle-income countries to the more recent "menstrual equity" and "period poverty" movements spreading across high-income countries.

Probiotics and the envisaged role in treating human infertility

Background

Considerable attention is being directed nowadays towards using probiotics as an alternative therapy in treating several human diseases including gastrointestinal tract diseases especially colorectal cancers, cardiovascular diseases, hyperlipidemia, and blood pressure cases. However, infertility as affected by the microbiome and the probable role of probiotics in alleviating infertility problems did not receive the deserved attention, especially in IVF patients with male or female factors.

Main body

In this review, we tried to draw the attention of researchers in the medical settings to the importance of the forthcoming role of probiotics use in elucidating the role of the microbiome in infertile patients. The hope is to attain the best performance of both male and female reproductive systems and to shed some light on infertility problems.

Conclusion

More in vivo experiments are still needed to address many aspects of probiotics like proper administration, exact functional strains, required dose, application method, duration of treatment, and combination with antibiotics before considering probiotics as an alternative treatment.

An unusual cause of female secondary infertility: Hypospadias

Female hypospadias is a very rare congenital anomaly and its impact on fertility has not yet been clearly defined. A 21-year-old woman with hypospadias was admitted with secondary infertility, dyspareunia, and urge symptoms. She was successfully treated with vaginal flap urethroplasty and broad spectrum antibiotics. Postoperatively, her symptoms resolved and she conceived spontaneously and aborted at her 17^th gestational week following premature rupture of membranes suggesting infection. She then conceived spontaneously again and delivered a healthy term baby 30 months after the operation. Female hypospadias may cause chronic pelvic infections, urge symptoms, sexual dysfunction, hence infertility with time. After achieving normal anatomy by vaginal flap urethroplasty, treatment of chronic infections allows restoring normal urologic and sexual functions, and fertility.

The vaginal microbiota in the course of bacterial vaginosis treatment

Bacterial vaginosis (BV) is perceived as a condition of disrupted vaginal microbiota, but remains of unknown aetiology. In this study, vaginal microbiota composition was determined in twenty-one women with BV, before and after treatment with metronidazole or clindamycin. Microbiota composition varied greatly between women and defining a (un)healthy vaginal microbiota state remains elusive, challenging BV diagnosis and treatment. While relative abundance of Lactobacillus increased after antibiotic treatment in two-third of women, its abundance was not associated with treatment outcome. Instead, remaining complaints of abnormal vaginal discharge were more common after metronidazole treatment and associated with increased relative abundance of Ureaplasma.