The vaginal microbiome in health and disease

Leveraging existing 16S rRNA gene surveys to decipher microbial signatures and dysbiosis in cervical carcinogenesis

The presence of dysbiotic cervicovaginal microbiota has been observed to be linked to the persistent development of cervical carcinogenesis mediated by the human papillomavirus (HPV). Nevertheless, the characteristics of the cervical microbiome in individuals diagnosed with cervical cancer (CC) are still not well understood. Comprehensive analysis was conducted by re-analyzing the cervical 16S rRNA sequencing datasets of a total of 507 samples from six previously published studies. We observed significant alpha and beta diversity differences in between CC, cervical intraepithelial neoplasia (CIN) and normal controls (NC), but not between HPV and NC in the combined dataset. Meta-analysis revealed that opportunistic pernicious microbes Streptococcus, Fusobacterium, Pseudomonas and Anaerococcus were enriched in CC, while Lactobacillus was depleted compared to NC. Members of Gardnerella, Sneathia, Pseudomonas, and Fannyhessea have significantly increased relative abundance compared to other bacteria in the CIN group. Five newly identified bacterial genera were found to differentiate CC from NC, with an area under the curve (AUC) of 0.8947. Moreover, co-occurrence network analysis showed that the most commonly encountered Lactobacillus was strongly negatively correlated with Prevotella. Overall, our study identified a set of potential biomarkers for CC from samples across different geographic regions. Our meta-analysis provided significant insights into the characteristics of dysbiotic cervicovaginal microbiota undergoing CC, which may lead to the development of noninvasive CC diagnostic tools and therapeutic interventions.

Highly specific vaginal microbiome signature for gynecological cancers

To investigate the vaginal microbiota signature of patients with gynecologic cancer and evaluate its diagnostic biomarker potential. We incorporated vaginal 16S rRNA-seq data from 529 women and utilized VSEARCH to analyze the raw data. α-Diversity was evaluated utilizing the Chao1, Shannon, and Simpson indices, and β-diversity was evaluated through principal component analysis using Bray-Curtis distances. Linear discriminant analysis effect size (LEfSe) was utilized to determine species differences between groups. A bacterial co-abundance network was constructed utilizing Spearman correlation analysis. A random forest model of gynecologic tumor risk based on genus was constructed and validated to test its diagnostic efficacy. In gynecologic cancer patients, vaginal α-diversity was significantly greater than in controls, and vaginal β-diversity was significantly separated from that of controls; there was no correlation between these characteristics and menopause status among the subject women. Women diagnosed with gynecological cancer exhibited a reduction in the abundance of vaginal Firmicutes and Lactobacillus, while an increase was observed in the proportions of Bacteroidetes, Proteobacteria, Prevotella, Streptococcus, and Anaerococcus. A random forest model constructed based on 56 genus achieved high accuracy (area under the curve = 84.96%) in gynecological cancer risk prediction. Furthermore, there were discrepancies observed in the community complexity of co-abundance networks between gynecologic cancer patients and the control group. Our study provides evidence that women with gynecologic cancer have a unique vaginal flora structure and microorganisms may be involved in the gynecologic carcinogenesis process. A gynecological cancer risk prediction model based on characteristic genera has good diagnostic value.

Inferring stability and persistence in the vaginal microbiome: A stochastic model of ecological dynamics

The interplay of stochastic and ecological processes that govern the establishment and persistence of host-associated microbial communities is not well understood. Here we illustrate the conceptual and practical advantages of fitting stochastic population dynamics models to multi-species bacterial time series data. We show how the stability properties, fluctuation regimes and persistence probabilities of human vaginal microbial communities can be better understood by explicitly accommodating three sources of variability in ecological stochastic models of multi-species abundances: 1) stochastic biotic and abiotic forces, 2) ecological feedback and 3) sampling error. Rooting our modeling tool in stochastic population dynamics modeling theory was key to apply standardized measures of a community's reaction to environmental variation that ultimately depends on the nature and intensity of the intra-specific and inter-specific interaction strengths. Using estimates of model parameters, we developed a Risk Prediction Monitoring (RPM) tool that estimates temporal changes in persistence probabilities for any bacterial group of interest. This method mirrors approaches that are often used in conservation biology in which a measure of extinction risks is periodically updated with any change in a population or community. Additionally, we show how to use estimates of interaction strengths and persistence probabilities to formulate hypotheses regarding the molecular mechanisms and genetic composition that underpin different types of interactions. Instead of seeking a definition of "dysbiosis" we propose to translate concepts of theoretical ecology and conservation biology methods into practical approaches for the management of human-associated bacterial communities.

Ethnic disparity in diagnosing asymptomatic bacterial vaginosis using machine learning

While machine learning (ML) has shown great promise in medical diagnostics, a major challenge is that ML models do not always perform equally well among ethnic groups. This is alarming for women's health, as there are already existing health disparities that vary by ethnicity. Bacterial Vaginosis (BV) is a common vaginal syndrome among women of reproductive age and has clear diagnostic differences among ethnic groups. Here, we investigate the ability of four ML algorithms to diagnose BV. We determine the fairness in the prediction of asymptomatic BV using 16S rRNA sequencing data from Asian, Black, Hispanic, and white women. General purpose ML model performances vary based on ethnicity. When evaluating the metric of false positive or false negative rate, we find that models perform least effectively for Hispanic and Asian women. Models generally have the highest performance for white women and the lowest for Asian women. These findings demonstrate a need for improved methodologies to increase model fairness for predicting BV.

A new hypothesis on BV etiology: dichotomous and crisscrossing categorization of complex versus simple on healthy versus BV vaginal microbiomes

IMPORTANCE

BV may influence as many as one-third of women, but its etiology remains unclear. A traditional view is that dominance by Lactobacillus is the hallmark of a healthy vaginal microbiome and lack of dominance may make women BV-prone. Recent studies show that the human VMs can be classified into five major types, four of which possess type-specific dominant species of Lactobacillus. The remaining one (type IV) is not dominated by Lactobacillus and contains a handful of strictly anaerobic bacteria. Nevertheless, exceptions to the first hypothesis have been noticed from the very beginning, and there is not a definite relationship, suggested yet, between the five VM types and BV status. Here, we propose and test a novel hypothesis that assumes the existence of four VM types from dichotomous crisscrossing of "complex versus simple (high diversity or low dominance versus low diversity or high dominance)" on "healthy versus BV." Consequently, there are simple BV versus complex BV.

Pre- and post-LEEP: analysis of the female urogenital tract microenvironment and its association with sexual dysfunction

Background

The loop electrosurgical excision procedure (LEEP) to treat cervical dysplasia (CD) is known to alter the cervical microbiota, the community of bacteria that play a central role in female genital health. Perturbations to the microbiota of the female urogenital tract (FUT), including the urethra, vagina, and cervix, have been linked with symptoms of sexual dysfunction (SD), though correlations among LEEP, the microenvironment, and SD have not yet been described.

Aims

To characterize the FUT microbiota before and after LEEP and investigate possible associations with SD.

Methods

Females undergoing LEEP for CD were recruited to participate in the study. Urinary samples and vaginal and cervical swabs were collected immediately before and 3 months after treatment. Bacterial communities were characterized by 16S rRNA next-generation sequencing. Self-report surveys assessing demographics, medical history, and sexual function were completed at the same intervals.

Outcomes

Microbiota taxonomy and Female Sexual Function Index (FSFI) scores.

Results

Alpha diversity revealed a significant decrease in species richness in the FUT microbiota post-LEEP. Beta diversity demonstrated significant differences among the cervical, urinary, and vaginal microenvironments pre- and post-LEEP. Lactobacillus spp were the dominant microbial genus in the cervical microenvironment pre- and post-LEEP. Although the vaginal and urinary microenvironments were characterized by Prevotella pre-LEEP, they were colonized by Lactobacillus post-LEEP. Following LEEP, some participants experienced a significant increase in proinflammatory bacteria, including the genera Gardnerella, Megasphaera, Sneathia, Parvimonas, and Peptostreptococcus. Others experienced significant decreases in inflammatory and protective bacteria post-LEEP, including Butyricicoccus, Terriporobacter, Intestinimonas, and Negativibacillus. Overall there were no significant changes in pre- and post-LEEP FSFI scores. However, post-LEEP FSFI scores were seemingly associated with changes in inflammatory bacteria in some participants.

Clinical Implications

There is an overall reduction in FUT microbiota dysbiosis post-LEEP. However, we show variability as some participants experienced persistent dysbiosis of FUT microbiota and elevated FSFI scores, suggesting that therapies to treat dysbiosis of FUT microbiota may reduce FSFI scores, thereby improving SD symptoms.

Strengths and Limitations

We demonstrate novel associations among urogenital sites, microbiota changes, LEEP, and SD. The small sample size and inability of species classification are limitations.

Conclusion

Diverse inflammatory microbiota characterizes CD in the FUT, and LEEP mostly returns microenvironments to a healthy state. However, some participants have persistent inflammatory bacteria post-LEEP, suggesting a non-uniform healing response. This study provides an impetus for future longitudinal studies to monitor and restore FUT microenvironments post-LEEP, aimed at mitigating postoperative SD symptoms.

A Narrative Review Discussing the Obstetric Repercussions Due to Alterations of Personalized Bacterial Sites Developed within the Vagina, Cervix, and Endometrium

BACKGROUND

The reproductive tract microbiota that evolved as an integrative component has been studied intensively in the last decade. As a result, novel research, clinical opportunities, and perspectives have been derived following the close investigation of this microecological environment. This has paved the way for an update to and improvement of the management strategies and therapeutic approaches. However, obscurities, contradictions, and controversies arise regarding the ascension route from the vagina to the endometrium via the cervix, with finality in adverse obstetric outcomes.

METHODS

Starting from these considerations, we aimed to gather all existing data and information from four major academic databases (PubMed, ISI Web of Knowledge, Scopus, and ScienceDirect) published in the last 13 years (2010-2023) using a controlled vocabulary and dedicated terminology to enhance the coverage, identification, and sorting of potentially eligible studies.

RESULTS

Despite the high number of returned entries (n = 804), only a slight percentage (2.73%) of all manuscripts were deemed eligible following two rounds of evaluation. Cumulatively, a low level of Lactobacillus spp. and of other core microbiota members is mandatory, with a possible eubiosis-to-dysbiosis transition leading to an impairment of metabolic and endocrine network homeostasis. This transposes into a change in the pro-inflammatory landscape and activation of signaling pathways due to activity exerted by the bacterial lipopolysaccharides (LPSs)/endotoxins that further reflect a high risk of miscarriage in various stages. While the presence of some pathogenic entities may be suggestive of an adverse obstetric predisposition, there are still pros and cons of the role of specific strains, as only the vagina and cervix have been targeted as opposed to the endometrium, which recently started to be viewed as the key player in the vagina-cervix-endometrium route. Consequently, based on an individual's profile, diet, and regime, antibiotics and probiotics might be practical or not.

CONCLUSIONS

Resident bacteria have a dual facet and are beneficial for women's health, but, at the same time, relaying on the abundance, richness, and evenness that are definitory indexes standing as intermediaries of a miscarriage.

HPV pathogenesis, various types of vaccines, safety concern, prophylactic and therapeutic applications to control cervical cancer, and future perspective

Over 98% of cervical cancers (CC) are caused by regular infections with "high risk" genotype of the human papilloma virus (HPV). However, this is not always the causative factor. Therefore, production of HPV vaccinations represents a significant chance to minimize the risk of CC. Phase III studies for a number of preventative HPV vaccines based on L1-virus-like particle (VLPs) have just been completed and the preliminary results are very convincing. However, there are a lot of practical concerns that need to be resolved before the use of these vaccinations. These vaccines were challenged with obvious queries such as protection time, subject receiving vaccines, time of vaccination, and how to include them into ongoing screening programs. Although these vaccines were 90% effective at preventing HPV infection as these offered only modest advantages for the removal of pre-existing infections. New advancements in the creation of therapeutic vaccinations have been explored for further improvement and post-vaccination surveillance. Therapeutic vaccines attempted to boost cell-mediated immunities and these are detrimental to the infected cell as opposed to neutralizing antibodies (different from prophylactic vaccines).

Fecal microbiota transplantation attenuates Escherichia coli infected outgrowth by modulating the intestinal microbiome

BACKGROUND

Given the crucial role of gut microbiota in animal and human health, studies on modulating the intestinal microbiome for therapeutic purposes have grasped a significant attention, of which the role of fecal microbiota transplantation (FMT) has been emphasized.

METHODS

In the current study, we evaluated the effect of FMT on gut functions in Escherichia coli (E. coli) infection by using mice model. Moreover, we also investigated the subsequently dependent variables of infection, i.e., body weight, mortality, intestinal histopathology, and the expression changes in tight junction proteins (TJPs).

RESULTS

The FMT effectively decreased weight loss and mortality to a certain extent with the restoration of intestinal villi that resulted in high histological scores for jejunum tissue damage (p < 0.05). The effect of FMT on alleviating the reduction of intestinal TJPs was also proved by immunohistochemistry analysis and mRNA expression levels. Moreover, the abundance of health-threatening bacteria, belonging to phylum Proteobacteria, family Enterobacteriaceae and Tannerellaceae, genus Escherichia-Shigella, Sphingomonas, Collinsella, etc., were significantly increased, whereas beneficial bacteria, belonging to phylum Firmicutes, family Lactobacillaceae, genus Lactobacillus were decreased in the gut of infected mice. Furthermore, we sought to investigate the association of clinical symptoms with FMT treatment with modulation in gut microbiota. According to beta diversity, the microbial community of gut microbiota results reflected the similarities between non-infected and FMT groups. The improvement of the intestinal microbiota in FMT group was characterized by the significant high level of beneficial microorganisms with the synergistic decrease of Escherichia-Shigella, Acinetobacter, and other taxa.

CONCLUSION

The findings suggest a beneficial host-microbiome correlation following fecal microbiota transplanatation for controlling gut infections and pathogens-associated diseases.

Large animal models in the study of gynecological diseases

Gynecological diseases are a series of diseases caused by abnormalities in the female reproductive organs or breast, which endanger women's fertility and even their lives. Therefore, it is important to investigate the mechanism of occurrence and treatment of gynecological diseases. Animal models are the main objects for people to study the development of diseases and explore treatment options. Large animals, compared to small rodents, have reproductive organs with structural and physiological characteristics closer to those of humans, and are also better suited for long-term serial examinations for gynecological disease studies. This review gives examples of large animal models in gynecological diseases and provides a reference for the selection of animal models for gynecological diseases.

Detect feature edges for diagnosis of bacterial vaginosis

One of the most common diseases among women of reproductive age is bacterial vaginosis (BV). However, the etiology of BV remains unknown. In this study, we modeled the temporal sample of the vaginal microbiome as a network and investigated the relationship between the network edges and BV. Furthermore, we used feature selection algorithms including decision tree (DT) and ReliefF (RF) to select the network feature edges associated with BV and subsequently validated these feature edges through logistic regression (LR) and support vector machine (SVM). The results show that: machine learning can distinguish vaginal community states (BV, ABV, SBV, and HEA) based on a few feature edges; selecting the top five feature edges of importance can achieve the best accuracy for the feature selection and classification model; the feature edges selected by DT outperform those selected by RF in terms of classification algorithm LR and SVM, and LR with DT feature edges is more suitable for diagnosing BV; two feature selection algorithms exhibit differences in the importance of ranking of edges; the feature edges selected by DT and RF cannot construct sub-network associated with BV. In short, the feature edges selected by our method can serve as indicators for personalized diagnosis of BV and aid in the clarification of a more mechanistic interpretation of its etiology.

Microbiota of female genital tract – functional overview of microbial flora from vagina to uterine tubes and placenta

Microorganisms and eukaryotic human cells coexist in synergistic relationships in nearly every niche of the human body. The female genital tract consisting of the vagina, uterus with its cervix and endometrium, uterine tubes and ovaries – harbors its own typical microbiota, which accounts for 9 % of the total bacterial population in females. To this organ system, we also assigned the microbiome of the placenta, which has not been studied much until now. Among the spectrum of microbial species, the female genital tract is mainly dominated by Lactobacillus species, which are considered to be one of the simplest yet most important microbial communities. However, this relationship between macro- and micro-organisms seems to have a number of physiological functions, e.g., the vaginal and cervical microbiota have unique impact on reproductive health. The aim of this review was to provide current view on female genital tract microbiota and its role in reproductive health. We describe in detail the association of vaginal or tubal epithelium with microbiota or the role of microbiota in normal placental function.

Microbiota of female genital tract - functional overview of microbial flora from vagina to uterine tubes and placenta

Microorganisms and eukaryotic human cells coexist in synergistic relationships in nearly every niche of the human body. The female genital tract consisting of the vagina, uterus with its cervix and endometrium, uterine tubes and ovaries - harbors its own typical microbiota, which accounts for 9 % of the total bacterial population in females. To this organ system, we also assigned the microbiome of the placenta, which has not been studied much until now. Among the spectrum of microbial species, the female genital tract is mainly dominated by Lactobacillus species, which are considered to be one of the simplest yet most important microbial communities. However, this relationship between macro- and micro-organisms seems to have a number of physiological functions, e.g., the vaginal and cervical microbiota have unique impact on reproductive health. The aim of this review was to provide current view on female genital tract microbiota and its role in reproductive health. We describe in detail the association of vaginal or tubal epithelium with microbiota or the role of microbiota in normal placental function.

Association between Cervical Microbiota and HPV: Could This Be the Key to Complete Cervical Cancer Eradication?

Simple Summary

The microbiota can modulate immune responses and modify the physiology of the human organism, thereby increasing infective risks and a neoplastic predisposition. In this review, we focus on the composition of the cervical microbiota, to identify the risk of developing Cervical Intraepithelial Neoplasia and better understand the interaction between cervico-vaginal microbiota and human papillomavirus as a means of promoting the identification of new therapeutic strategies. In fact, no therapy for HPV is yet available. A better understanding of the cervical micro-environment could be a key element allowing complete viral clearance to be achieved in largely affected populations.

Abstract

The heterogeneity of the cervico-vaginal microbiota can be appreciated in various conditions, both pathological and non-pathological, and can vary according to biological and environmental factors. Attempts are still in course to define the interaction and role of the various factors that constitute this community of commensals in immune protection, inflammatory processes, and the onset of precancerous lesions of the cervical epithelium. Despite the many studies on the relationship between microbiota, immunity, and HPV-related cervical tumors, further aspects still need to be probed. In this review article, we will examine the principal characteristics of microorganisms commonly found in cervico-vaginal specimens (i) the factors that notoriously condition the diversity and composition of microbiota, (ii) the role that some families of organisms may play in the onset of HPV-dysplastic lesions and in neoplastic progression, and (iii) possible diagnostic-therapeutic approaches.

Contributions of Human-Associated Archaeal Metabolites to Tumor Microenvironment and Carcinogenesis

There is increasing awareness that archaea are interrelated with human diseases (including cancer). Archaea utilize unique metabolic pathways to produce a variety of metabolites that serve as a direct link to host-microbe interactions. However, knowledge on the diversity of human-associated archaea is still extremely limited, and less is known about the pathological effects of their metabolites to the tumor microenvironment and carcinogenesis. In the present study, we performed a large-scale analysis of archaea and their cancer-related metabolites across different body sites using >44,000 contigs with length >1,000 bp. Taxonomy annotation revealed that the occurrence and diversity of archaea are higher in two body sites, the gut and the oral cavity. Unlike other human-associated microbes, the nonmetric multidimensional scaling (NMDS) and permutational multivariate analysis of variance (PERMANOVA) analyses have shown no difference of archaeal compositions between Easterners and Westerners. Likewise, protein annotation suggests that genes encoding cancer-related metabolites (e.g., short-chain fatty acids and polyamines) are more prevalent and diverse in gut and oral samples. Archaea carrying these metabolites are restricted to Euryarchaeota and the TACK superphylum (Thaumarchaeota, Aigarchaeota, Crenarchaeota, and Korarchaeota), especially methanogenic archaea, such as Methanobacteria. IMPORTANCE More evidence suggests that archaea are associated with human disease, including cancer. Here, we present the first framework of the diversity and distribution of human-associated archaea across human body sites, such as gut and oral cavity, using long contigs. Furthermore, we unveiled the potential archaeal metabolites linking to different lineages that might influence the tumor microenvironment and carcinogenesis. These results could open a new door to the guidance of diagnosing cancer and developing new treatment strategies.

The effects of genital myiasis on the diversity of the vaginal microbiota in female Bactrian camels

Background

Genital myasis is one of the most important diseases that affects the reproductive organs of Bactrian camels in which can cause serious mechanical damage to the vaginal tissue. The accumulation of bacteria in the vagina of female camels can affect their health and reproductive ability. The effect of this damage is commonly manifested in the vaginal flora and vaginal mucosal immune system. Therefore, this investigation is a study of the diversity of the vaginal flora and the differences between healthy Bactrian camels and those suffering from genital myiasis.

Results

Vaginal microbiota samples were collected from two groups of female Bactrian camels of the same age. An Illumina MiSeq was used to sequence the 16S rRNA V3-V4 hypervariable sequence in the samples. The results showed that the vaginal microflora of the infected camels had a significantly greater operational taxonomic unit (OTU) value. According to the assessment of the alpha diversity index and the vaginal pH, the diversity index of the infected camel flora was higher than that of the normal camel flora, and the vaginal pH was lower than that of the normal camels (p < 0.01). There were no significant differences between the two groups in the abundance of dominant genera in the Bactrian camel vagina (P > 0.05), indicating that the certain stability is maintained.

Conclusions

Overall, this comparison revealed the differences and similarities between the vaginal microbiota of Bactrian camels in various health statues. In addition, these data provide a reference point for understanding the types of bacteria that cause genital myiasis affecting the healthy development of Bactrian camels.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12917-022-03189-5.

The female reproductive tract virome: understanding the dynamic role of viruses in gynecological health and disease

The human body is inhabited by a large and complex network of commensal and predatory eukaryotic viruses and bacteriophages collectively termed the virome. Despite being the most abundant and genetically diverse biological entities on the planet, the impact of viruses on human health especially within the female reproductive tract (FRT) remains understudied. To better appreciate current knowledge regarding the dynamic role of viruses in FRT health and disease, in this review we highlight the known constituents of the FRT virome, transkingdom interactions within the FRT and their influence on gynecological disease. A better understanding of the FRT virome may pave the way toward improved outcomes in gynecological, reproductive, and neonatal health.

The Vaginal Microbiome: V. Therapeutic Modalities of Vaginal Microbiome Engineering and Research Challenges

OBJECTIVE

This series of articles, titled The Vaginal Microbiome (VMB), written on behalf of the International Society for the Study of Vulvovaginal Disease, aims to summarize the recent findings and understanding of the vaginal bacterial microbiota, mainly regarding areas relevant to clinicians specializing in vulvovaginal disorders.

MATERIALS AND METHODS

A search of PubMed database was performed, using the search terms "vaginal microbiome" with "treatment," "diagnosis," and "research." Full article texts were reviewed. Reference lists were screened for additional articles.

RESULTS

The currently available approaches for treating vaginitis or attempting to modulate the VMB are often insufficient. It has traditionally relied on the use of antibiotics, antiseptics, and antifungals. The fifth and last article of this series discusses the new and/or alternative therapeutic modalities. It addresses the role of probiotics, prebiotics and symbiotics, activated charcoal, biofilm disrupting agents, acidifying agents, phage therapy, and the concept of vaginal microbiome transplant. The challenges facing the research of VMB, including the clinical impact of microbiome manipulation, classification, and new diagnostic approaches are discussed.

CONCLUSIONS

Microbiome research has grown dramatically in recent years, motivated by innovations in technology and decrease in analysis costs. This research has yielded huge insight into the nature of microbial communities, their interactions, and effects with their hosts and other microbes. Further understanding of the bacterial, fungal, phage, and viral microbiomes in combination with host genetics, immunologic status, and environmental factors is needed to better understand and provide personalized medical diagnostics and interventions to improve women's health.

Vaginal Microbiota Changes in Patients With Premature Ovarian Insufficiency and Its Correlation With Ovarian Function

OBJECTIVES

To reveal the characteristics of vaginal microbiota in premature ovarian insufficiency (POI) patients and their relationship with ovarian function.

MATERIALS AND METHODS

In this case-control study, the vaginal bacterial composition of 30 POI patients and 26 healthy women of comparable age was assessed by 16S rRNA gene sequencing targeting the V3-V4 hypervariable regions. The metabolic functions of vaginal microflora were preliminarily predicted through the PICRUSt2 analysis. Redundancy analysis and Spearman's correlation analyzed the relationships between vaginal microbiota and ovarian function indicators.

RESULTS

Actinobacteria, Atopobium, and Gardnerella were significantly increased in POI patients. Their increments were significantly negatively correlated with anti-müllerian hormone (AMH) and inhibin B, and positively correlated with follicle-stimulating hormone (FSH) and luteinizing hormone (LH). While Bifidobacterium was significantly decreased in POI patients. Its relative abundance was significantly positively correlated with AMH and negatively correlated with FSH and LH. Then, POI patients included in this study were divided into POI (25 < FSH ≤ 40) (n = 9) and premature ovarian failure (POF) (FSH > 40) (n = 21) subgroups according to serum FSH levels. Compared with the controls, Firmicutes and Lactobacillus were significantly decreased only in POF (FSH > 40) patients, while no difference was observed in POI (25 < FSH ≤ 40) patients. Lactobacillus was negatively correlated with FSH. Firmicutes was significantly reduced and Actinobacteria was significantly increased in POF (FSH > 40) patients compared with POI (25 < FSH ≤ 40) patients. The key bacterial taxa Gardnerella and Atopobium showed potency in predicting POI.

CONCLUSIONS

Here we demonstrated significant changes in the vaginal microbiota of POI patients, and these changes were significantly correlated with reduced ovarian reserve, endocrine disruption, and symptoms of perimenopausal syndrome. Differences in vaginal microbiota between POI (25 < FSH ≤ 40) and POF (FSH > 40) patients were also identified. These findings may provide new evidence for the relationship between vaginal microbiota and ovarian function.

Characterization of the Gastrointestinal and Reproductive Tract Microbiota in Fertile and Infertile Pakistani Couples

Simple Summary

We describe microbial taxa associated with the gastrointestinal and reproductive tracts of married Pakistani couples. We highlight differences in microbial composition and diversity that are associated with fertile and infertile couples and provide a baseline for future in-depth studies to target the association of the human microbiome with infertility.

Abstract

The human microbiota is recognized as a vital “virtual” organ of the human body that influences human health, metabolism, and physiology. While the microbiomes of the gut, oral cavity, and skin have been extensively studied in the literature, relatively little work has been done on characterizing the microbiota of the human reproductive tract organs, and specifically on investigating its association to fertility. Here, we implemented a 16S ribosomal RNA (rRNA) amplicon sequencing approach to sequence and characterize the gut and genital tract microbiomes from several married Pakistani couples. The recruited individuals included 31 fertile and 35 infertile individuals, with ages ranging from 19–45 years. We identified several fluctuations in the diversity and composition of the gut and genital microbiota among fertile and infertile samples. For example, measures of α-diversity varied significantly between the genital samples donated by fertile and infertile men and there was overall greater between-sample variability in genital samples regardless of gender. In terms of taxonomic composition, Actinobacteria, Bacteroidetes, and Firmicutes fluctuated significantly between the gut microbiomes of fertile and infertile samples. Finally, biomarker analyses identified features (genera and molecular functions and pathways) that differed significantly between the fertile and infertile samples and in the past have been associated with bacterial vaginosis. However, we emphasize that 16S amplicon data alone has no bearing on individual health and is merely representative of microbial taxonomic differences that could also arise due to multiple other factors. Our findings, however, represent the first effort to characterize the microbiome associated with fertile and infertile couples in Pakistan and will hopefully pave the way for more comprehensive and broad-scale investigations in the future.

Cervical Squamous Intraepithelial Lesions Are Associated with Differences in the Vaginal Microbiota of Mexican Women

Cervical cancer is an important health concern worldwide and is one of the leading causes of death in Mexican women. Previous studies have shown changes in the female genital tract microbe community related to human papillomavirus (HPV) infection and cervical cancer; yet, this link remains unexplored in many human populations. This study evaluated the vaginal bacterial community among Mexican women with precancerous squamous intraepithelial lesions (SIL). We sequenced the V3 region of the 16S rRNA gene in cervical samples from 228 Mexican women, including 121 participants with SIL, most of which were HPV positive, and 107 healthy women without HPV infection or SIL. The presence of SIL was associated with changes in composition (beta diversity) and with a higher species richness (Chao1). A comparison of HPV-positive women with and without SIL showed that microbiota changes occurred even in the absence of SIL. Multivariate association with linear models (MaAsLin) analysis yielded independent associations between HPV infection and an increase in the relative abundance of Brachybacterium conglomeratum and Brevibacterium aureum as well as a decrease in two Lactobacillus iners operational taxonomic units (OTUs). We also identified a positive independent association between HPV-16, the most common HPV subtype linked to SIL, and Brachybacterium conglomeratum. Our work indicates that HPV infection leading to SIL is primarily associated with shifts in vaginal microbiota composition, some of which may be specific to this human population.

IMPORTANCE Human papillomavirus (HPV) plays a critical role in cervical carcinogenesis but is not sufficient for cervical cancer development, indicating the involvement of other factors. The vaginal microbiota is an important factor in controlling infections caused by HPV, and, depending on its composition, it can modulate the microenvironment in vaginal mucosa against viral infections. Ethnic and sociodemographic factors influence differences in vaginal microbiome composition, which underlies the dysbiotic patterns linked to HPV infection and cervical cancer across different populations of women. Here, we provide evidence for associations between vaginal microbiota patterns and HPV infection linked to ethnic and sociodemographic factors. To our knowledge, this is the first report of the species Brevibacterium aureum and Brachybacterium conglomeratum linked to HPV infection or squamous intraepithelial lesions (SIL).

Comprehensive Characterization of Microbial Community in the Female Genital Tract of Reproductive-Aged Women in China

The microbiota in the human body play critical roles in many physiological and pathological processes. However, the diversity and dynamics of the female genital tract (FGT) microbiota have not been fully unveiled. In this study, we characterized the microbiome variations in reproductive-aged Chinese women, and we revealed that the cervicovaginal microbiota were dominated by Lactobacillus. Overall, the composition of microbiota in the uterine cavity was more diverse than that in the vagina and cervix. A positive correlation between Lactobacillus iners and Lactobacillus crispatus was observed in both the vagina and the cervix, suggesting that these two species might have a symbiotic relationship in the cervicovaginal microbiota. Moreover, we, for the first time, stratified the reproductive-aged Chinese women into subgroups, based on their microbiome profiles. Furthermore, we identified the bacteria whose abundance changed in the uterine cavity of infertile patients when compared with healthy controls, such as L. iners and L. crispatus. Functionally, the metabolism-related pathways, neurotrophin signaling pathway, and adipocytokine signaling pathway were predominantly dysregulated in the uterine cavity of infertile patients. In conclusion, we characterized a comprehensive microbial landscape in FGT, as well as their functional roles in female infertility of the Chinese population.

Characteristics of Vaginal Microbiome in Women with Pelvic Inflammatory Disease in Korea

Human vaginal microorganisms play an important role in maintaining good health throughout the human life cycle. An imbalance in the vaginal microbiota is associated with an increased risk of pelvic inflammatory disease (PID). This study aimed to characterize and compare vaginal microbial profiles of premenopausal Korean women with and without PID. 74 Korean premenopausal female vaginal samples were obtained; 33 were from healthy women (a control group) and 41 from PID patients. Vaginal fluid samples were collected from the vaginal wall and posterior cervix and then analyzed by 16S ribosomal ribonucleic acid (rRNA) gene-based amplicon sequencing. Results showed a significant difference between the vaginal microbial communities of the two groups (Jensen-Shannon, p = 0.014; Bray-Curtis, p = 0.009; Generalized UniFrac, p = 0.007; UniFrac, p = 0.008). Lactobacillus accounted for the highest percentage (61.0%) of the control group but was significantly decreased (34.9%) in PID patients; this was the most significant difference among all bacterial communities (p = 0.028, LDA effect size = 5.129). In addition, in the PID patient group, species diversity significantly increased (Simpson, p = 0.07) as the proportion of various pathogens increased evenly, resulting in a polymicrobial infection. Similarly, lactate, which constituted the highest percentage of the organic acids in the control group, was significantly decreased in the PID patient group (p = 0.04). The present study's findings will help understand PID from the microbiome perspective and are expected to contribute to the development of more efficient PID diagnosis and treatment modalities.

Associations between bacterial vaginosis, candida vaginitis, trichomonas vaginalis, and vaginal pathogenic community in Chinese women

BACKGROUND

To investigate the associations between Vaginal Pathogenic Community with Bacterial vaginosis, Candida vaginitis, and Trichomonas vaginalis in Chinese women.

METHOD

In this experiment, ten BV, nine VVC, eight TV patients, and four non-infected healthy women were recruited. The vaginal samples were collected from the vaginal orifice, the middle of the vagina, and vaginal fornix from every participant and conducted with next-generation sequencing (NGS). The NGS was based upon the analysis of bacterial 16S rRNA genes by using the Illumina Miseq system.

RESULTS

No significant difference in microbiome community structures was observed for the three sampling sites from the same subject. Compared with the healthy population, patients with BV and TV showed more diverse symptoms and had a lower amount of Lactobacillus but a higher number of BV-related bacteria like Atopobium, Dialister, Sneathia, Mobiluncus, and Prevotella. On the contrary, the species composition of the VVC group is relatively simple, which has a significantly high abundance of Lactobacillus. Eight genera, including Arcanobacterium, Clostridium, Moryella, Mobiluncus, Shuttleworthia, Dialister, Bulleidia, and Megasphaera, were closely correlated with BV. Among vaginal pathogenic bacteria, Anaerococcus, Lysobacter, Mycoplasma, Peptoniphilus, Sneathia, and Prevotella were more common, with higher copy numbers in the TV group.

CONCLUSIONS

The data outlined the overall structure of vaginal communities, indicating that BV and TV were touching related to a sharp increase in the rich taxonomy and diversity of vaginal microbiota. VVC group presented a lower variety, with a significantly high abundance of Lactobacillus.

In silico trio-biomarkers for bacterial vaginosis revealed by species dominance network analysis

BV (bacterial vaginosis) influences 20%–40% of women but its etiology is still poorly understood. An open question about the BV is which of the hundreds of bacteria found in the human vaginal microbiome (HVM) are the major force driving the vaginal microbiota dysbiosis. Here, we recast the question of microbial causality of BV by asking if there are any prevalent ‘signatures’ (network motifs) in the vaginal microbiome networks associated with it? We apply a new framework [species dominance network analysis by Ma & Ellison (2019): Ecological Monographs) to detect critical structures in HVM networks associated with BV risks and etiology. We reanalyzed the 16 s-rRNA gene sequencing datasets of a mixed-cohort of 25 BV patients and healthy women. In these datasets, we detected 15 trio-motifs that occurred exclusively in BV patients. We failed to find any of these 15 trio-motifs in three additional cohorts of 1535 healthy women. Most member-species of the 15 trio motifs are BV-associated anaerobic bacteria (BVAB), Ravel’s community-state type indicators, or the most dominant species; virtually all species interactions in these trios are high-salience skeletons, suggesting that those trios are strongly connected ‘cults’ associated with the occurrence of BV. The presence of the trio motifs unique to BV may act as indicators for its personalized diagnosis and could help elucidate a more mechanistic interpretation of its risks and etiology. We caution that scarcity of large longitudinal datasets of HVM also limited further verifications of our findings, and these findings require further clinical tests to launch their applications.

Organoids of the female reproductive tract

Healthy functioning of the female reproductive tract (FRT) depends on balanced and dynamic regulation by hormones during the menstrual cycle, pregnancy and childbirth. The mucosal epithelial lining of different regions of the FRT-ovaries, fallopian tubes, uterus, cervix and vagina-facilitates the selective transport of gametes and successful transfer of the zygote to the uterus where it implants and pregnancy takes place. It also prevents pathogen entry. Recent developments in three-dimensional (3D) organoid systems from the FRT now provide crucial experimental models that recapitulate the cellular heterogeneity and physiological, anatomical and functional properties of the organ in vitro. In this review, we summarise the state of the art on organoids generated from different regions of the FRT. We discuss the potential applications of these powerful in vitro models to study normal physiology, fertility, infections, diseases, drug discovery and personalised medicine.

Potential Association between Vaginal Microbiota and Cervical Carcinogenesis in Korean Women: A Cohort Study

Convincing studies demonstrated that vaginal flora is one of the most impactful key components for the well-being of the genital tract in women. Nevertheless, the potential capability of vaginal-derived bacterial communities as biomarkers to monitor cervical carcinogenesis (CC) has yet to be studied actively compared to those of bacterial vaginosis (BV). We hypothesized that vaginal microbiota might be associated with the progression of CC. In this study, we enrolled 23 participants, including healthy controls (HC group; n = 7), patients with cervical intraepithelial neoplasia (CIN) 2 and 3 (CIN group, n = 8), and patients with invasive cervical cancer (CAN group; n = 8). Amplicon sequencing was performed using the Ion Torrent PGM to characterize the vaginal microbiota. Patients with CIN and CAN presented vaginal microbiota dysbiosis compared with HC. The alpha diversity analysis revealed that CC has a trend to be increased in terms of diversity indexes. Moreover, CC was associated with the abundance of specific microbes, of which Lactobacillus and Gardnerella were the most significantly different between HC and CIN, whereas Streptococcus was differentially abundant in CAN compared with CIN. We then evaluated their diagnostic abilities. Testing in terms of diagnostic ability using the three genera revealed considerably high performance with an area under the receiver-operating characteristic curve of 0.982, 0.953, and 0.922. The current study suggests that the presence of Gardnerella and Streptococcus may be involved in the advancment of CC.

Vaginal Microbiota Diversity of Patients with Embryonic Miscarriage by Using 16S rDNA High-Throughput Sequencing

Embryonic miscarriage severely affects the life quality and physical and mental state of pregnant women. However, the detailed mechanism underlying embryonic miscarriage is not fully understood. This study is aimed at analyzing embryonic miscarriage. We collected samples from 25 normal pregnant women and 25 embryonic miscarriage patients of similar age to analyze microbiota isolated from the vagina. Crude examination of the vagina isolates showed that compared with the control group, 80% of the embryonic miscarriage group contained a significantly lower number of Lactobacillus, the major healthy microbe in the vagina. Furthermore, the levels of Th1 and Th2 secreted cytokine interleukin 2 (IL-2) and interleukin10 (IL-10), respectively, were examined. Results showed that the IL2 level was higher, and IL10 level was lower in the embryonic miscarriage group than in the control group, whereas the IL2/IL10 level was higher in the embryonic miscarriage group than in the control group. This finding suggested that the immune response was suppressed in the embryonic miscarriage group. To further dissect the microbiota of the vagina in the two groups, 16S rDNA sequencing was performed. Bioinformatics analysis showed that 1096 and 998 overlapped operational taxonomic units were identified from the embryonic miscarriage and control groups, respectively. At the genus level, the relative abundance of Fam_Finegoldia, Lac_Coprococcus_3, and Lac_Roseburia significantly differed in the embryonic miscarriage group. Overall, our analyses provided potential biomarkers for embryonic miscarriage and elucidated the causative relationship between microbiota and immune responses and may enable the possible diagnosis and therapeutics of early pregnancy loss.

Microbiome diversity predicts surgical success in patients with rectovaginal fistula

INTRODUCTION AND HYPOTHESIS

Growing literature details the critical importance of the microbiome in the modulation of human health and disease including both the gastrointestinal and genitourinary systems. Rectovaginal fistulae (RVF) are notoriously difficult to manage, many requiring multiple attempts at repair before correction is achieved. RVF involves two distinct microbiome communities whose characteristics and potential interplay have not been previously characterized and may influence surgical success.

METHODS

In this pilot study, rectal and vaginal samples were collected from 14 patients with RVF. Samples were collected preoperatively, immediately following surgery, 6-8 weeks postoperatively and at the time of any fistula recurrence. Amplification of the 16S rDNA V3-V5 gene region was done to identify microbiota. Data were summarized using both α-diversity to describe species richness and evenness and β-diversity to characterize the shared variation between communities. Differential abundance analysis was performed to identify microbial taxa associated with recurrence.

RESULTS

The rectal and vaginal microbiome in patients undergoing successful fistula repair was different than in those with recurrence (β-diversity, p = 0.005 and 0.018, respectively) and was characterized by higher species diversity (α-diversity, p = 0.07 and p = 0.006, respectively). Thirty-one taxa were enriched in patients undergoing successful repair to include Bacteroidetes, Alistipes and Rikenellaceae as well as Firmicutes, Subdoligranulum, Ruminococcaceae UCG-010 and NK4A214 group.

CONCLUSIONS

Microbiome characteristics associated with fistula recurrence have been identified. The association of higher vaginal diversity with a favorable outcome has not been previously described. Expansion of this pilot project is needed to confirm findings. Taxa associated with successful repair could be targeted for subsequent therapeutic intervention.

Severe preeclampsia is associated with a higher relative abundance of Prevotella bivia in the vaginal microbiota

We sought to compare the vaginal microbiota profiles of Taiwanese women with severe preeclampsia (SPE) and normotensive control pregnancies. In a discovery cohort, vaginal swab samples and paired blood specimens were simultaneously obtained at the time of caesarean delivery from 30 women with SPE and 30 controls. The composition of vaginal microbiota was characterised by 16S ribosomal RNA gene sequencing of the V3–V4 region. Results were subsequently validated by real-time qPCR. We sought confirmation of our findings in an expanded cohort consisting of 58 women with SPE and 55 controls. In both the discovery and confirmation cohorts, women with SPE had higher relative abundance of Prevotella bivia in their vaginal microbial community (P = 0.006 and 0.011, respectively). Plasma levels of tumour necrosis factor alpha (TNF-α) were higher when compared with controls (P = 0.031) in the confirmation cohort. Three variables (vaginal Prevotella bivia, plasma TNF-α, and body mass index [BMI]) were included in a prediction panel for SPE. Of these, BMI was the most predictive variable. The area under the curve (AUC) of predicted probability values for the three-variable panel revealed that it can discriminate between SPE and normotensive pregnancies with good accuracy (AUC = 0.797, P < 0.001). We conclude that enrichment of Prevotella bivia in vaginal microbiota, which is tightly regulated by BMI, may be involved in the pathogenesis of SPE.

The effect of probiotic supplementation during pregnancy on the interaction network of vaginal microbiome

AIM

To evaluate the effect of probiotic supplementation on the vaginal microbiome and provide the effective evidences for clinical management of pregnant women.

METHODS

A total of 28 healthy pregnant women at 32 weeks of gestation were enrolled. The women were divided randomly to the probiotic group where they were prescribed with 2 g combined probiotics daily (13 cases) during the third trimester of pregnancy or to the control group (15 cases) on a voluntary basis. Their vaginal samples were taken for analyzing microbiome with the 16S rDNA amplicon sequencing of V4 region.

RESULTS

There was no significant difference on the clinical characteristics between the probiotic and control groups. The complexity of vaginal microbial network increased from 32 weeks of gestation to antepartum. Lactobacillus was the dominant microbiota. The probiotic supplementation had no obvious influence on the structure of the vaginal microbiome, whereas the relationships of some pivotal vaginal microbiota at the genus level changed in the probiotic group.

CONCLUSION

The vaginal microbiome varied during the third trimester of pregnancy. The features of the vaginal microbiota after probiotic supplementation had shifted and the interaction network had the tendency to be loose. The probiotic supplementation may be useful in regulating the interaction network of vaginal microbiome.

The vaginal microbiome of sub-Saharan African women: revealing important gaps in the era of next-generation sequencing

Accurate characterization of the vaginal microbiome remains a fundamental goal of the Human Microbiome project (HMP). For over a decade, this goal has been made possible deploying high-throughput next generation sequencing technologies (NGS), which indeed has revolutionized medical research and enabled large-scale genomic studies. The 16S rRNA marker-gene survey is the most commonly explored approach for vaginal microbial community studies. With this approach, prior studies have elucidated substantial variations in the vaginal microbiome of women from different ethnicities. This review provides a comprehensive account of studies that have deployed this approach to describe the vaginal microbiota of African women in health and disease. On the basis of published data, the few studies reported from the African population are mainly in non-pregnant post pubertal women and calls for more detailed studies in pregnant and postnatal cohorts. We provide insight on the use of more sophisticated cutting-edge technologies in characterizing the vaginal microbiome. These technologies offer high-resolution detection of vaginal microbiome variations and community functional capabilities, which can shed light into several discrepancies observed in the vaginal microbiota of African women in an African population versus women of African descent in the diaspora.

Characterization of the Vaginal Microbiome in Women with Infertility and Its Potential Correlation with Hormone Stimulation during In Vitro Fertilization Surgery

The microbiome had been hypothesized to be involved in the physiology and pathophysiology of assisted reproduction before the first success in IVF, while the data supporting or refuting this hypothesis were less than conclusive. Thanks to sequencing data from the 16S rRNA subunit, we characterized the microbiome in the reproductive tract of infertile women, and we found that changes in the vaginal microbiome are related to female infertility. We also found that the characteristic microbiome bacteria are mainly members of several genera and that the vaginal microbiome of infertile women is not sensitive to hormonal changes during IVF. In conclusion, our report provides data that can be used for discovering the role of the vaginal microbiome in patients suffering from secondary infertility.

Perturbation of vaginal microbiome of reproductive-age women influences all the phases of a woman's reproductive life. Although studies have shown that dynamic changes in vaginal microbiome can affect pregnancy, its role in secondary infertility (i.e., inability to become pregnant or to carry a pregnancy successfully after previous success in delivering a child) and in vitrofertilization (IVF) remains to be unraveled. To determine the vaginal microbiome in women undergoing in vitrofertilization and embryo transfer (IVF-ET) and investigate its potential correlations with hormone stimulation, we recruited 30 patients with secondary infertility and receiving IVF and 92 matched healthy women and analyzed their vaginal microbiome composition using 16S rRNA gene sequencing. Our results show that women suffering from infertility (infertile women) exhibit a significant decrease in microbiome diversity and richness compared with healthy women during the nonovulation period (follicular phase) (P < 0.01), whereas vaginal microbiome of healthy women reveals dramatic fluctuations during ovulation (P < 0.05). Interestingly, infertility patients show no change of the vaginal microbiome under conditions of gonadotropin-releasing hormone (GnRH) agonist and recombinant human chorionic gonadotropin (r-hCG) induction (P > 0.05). Moreover, our results indicate that infertile women show characteristic variations in vaginal microbiome, such as increased abundance of Atopobium, Aerococcus, and Bifidobacterium and decreased abundance of Lactobacillus and Leuconostoc.

IMPORTANCE The microbiome had been hypothesized to be involved in the physiology and pathophysiology of assisted reproduction before the first success in IVF, while the data supporting or refuting this hypothesis were less than conclusive. Thanks to sequencing data from the 16S rRNA subunit, we characterized the microbiome in the reproductive tract of infertile women, and we found that changes in the vaginal microbiome are related to female infertility. We also found that the characteristic microbiome bacteria are mainly members of several genera and that the vaginal microbiome of infertile women is not sensitive to hormonal changes during IVF. In conclusion, our report provides data that can be used for discovering the role of the vaginal microbiome in patients suffering from secondary infertility.

Vulvar pruritus-Causes, Diagnosis and Therapeutic Approach

BACKGROUND

In Germany, 17-23% of the population suffers from chronic itching of the skin; in 5-10% of cases, the female genitalia are affected, specifically, the vulva. Vulvar pruritus is thus a common symptom that often markedly impairs the affected women's quality of life.

METHODS

This review is based on pertinent publications that were retrieved by a selective search in MEDLINE/PubMed for articles on the pathogenesis, diagnosis, and treatment of vul- var pruritus. The search terms were (in German and English) "vulvärer Juckreiz," "pruritus vulvae," and "genital itch," alone and in combination with "Behandlung," "Therapie," or "treat- ment."

RESULTS

The most common cause of vulvar pruritus is vulvo- vaginal candidiasis followed by chronic dermatoses, such as lichen sclerosus and vulvar eczema. Especially in refractory cases, an invasive or preinvasive lesion such as squamous epithelial dysplasia (VIN, vulvar intraepithelial neoplasia) should be borne in mind in the differential diagnosis. Rarer causes include infection, atrophy, and vulvodynia. The essen- tial elements of treatment are topical/oral antimycotic drugs and high-potency glucocorticoids, along with consistently ap- plied, basic moisturizing care and the avoidance of potential triggering factors.

CONCLUSION

As vulvar pruritus has multiple causes, standard- ization of its diagnostic evaluation and treatment would be l efficacy and to meet the diverse needs of women who suffer from this condition.

The vaginal sheet: an innovative form of vaginal film for the treatment of vaginal infections

Objective: To develop and characterize a new form of vaginal film.Significance: This formulation is intended to overcome some known limitations of traditional dosage forms. It has an absorptive intention to control symptoms and to improve the treatment of vaginal infections characterized by excessive fluid. The vaginal sheet is a thick drug delivery system easy to manipulate, nontoxic and composed by biocompatible macromolecules and polymers, such as gelatin and chitosan.Methods: The sheets were prepared by formulating gelatin or chitosan based gels isolated or in combination, in association with a plasticizer. Gels were subsequently lyophilized. Different proportions of polymer:plasticizer were tested. Lactose was used as a surrogate to study powder incorporation in the formulation. All formulations were analyzed regarding their organoleptic characteristics, texture (hardness and resilience), in vitro absorption efficiency of vaginal fluid simulant - VFS (pH 4 and 5), pH and acid-buffering capacity.Results: Different properties were obtained by varying polymer and plasticizer proportions. Combinations including gelatin with propylene glycol showed the best organoleptic characteristics. The best proportions were 4:3 and 4:5. Up to 10% of powder was successfully incorporated in the formulation. Hardness and resilience of formulations were largely dependent on the concentration of plasticizer. Absorption of vaginal fluid was found to be highly efficient, especially at pH 5. Buffering capacity, upon dilution in normal saline and VFS, was generally higher for VFS pH 4.Conclusions: The vaginal sheet is a promising solid drug delivery system able to further incorporate drugs to treat vaginal clinical conditions characterized by excessive fluid.

A population-based study of age-related associations between vaginal pH and the development of cervical intraepithelial neoplasia

The association between vaginal pH and the risk of cervical intraepithelial neoplasia (CIN) is unclear. We evaluated the dose‐response relationship between vaginal pH and CIN risk, as well as the combined influence of vaginal pH and high‐risk human papillomavirus (hrHPV) on the risk of CIN and the mediation effects of hrHPV infection on vaginal pH level and the development of CIN. We investigated 2304 women in Shanxi, China. The dose‐response relationship between vaginal pH and CIN risk was assessed using categoric and spline analyses. We established interaction and mediation models to determine the correlation between pH and hrHPV in the development of CIN. After adjusting covariates, a positive association was observed between hrHPV infection and the development of CIN [OR (95% CI) = 4.75 (3.52‐6.40) for CIN2+; OR (95% CI) = 7.30 (4.10‐13.00) for CIN3+], while a negative correlation was showed between vaginal pH level and CIN3+ [OR (95% CI) = 1.04 (0.59‐1.84); high vs low: OR (95% CI) = 0.32 (0.15‐0.69), P = .002]. The highest risk of CIN (5.24 of CIN2+ and 5.80 of CIN3+) were observed when hrHPV infection was combined with middle vaginal pH (4.6‐5.0). A significant mediation effect of hrHPV infection was observed in the association between vaginal pH level with CIN2+ (P = .002) and CIN3+ (P = .004). In conclusion, abnormal vaginal pH significantly induced the risk of high‐stage CIN in Chinese women infected with hrHPV. Therefore, maintaining normal vaginal pH levels may reduce the risk of CIN.

The Role of the Cervicovaginal Microbiome on the Genesis and as a Biomarker of Premalignant Cervical Intraepithelial Neoplasia and Invasive Cervical Cancer

The microbiome is able to modulate immune responses, alter the physiology of the human organism, and increase the risk of viral infections and development of diseases such as cancer. In this review, we address changes in the cervical microbiota as potential biomarkers to identify the risk of cervical intraepithelial neoplasia (CIN) development and invasive cervical cancer in the context of human papillomavirus (HPV) infection. Current approaches for clinical diagnostics and the manipulation of microbiota with the use of probiotics and through microbiota transplantation are also discussed.

Diversity of vaginal microbiome and metabolome during genital infections

We characterized the vaginal ecosystem during common infections of the female genital tract, as vulvovaginal candidiasis (VVC, n = 18) and Chlamydia trachomatis infection (CT, n = 20), recruiting healthy (HC, n = 21) and bacterial vaginosis-affected (BV, n = 20) women as references of eubiosis and dysbiosis. The profiles of the vaginal microbiome and metabolome were studied in 79 reproductive-aged women, by means of next generation sequencing and proton based-nuclear magnetic resonance spectroscopy. Lactobacillus genus was profoundly depleted in all the genital infections herein considered, and species-level analysis revealed that healthy vaginal microbiome was dominated by L. crispatus. In the shift from HC to CT, VVC, and BV, L. crispatus was progressively replaced by L. iners. CT infection and VVC, as well as BV condition, were mainly characterised by anaerobe genera, e.g. Gardnerella, Prevotella, Megasphaera, Roseburia and Atopobium. The changes in the bacterial communities occurring during the genital infections resulted in significant alterations in the vaginal metabolites composition, being the decrease of lactate a common marker of all the pathological conditions. In conclusion, according to the taxonomic and metabolomics analysis, we found that each of the four conditions is characterized by a peculiar vaginal microbiome/metabolome fingerprint.

Curcumin solid dispersion-loaded in situ hydrogels for local treatment of injured vaginal bacterial infection and improvement of vaginal wound healing

OBJECTIVES

Injured vaginal infection is detrimental to women. A curcumin hydrogel was studied for local treatment of injured vaginal infection.

METHODS

Curcumin solid dispersions (CSDs) were prepared from polyvinyl pyrrolidone and characterized by differential scanning calorimetry and an X-ray diffraction method. An in situ hydrogel CSD hydrogel (CSDG) was prepared with CSD/poloxamers and characterized. In vitro curcumin release and antibacterial effects of CSDs, CSDGs and curcumin were compared. The therapeutic effect of the CSDGs and Lincomycin/Lidocaine Gel was explored after intravaginal administration on the injured rat vaginal infection models.

KEY FINDINGS

Curcumin was amorphous in CSDs where curcumin rapidly released in simulated vaginal fluids. However, CSDGs showed sustained release. CSDGs quickly formed gels in the vagina. CSDGs showed high in vivo anti-Escherichia coli or Staphylococcus aureus effect though weak in vitro effect. The recovery of vaginal microenvironment and improvement of intravaginal Lactobacillus growth may be the major reason. Furthermore, CSDGs remarkably improved vaginal wound healing by alleviating inflammation and restoring vaginal epidermal tissues compared with the Lincomycin/Lidocaine Gel.

CONCLUSION

CSDGs are a promising topical formulation for local treatment of vaginal bacterial infection and improvement of vaginal wound healing.

Evaluating the potential of residual Pap test fluid as a resource for the metaproteomic analysis of the cervical-vaginal microbiome

The human cervical-vaginal area contains proteins derived from microorganisms that may prevent or predispose women to gynecological conditions. The liquid Pap test fixative is an unexplored resource for analysis of microbial communities and the microbe-host interaction. Previously, we showed that the residual cell-free fixative from discarded Pap tests of healthy women could be used for mass spectrometry (MS) based proteomic identification of cervical-vaginal proteins. In this study, we reprocessed these MS raw data files for metaproteomic analysis to characterize the microbial community composition and function of microbial proteins in the cervical-vaginal region. This was accomplished by developing a customized protein sequence database encompassing microbes likely present in the vagina. High-mass accuracy data were searched against the protein FASTA database using a two-step search method within the Galaxy for proteomics platform. Data was analyzed by MEGAN6 (MetaGenomeAnalyzer) for phylogenetic and functional characterization. We identified over 300 unique peptides from a variety of bacterial phyla and Candida. Peptides corresponding to proteins involved in carbohydrate metabolism, oxidation-reduction, and transport were identified. By identifying microbial peptides in Pap test supernatants it may be possible to acquire a functional signature of these microbes, as well as detect specific proteins associated with cervical health and disease.

Systematic Bias Introduced by Genomic DNA Template Dilution in 16S rRNA Gene-Targeted Microbiota Profiling in Human Stool Homogenates

The genomic DNA input for stool samples utilized for microbiome composition has not been determined. In this study, we determined the reliable threshold level under which conclusions drawn from the data may be compromised. We also determined the type of microbial bias introduced by less-than-ideal genomic input.

Variability in representation of microbial communities can be caused by differences in microbial composition or artifacts introduced at sample collection or processing. Alterations in community representation introduced by variations in starting DNA concentrations have not been systematically investigated in stool samples. The goal of this study was to evaluate the effect of the genomic DNA (gDNA) concentration in the resulting 16S rRNA gene library composition and compare its effect to other sample processing variables in homogenized human fecal material. Compared to a gDNA input of 1 ng/μl, inputs of ≤1.6 × 10⁻³ ng/μl resulted in a marked decrease in the concentration of the 16S rRNA gene amplicon (P < 0.001). Low gDNA concentrations (≤1.6 × 10⁻³ ng/μl) were also associated with a decrease (P < 0.001) in the number of operational taxonomic units and significant divergence in β-diversity profiles (unweighted UniFrac distance, P < 0.001), as characterized by an overestimation of Proteobacteria and underestimation of Firmicutes. Even a gDNA concentration of 4 × 10⁻² ng/μl showed a significant impact on the β-diversity profile (unweighted UniFrac distance, P = 0.03). Overall, the gDNA concentration explained 22.4% to 38.1% of the microbiota variation based on various β-diversity measures (P < 0.001). By comparison, the DNA extraction methods and PCR volumes tested did not significantly affect the microbial composition profile, and the PCR cycling method explained less than 3.7% of the microbiota variation (weighted UniFrac distance, P = 0.03). The 16S rRNA gene yield and the microbial community representation of human homogenized stool samples are significantly altered by gDNA template concentrations of ≤1.6 × 10⁻³ ng/μl. In addition, data from studies with a gDNA input of ≤4 × 10⁻² ng/μl should be interpreted with caution.

IMPORTANCE The genomic DNA input for stool samples utilized for microbiome composition has not been determined. In this study, we determined the reliable threshold level under which conclusions drawn from the data may be compromised. We also determined the type of microbial bias introduced by less-than-ideal genomic input.

Dysbiosis of the Vaginal Microbiota and Higher Vaginal Kynurenine/Tryptophan Ratio Reveals an Association with Chlamydia trachomatis Genital Infections

The natural course of Chlamydia trachomatis urogenital tract infections varies between individuals. While protective immunity can occur, some women can become reinfected, contributing to the development of severe pathology. While the reasons for these differences are unknown, an individual's response to induced interferon-γ (IFN-γ) is suggested to be critical. IFN-γ induction of the enzyme indoleamine 2,3-dioxygenase, which depletes tryptophan, may be the key. One hypothesis suggests that indole-producing bacteria in the vaginal microbiota can provide a substrate for the Chlamydia to synthesize tryptophan, rescuing the Chlamydia from host IFN-γ attack. We studied a cohort of 25 women who were either, Chlamydia negative, Chlamydia positive with a single infection, or Chlamydia positive with repeated infection, to test our hypothesis. We characterized their vaginal microbiota, cytokine response, as well as their tryptophan, kynurenine and indole concentrations directly in vaginal secretions. We found that C. trachomatis urogenital tract infections either initial or repeat infections, were associated with elevated vaginal kynurenine/tryptophan ratios, primarily as a result of elevated kynurenine levels. In addition, vaginal microbiota of community state type (CST) IV showed significantly lower vaginal tryptophan levels compared to CST I and III, which might be related to a higher abundance of indole producers found within this group. Furthermore, we found a higher abundance of indole producers in women who cleared their Chlamydia infection post antibiotic treatment. This study demonstrates for the first time in vivo, the association between high vaginal kynurenine/tryptophan ratios and C. trachomatis infections. In addition, tryptophan depletion was associated with vaginal microbiota of CST IV.

Inheritance and Establishment of Gut Microbiota in Chickens

In mammals, the microbiota can be transmitted from the placenta, uterus, and vagina of the mother to the infant. Unlike mammals, development of the avian embryo is a process isolated from the mother and thus in the avian embryo the gut microbial developmental process remains elusive. To explore the establishment and inheritance of the gut microbiome in the avian embryo, we used the chicken as the model organism to investigate the gut microbial composition in embryos, chicks, and maternal hens. We observed: (1) 28 phyla and 162 genera of microbes in embryos where the dominated genus was Halomonas (79%). (2) 65 genera were core microbiota in all stages with 42% and 62% gut microbial genera of embryo were found in maternal hen and chick, respectively. There was a moderate correlation (0.40) between the embryo and maternal, and 0.52 between the embryo and chick at the family level. (3) Gut microbes that are involved in substance metabolism, infectious disease, and environmental adaptation are enriched in embryos, chicks, and maternal hens, respectively. (4) 94% genera of gut microbial composition were similar among three different chicken breeds which were maintained under similar conditions. Our findings provide evidence to support the hypothesis that part of the microbial colonizers harbored in early embryos were inherited from maternal hens, and the gut microbial abundance and diversity were influenced by environmental factors and host genetic variation during development.

Effects of microbial DNA on human DNA profiles generated using the PowerPlex® 16 HS system

Most crime scenes are not sterile and therefore may be contaminated with environmental DNA, especially if a decomposing body is found. Collecting biological evidence from this individual will yield DNA samples mixed with microbial DNA. This also becomes important if postmortem swabs are collected from sexually assaulted victims. Although genotyping kits undergo validation tests, including bacterial screens, they do not account for the diverse microbial load during decomposition. We investigated the effect of spiking human DNA samples with known concentrations of DNA from 17 microbe species associated with decomposition on DNA profiles produced using the Promega PowerPlex^® HS system. Two species, Bacillus subtilis and Mycobacterium smegmatis, produced an extraneous allele at the TPOX locus. When repeated with the PowerPlex^® Fusion kit, the extra allele no longer amplified with these two species. This experiment demonstrates that caution should be exhibited if microbial load is high and the PowerPlex^® 16HS system is used.

Ovarian cycling and reproductive state shape the vaginal microbiota in wild baboons

BACKGROUND

The vaginal microbiome is an important site of bacterial-mammalian symbiosis. This symbiosis is currently best characterized for humans, where lactobacilli dominate the microbial community and may help defend women against infectious disease. However, lactobacilli do not dominate the vaginal microbiota of any other mammal studied to date, raising key questions about the forces that shape the vaginal microbiome in non-human mammals.

RESULTS

We used Illumina sequencing of the bacterial 16S rRNA gene to investigate variation in the taxonomic composition of the vaginal microbiota in 48 baboons (Papio cynocephalus), members of a well-studied wild population in Kenya. Similar to prior studies, we found that the baboon vaginal microbiota was not dominated by lactobacilli. Despite this difference, and similar to humans, reproductive state was the dominant predictor of baboon vaginal microbiota, with pregnancy, postpartum amenorrhea, and ovarian cycling explaining 18% of the variance in community composition. Furthermore, among cycling females, a striking 39% of variance in community composition was explained by ovarian cycle phase, with an especially distinctive microbial community around ovulation. Periovulatory females exhibited the highest relative abundance of lactic acid-producing bacteria compared to any other phase, with a mean relative abundance of 44%. To a lesser extent, sexual behavior, especially a history of shared sexual partners, also predicted vaginal microbial similarity between baboons.

CONCLUSIONS

Despite striking differences in their dominant microbes, both human and baboon vaginal microbiota exhibit profound changes in composition in response to reproductive state, ovarian cycle phase, and sexual behavior. We found major shifts in composition during ovulation, which may have implications for disease risk and conception success. These findings highlight the need for future studies to account for fine-scale differences in reproductive state, particularly differences between the various phases of the ovarian cycle. Overall, our work contributes to an emerging understanding of the forces that explain intra- and inter-individual variation in the mammalian vaginal microbiome, with particular emphasis on its role in host health and disease risk.

The microbiome during pregnancy and early postnatal life

We are changing our concept that the newborn infant emerges from a sterile environment. In-utero colonization may have major impacts on the developing mammal in terms of development of immunity and metabolism that, with epigenetic modifications, will lead to diseases in later life. In addition, the microbial profile that develops during and after birth depends on mode of delivery, type of feeding (human milk versus formula) and various other environmental factors to which the newborn is exposed. The goal of this review is to clarify that the microbiome in the maternal fetal unit as well as the immediate changes that occur as new microbes are acquired postnatally play major roles in subsequent health and disease. Rapidly developing technologies for multi-omic analyses and systems biology are shifting paradigms in both scientific knowledge and clinical care.