Reproductive Tract Microbiome Research Articles

Comparative analysis of reproductive tract microbiomes in modern and slower-growing broiler breeder lines.

The reproductive tract microbiome in hens is of interest because bacteria in the reproductive tract could potentially affect fertilization and egg production, as well as integrate into the forming egg and vertically transmit to progeny. The reproductive tract microbiome of 37-week-old modern commercial Cobb breeding dams was compared with that of dams from a broiler Legacy line which has not undergone selection since 1986. All animals were kept together under the same management protocol from day of hatch to avoid confounders. In regards to reproductive abilities, Cobb dams' eggs weighed more and the magnum section of their reproductive tract was longer. In regards to microbiome composition, it was found that the reproductive tract microbiomes of the two lines had a lot in common but also that the two breeds have unique reproductive tract microbiomes. Specifically, the order Pseudomonadales was higher in the magnum of Legacy dams, while Verrucomicrobiales was lower. In the infundibulum, Lactobacillales were higher in the Legacy dams while Verrucomicrobiales, Bacteroidales, RF32 and YS2 were lower. our results show that breeding programs have modified not only the physiology of the reproductive tract but also the reproductive tract microbiome. Additional research is required to understand the implications of these changes in the reproductive tract microbiome on the chicken host.

Microbiome in gynecologic malignancies: a bibliometric analysis from 2012 to 2022.

Microbiome and microbial dysbiosis have been proven to be involved in the carcinogenesis and treatment of gynecologic malignancies. However, there is a noticeable gap in the literature, as no comprehensive papers have covered general information, research status, and research frontiers in this field. This study addressed this gap by exploring the relationship between the gut and female reproductive tract (FRT) microbiome and gynecological cancers from a bibliometric perspective. Using VOSviewer 1.6.18, CiteSpace 6.1.R6, and HistCite Pro 2.1 software, we analyzed data retrieved from the Web of Science (WOS) Core Collection (WoSCC) database. Our dataset, consisting of 204 articles published from 2012 to 2022, revealed a consistent and upward publication trend. The United States and the United Kingdom were the primary driving forces, attributed to their prolificacy, high-quality output, and extensive cooperation. The University of Arizona Cancer Center, which is affiliated with the United States, ranked first among the top ten most prolific institutions. Frontiers in Cellular and Infection Microbiology emerged as the leading publisher. Herbst-Kralovetz MM led as the most productive author. Mitra A was the most influential author. Cervical cancer is notably associated with the microbiome, while endometrial and ovarian cancers are receiving increased attention in the last year. Intersections between the gut microbiome and estrogen are of growing importance. Current research focuses on identifying specific microbial species for etiological diagnosis, while frontiers mainly focus on the anticancer potential of microorganisms, such as regulating the effects of immune checkpoint inhibitors. In conclusion, this study sheds light on a novel and burgeoning direction of research, providing a one-stop overview of the microbiome in gynecologic malignancies. Its findings aim to help young researchers to identify research directions and future trends for ongoing investigations.

Deciphering the role of female reproductive tract microbiome in reproductive health: a review.

Relevant studies increasingly indicate that female reproductive health is confronted with substantial challenges. Emerging research has revealed that the microbiome interacts with the anatomy, histology, and immunity of the female reproductive tract, which are the cornerstone of maintaining female reproductive health and preventing adverse pregnancy outcomes. Currently, the precise mechanisms underlying their interaction and impact on physiological functions of the reproductive tract remain elusive, constituting a prominent area of investigation within the field of female reproductive tract microecology. From this new perspective, we explore the mechanisms of interactions between the microbiome and the anatomy, histology, and immunity of the female reproductive tract, factors that affect the composition of the microbiome in the female reproductive tract, as well as personalized medicine approaches in managing female reproductive tract health based on the microbiome. This study highlights the pivotal role of the female reproductive tract microbiome in maintaining reproductive health and influencing the occurrence of reproductive tract diseases. These findings support the exploration of innovative approaches for the prevention, monitoring and treatment of female reproductive tract diseases based on the microbiome.

Effect of environmental factors on seminal microbiome and impact on sperm quality.

This review provides a comprehensive overview of the existing research on the seminal microbiome and its association with male infertility, while also highlighting areas that warrant further investigation. A narrative review was conducted, encompassing all relevant studies published between 1980-2023 on the male reproductive tract microbiome in humans. This review considered studies utilizing culture-based, polymerase chain reaction (PCR)-based, and next-generation sequencing (NGS)-based methodologies to analyze the microbiome. Data extraction encompassed sample types (semen or testicular tissue), study designs, participant characteristics, employed techniques, and critical findings. We included 37 studies comprising 9,310 participants. Among these, 16 studies used culture-based methods, 16 utilized NGS, and five employed a combination of methods for microorganism identification. Notably, none of the studies assessed fungi or viruses. All NGS-based studies identified the presence of bacteria in all semen samples. Two notable characteristics of the seminal microbiome were observed: substantial variability in species composition among individuals and the formation of microbial communities with a dominant species. Studies examining the testicular microbiome revealed that the testicular compartment is not sterile. Interestingly, sexually active couples shared 56% of predominant genera, and among couples with positive cultures in both partners, 61% of them shared at least one genital pathogen. In couples with infertility of known causes, there was an overlap in bacterial composition between the seminal and vaginal microbiomes, featuring an increased prevalence of Staphylococcus and Streptococcus genera. Furthermore, the seminal microbiome had discernible effects on reproductive outcomes. However, bacteria in IVF culture media did not seem to impact pregnancy rates. Existing literature underscores that various genera of bacteria colonize the male reproductive tract. These organisms do not exist independently; instead, they play a pivotal role in regulating functions and maintaining hemostasis. Future research should prioritize longitudinal and prospective studies and investigations into the influence of infertility causes and commonly prescribed medication to enhance our understanding of the seminal microbiota's role in reproductive health.

PSI-12 Characterization of Boar Reproductive Tract Microbiome Prior to Puberty Attainment

Abstract A large portion of microbiome research has focused on characterization of the gastrointestinal tract and female reproductive tract. However, minimal research has focused on establishing the bacterial community in other organs, specifically male reproductive tissues and gonads. Characterization of these microbiomes in early life could be an indicator of future semen microbiome composition and subsequent fertility status. The aim of this study was to characterize the bacterial communities of various male reproductive tissues including the testes, epididymis, seminal vesicles, prostate, bulbourethral glands, and preputial diverticulum in pre-pubertal boars. Crossbred boars (n = 4), fed a conventional diet (20% crude protein), were euthanized at approximately 2 months of age, and their intact reproductive tracts were removed. For each tissue (testes, epididymis, seminal vesicles, prostate, bulbourethral glands, and preputial diverticulum), a small incision was made before a sterile swab was rotated several times and placed into a sterile microcentrifuge tube for further analysis. A sterile swab was exposed to the environment and placed into a sterile microcentrifuge tube to act as a negative control. Samples were stored at -80°C before microbiome sequencing targeting the V4 hypervariable region of the 16S rRNA bacterial gene. Statistical analysis was conducted using the PROC GLM procedure in SAS 9.4. A greater relative abundance of the phylum Firmicutes was observed in the preputial diverticulum than the bulbourethral glands, seminal vesicles, and prostate (75.1 ± 3.6% vs. 62.3 ± 3.1%, 59.3 ± 3.1%, 58.4 ± 3.1%, respectively; P < 0.05). Within Firmicutes, the relative abundance of the genus Blautia was reduced in the preputial diverticulum compared with testes, epididymis, seminal vesicles, bulbourethral glands, and prostate (0.6 ± 1.5% vs. 8.1 ± 1.3%, 8.1 ± 1.3%, 8.1 ± 1.3%, 7.6 ± 1.3%, 7.4 ± 1.3%, respectively; P < 0.01). In contrast, the genus Peptoniphilus, under the phylum Firmicutes, was more abundant in the preputial diverticulum than the testes, epididymis, seminal vesicles, bulbourethral glands, and prostate (8.8 ± 1.5% vs. 0.3 ± 1.3%, 0.1 ± 1.3%, 0.2 ± 1.3%, 0.1 ± 1.3%, 0.2 ± 1.3%, respectively; P < 0.01). The relative abundance of the phylum Bacteroidetes within the testes had a decreased relative abundance in comparison to the bulbourethral glands (14.2% vs. 23.6 ± 2.5%; P = 0.01), prostate (14.2% vs. 27.0 ± 2.5%; P = 0.01), and seminal vesicles (14.2% vs. 30.1 ± 2.5%; P = 0.01). The seminal vesicles (6.5% vs. 2.9 ± 0.8%; P < 0.01) and prostate (5.4% vs. 2.9 ± 0.8%; P < 0.05) had a greater relative abundance of the genus Bacteroides, within the phylum Bacteroidetes, than the testes. A greater relative abundance of the phylum Proteobacteria was observed in the preputial diverticulum than the bulbourethral gland, prostate, seminal vesicles, testes, and epididymis (13.5 ± 1.7% vs. 6.3 ± 1.5%, 6.5 ± 1.5%, 5.8 ± 1.5%, 5.6 ± 1.5%, 5.5 ± 1.5%, respectively; P < 0.01). Based on these results, it appears the preputial diverticulum and the testes have distinct bacterial communities that differ from the male accessory sex glands including the prostate, bulbourethral glands, and seminal vesicles. Further research is needed to characterize the boar reproductive tract microbiome and determine its relationship with fertility.

An updated view on the role of the female reproductive tract microbiome in IVF outcomes

Introduction. In the last decade, a high-throughput 16S ribosomal RNA (rRNA) sequencing allowed to markedly extend insights into female reproductive tract microbiome. However, evidence about its role on in vitro fertilization (IVF) outcomes remains scarce and controversial.Aim: to analyze literature data for assessing an impact of the vaginal, uterine, and ovarian microbiome on IVF outcomes.Materials and Methods. The review was carried out based on publications from available in PubMed/MEDLINE, EBSCO, ResearchGate, Google Academy and еLibrary databases released over the last 20 years. For this, there was search for keywords and their combinations in Russian- and English-written publications: «vaginal microbiome», «cervical microbiome», «uterine microbiome», «ovarian microbiome», «microbiome of ovarian follicles», «IVF», «miscarriage», «early pregnancy loss», «implantation failure», «ovarian failure», «inflammasome». Only full-text original articles and reviews published in peer-reviewed journals were included in the review. Exclusion criteria were as follows: studies containing less than 10 observations per group, abstracts of conferences, studies on the male reproductive tract microbiome. Duplicate publicationswere excluded. The publications were selected independently by two co-authors, and in case of discrepancy two other co-authors were involved.Results. Vaginal, uterine, and ovarian microbiomes were characterized by providing relevant classifications and the features related to implantation failures and pregnancy loss after IVF. It was found that a decline in total Lactobacillus level and elevated proportion of L. jensenii, G. vaginalis, and Proteobacteria in the vaginal microbiome were predictors of implantation failure. In addition, IVF failure was also associated with the presence of Atopobium, Bifidobacterium, Chryseobacterium, Gardnerella, Streptococcus, Haemophilus, Staphylococcus, Brevundimonas, and Ralstonia in the uterine cavity as well as Bifidobacterium, Gardnerella, and Klebsiella in the endometrial tissue. On the other hand, Lactobacillus dominance in the uterine microbiome has a favorable effect. The colonization of the follicle by any microorganisms as well as the presence of follicular fluid anaerobic bacteria-derived metabolite trimethylamine-N-oxide (TMAO) associated with bacterial vaginosis additionally alters IVF outcomes. Moreover, the role of infectious cues in lowered ovarian reserve has also been established. Activation of the NLRP3 (NLR Family Pyrin Domain Containing 3) inflammasome by microbe-derived ligands stimulates production of pro-inflammatory cytokines and contributes to reduced follicle number. Blocking NLRP3 in mouse experiments can delay depletion of the follicle pool and result in elevated fertility.Conclusion. Favorable IVF outcomes are associated with Lactobacillus predominance in the vaginal and endometrial microbiome as well as lack of follicular fluid microorganisms. TMAO detected in the follicular fluid as well as activated NLRP3 inflammasome serve as negative predictors of IVF outcomes.

Gut and reproductive tract microbiota: Insights into the pathogenesis of endometriosis (Review).

Endometriosis is characterized by the presence of endometrial-like tissue outside the uterus and is associated with an inflammatory immune response. The gut and reproductive tract microbiota constitute a protective barrier against infection by pathogens and regulate inflammatory and immune functions. This review summarizes microbiota imbalance (i.e., dysbiosis) in endometriosis and discusses how dysbiosis influences disease development. The literature was searched for studies published from inception to March 2022 in the PubMed and Google Scholar databases using a combination of specific terms. An altered gut and reproductive tract microbiome has been reported in numerous conditions, such as inflammatory bowel disease, allergies, autoimmunity, cancer and reproductive disorders (e.g., endometriosis). Furthermore, microbial dysbiosis is a hallmark of endometriosis and is characterized by a decrease in beneficial probiotics and an increase in pathogenic microbes, which leads to a series of estrobolomic and metabolomic changes. Gut or reproductive tract microbiome dysbiosis was reported in mice, nonhuman primates, and females with endometriosis. Animal models of endometriosis demonstrated the effects of the gut microbiome on lesion growth and vice versa. The immune system mediated by the microbiota-gut-reproductive tract axis triggers an inflammatory response that damages reproductive tract tissue, which possibly leads to endometriosis. However, whether the alteration of eubiosis (a balanced microbiota) to dysbiosis is a cause or a result of endometriosis is unclear. In conclusion, this review provides an overview of the relationship between the gut and reproductive tract microbiome and endometriosis, focusing on the mechanisms by which dysbiosis may increase the risk of disease.

Lactobacillus crispatus-dominated vaginal microbiome and Acinetobacter-dominated seminal microbiome support beneficial ART outcome.

Despite the considerable progress made in assisted reproductive technologies (ART), the implantation rate of transferred embryos remains low and in many cases, the reasons for failure remain unclear. We aimed to determine the potential impact of female and male partners' reproductive tract microbiome composition on ART outcome. The ART couples (n = 97) and healthy couples (n = 12) were recruited into the study. The smaller healthy group underwent a careful selection according to their reproductive and general health criteria. Both vaginal and semen samples were subjected to 16S rDNA sequencing to reveal the bacterial diversity and identify distinct microbial community types. Ethics statement The study was approved by the Ethics Review Committee on Human Research of Tartu University, Tartu, Estonia (protocol no. 193/T-16) on 31 May 2010. Participation in the research was voluntary. Written informed consent was obtained from all study participants. The men with Acinetobacter-associated community who had children in the past, had the highest ART success rate (P < 0.05). The women with bacterial vaginosis vaginal microbiome community and with L. iners-predominant and L. gasseri-predominant microbiome had a lower ART success rate than women with the L. crispatus-predominant or the mixed lactic-acid-bacteria-predominant type (P < 0.05). The 15 couples where both partners had beneficial microbiome types had a superior ART success rate of 53%, when compared with the rest of the couples (25%; P = 0.023). Microbiome disturbances in the genital tract of both partners tend to be associated with couple's infertility as well as lower ART success levels and may thus need attention before the ART procedure. The incorporation of genitourinary microbial screening as a part of the diagnostic evaluation process may become routine for ART patients if our results are confirmed by other studies.

Characterization of the equine placental microbial population in healthy pregnancies

In spite of controversy, recent studies present evidence that a microbiome is present in the human placenta. However, there is limited information about a potential equine placental microbiome. In the present study, we characterized the microbial population in the equine placenta (chorioallantois) of healthy prepartum (280 days of gestation, n = 6) and postpartum (immediately after foaling, 351 days of gestation, n = 11) mares, using 16S rDNA sequencing (rDNA-seq). In both groups, the majority of bacteria belonged to the phyla Proteobacteria, Firmicutes, Actinobacteria, and Bacteroidota. The five most abundant genera were Bradyrhizobium, an unclassified Pseudonocardiaceae, Acinetobacter, Pantoea, and an unclassified Microbacteriaceae. Alpha diversity (p < 0.05) and beta diversity (p < 0.01) were significantly different between pre- and postpartum samples. Additionally, the abundance of 7 phyla and 55 genera was significantly different between pre- and postpartum samples. These differences suggest an effect of the caudal reproductive tract microbiome on the postpartum placental microbial DNA composition, since the passage of the placenta through the cervix and vagina during normal parturition had a significant influence on the composition of the bacteria found in the placenta when using 16S rDNA-seq. These data support the hypothesis that bacterial DNA is present in healthy equine placentas and opens the possibility for further exploration of the impact of the placental microbiome on fetal development and pregnancy outcome.

163 Characterisation of reproductive tract microbiome profile of healthy, Bovine Genital Campylobacteriosis infected cattle

163 Characterisation of reproductive tract microbiome profile of healthy, Bovine Genital Campylobacteriosis infected cattle

Similarities in Pathogenetic Mechanisms Underlying the Bidirectional Relationship between Endometriosis and Pelvic Inflammatory Disease

Endometriosis is a common inflammatory disease characterized by the presence of endometrial cells outside of the uterine cavity. Endometriosis affects 10% of women of reproductive age and significantly reduces their quality of life as a result of chronic pelvic pain and infertility. Biologic mechanisms, including persistent inflammation, immune dysfunction, and epigenetic modifications, have been proposed as the pathogenesis of endometriosis. In addition, endometriosis can potentially be associated with an increased risk of pelvic inflammatory disease (PID). Changes in the vaginal microbiota associated with bacterial vaginosis (BV) result in PID or a severe form of abscess formation, tubo-ovarian abscess (TOA). This review aims to summarize the pathophysiology of endometriosis and PID and to discuss whether endometriosis may predispose to PID and vice versa. Papers published between 2000 and 2022 in the PubMed and Google Scholar databases were included. Available evidence supports that women with endometriosis are at increased risk of comorbid PID and vice versa, supporting that endometriosis and PID are likely to coexist. There is a bidirectional relationship between endometriosis and PID that shares a similar pathophysiology, which includes the distorted anatomy favorable to bacteria proliferation, hemorrhage from endometriotic lesions, alterations to the reproductive tract microbiome, and impaired immune response modulated by aberrant epigenetic processes. However, whether endometriosis predisposes to PID or vice versa has not been identified. This review summarizes our current understanding of the pathogenesis of endometriosis and PID and discusses the similarities between them.

The Female Reproductive Tract Microbiome and Cancerogenesis: A Review Story of Bacteria, Hormones, and Disease

The microbiota is the complex community of microorganisms that populate a particular environment in the human body, whereas the microbiome is defined by the entire habitat-microorganisms and their environment. The most abundant and, therefore, the most studied microbiome is that of the gastrointestinal tract. However, the microbiome of the female reproductive tract is an interesting research avenue, and this article explores its role in disease development. The vagina is the reproductive organ that hosts the largest number of bacteria, with a healthy profile represented mainly by Lactobacillus spp. On the other hand, the female upper reproductive tract (uterus, Fallopian tubes, ovaries) contains only a very small number of bacteria. Previously considered sterile, recent studies have shown the presence of a small microbiota here, but there are still debates on whether this is a physiologic or pathologic occurrence. Of particular note is that estrogen levels significantly influence the composition of the microbiota of the female reproductive tract. More and more studies show a link between the microbiome of the female reproductive tract and the development of gynecological cancers. This article reviews some of these findings.

Importance of the female reproductive tract microbiome and its relationship with the uterine environment for health and productivity in cattle: A review

Once thought to be sterile, the reproductive tract microbiome has been characterized due to the transition from culture-dependent identification of bacteria to culture-independent sequencing methods. The urogenital microbiome was first identified in women through the Human Microbiome Project, which led to research in other species such as the bovine. Previous research focused on uterine bacteria associated with postpartum disease, but next generation sequencing methods identified a normal, healthy bacterial community of the reproductive tract of cows and heifers. Bacterial communities are now understood to differ between the uterus and vagina, and throughout the estrous cycle with changes in hormone dominance. In a healthy state, the bacterial communities largely interact with the uterine environment by assisting in maintaining the proper pH, providing and utilizing nutrients and metabolites, and influencing the immunological responses of the reproductive tract. If the bacterial communities become unbalanced due to an increase in potentially pathogenic bacteria, the health and fertility of the host may be affected. Although the presence of a reproductive tract microbiome has become widely accepted, the existence of a placental microbiome and in utero colonization of the fetus is still a popular debate due to conflicting study results. Currently, researchers are evaluating methods to manipulate the reproductive bacterial communities, such as diet changes and utilizing probiotics, to improve reproductive outcomes. The following review discusses the current understanding of the reproductive tract microbiome, how it differs between humans and cattle, and its relationship with the uterine environment.

Female reproductive tract microbiome and early miscarriages.

Miscarriage is one of the main causes of reproductive loss, which can lead to a number of physical and psychological complications and other long-term consequences. However, the role of vaginal and uterine microbiome in such complications is poorly understood. To review the published data on the function of the female reproductive tract microbiome in the pathogenesis of early miscarriages. The articles published over the past 20 years and deposited in PubMed, Google Academy, Scopus, Elibrary, ResearchGate, and EBSCO databases were analyzed. The review presents new data on the impact of the vaginal and uterine microbiome on the local immunity, including defense against sexually transmitted infections, and its association with other factors of miscarriages. The studies on the microbiome of non-pregnant women with recurrent miscarriages in the anamnesis, patients undergoing IVF, and pregnant women with miscarriages, as well as new directions in the microbiome research are discussed. The majority of studies have demonstrated that the dominant species of the vaginal and uterine microbiome in patients with early miscarriages are non-Lactobacillus bacteria. As many of these bacteria have not previously been detected by cultural studies and their role in obstetric complications is not well defined, further research on the female reproductive tract microbiome, including the microbiome of the cervix uteri, is needed to develop new approaches for the prognosis and prevention of miscarriages.

Биомаркеры бактериального вагиноза: аналитический обзор

The microbiome of healthy female reproductive tract is dominated by bacteria producing lactic acid and hydrogen peroxide, which provide infection control by maintaining a low pH level. Qualitative and quantitative changes in the bacterial composition of the vaginal microbiome can lead to the pathology occurrence — bacterial vaginosis (BV). BV increases the risk of contracting sexually transmitted infections, such as HIV, gonococcal, chlamydial, papillomavirus infections, as well as negatively affects a woman's reproductive health. In pregnant women, BV can lead to chorioamnionitis and adverse pregnancy outcomes, including premature rupture of membranes and premature birth. Conventionally, clinical and microscopic methods have been used to diagnose BV. However, these methods require qualified personnel, time expenditure and are characterized by low sensitivity and specificity. Modern diagnostic capabilities, including highly sensitive and specific methods based on the identification of new biomarkers in the vaginal microbiome and vaginal metabolome, can significantly improve the BV diagnosis. The analytical review discusses promising areas of BV laboratory diagnostics. Besides, computer algorithms (AI) can be used to automate the BV diagnosis based on microscopy results. KEYWORDS: bacterial vaginosis, laboratory diagnostics, vaginal microbiome, artificial intelligence. FOR CITATION: Khryanin A.A. Bacterial vaginosis biomarkers: analytical review. Russian Journal of Woman and Child Health. 2023;6(4):374– 379 (in Russ.). DOI: 10.32364/2618-8430-2023-6-4-8.

Periconceptional antibiotic use and spontaneous abortion: A prospective cohort study.

Many reproductive-aged North Americans use antibiotics in the weeks preceding conception or during early pregnancy. Antibiotic use may influence risk of spontaneous abortion (SAB) by disrupting the reproductive tract microbiome or treating harmful infections. However, this association has not been extensively studied. To determine the extent to which periconceptional antibiotic use is associated with the risk of SAB. We analysed data from an internet-based preconception cohort study of pregnancy planners. Eligible participants self-identified as female, were aged 21-45 years, resided in the USA or Canada, and conceived during 12 months of follow-up (n=7890). Participants completed an enrolment questionnaire during June 2013-September 2021 and bimonthly follow-up questionnaires for up to 12 months or until a reported pregnancy, whichever came first. Pregnant participants completed questionnaires in early (~8-9 weeks) and late (~32 weeks) gestation. We assessed antibiotic use, including type (penicillins, nitrofurantoin, cephalosporins and macrolides) and indication for use, during the previous 4 weeks on preconception questionnaires. Participants reported pregnancies and SAB on follow-up and pregnancy questionnaires. We used Cox proportional hazards regression models with gestational weeks as the time scale to estimate hazard ratios (HR) and 95% confidence intervals (CI) for the association between periconceptional antibiotic use and SAB, controlling for potential demographic, medical, and lifestyle confounders. Nineteen percent (n=1537) of pregnancies ended in SAB. Participants reported periconceptional antibiotic use in 8% of pregnancies ending in SAB and 7% not ending in SAB. Periconceptional antibiotic use was not appreciably associated with SAB (adjusted HR 1.06, 95% CI 0.88, 1.28). We observed no strong associations between antibiotic type, indication for use, or recency of exposure and SAB risk. Periconceptional antibiotic use was not appreciably associated with SAB in this study. This association is likely complicated by antibiotic type and dosage, timing of conception, and the individual's overall health.

Adaptive sampling during sequencing reveals the origins of the bovine reproductive tract microbiome across reproductive stages and sexes

Cattle enterprises are one of the major livestock production systems globally and are forecasted to have stable growth in the next decade. To facilitate sustainable live weight production, optimal reproductive performance is essential. Microbial colonisation in the reproductive tract has been demonstrated as one of the factors contributing to bovine reproductive performance. Studies also implied that reproductive metagenomes are different at each stage of the estrous cycle. This study applied Oxford Nanopore Technologies’ adaptive long-read sequencing to profile the bovine reproductive microbiome collected from tropical cattle in northern Queensland, Australia. The microbiome samples were collected from cattle of different sexes, reproductive status and locations to provide a comprehensive view of the bovine reproductive microbiome in northern Australian cattle. Ascomycota, Firmicutes and Proteobacteria were abundant phyla identified in the bovine reproductive metagenomes of Australian cattle regardless of sexes, reproductive status and location. The species level taxonomical investigation suggested that gastrointestinal metagenome and the surrounding environment were potentially the origins of the bovine reproductive metagenome. Functional profiles further affirmed this implication, revealing that the reproductive metagenomes of the prepubertal and postpartum animals were dominated by microorganisms that catabolise dietary polysaccharides as an energy substrate while that of the pregnant animals had the function of harvesting energy from aromatic compounds. Bovine reproductive metagenome investigations can be employed to trace the origins of abnormal metagenomes, which is beneficial for disease prevention and control. Additionally, our results demonstrated different reproductive metagenome diversities between cattle from two different locations. The variation in diversity within one location can serve as the indicator of abnormal reproductive metagenome, but between locations inferences cannot be made. We suggest establishing localised metagenomic indices that can be used to infer abnormal reproductive metagenomes which contribute to abortion or sub-fertility.

The sow microbiome: Current and future perspectives to maximize the productivity in swine herds

The development of new generation sequencing methods and the reduction in the cost per base sequenced over the past few years is drawing the attention of the pig industry to microbiome understanding and modulation. In recent years, there has been an increase in the number of articles published related to microbiome studies in swine. With respect to sows, microbiome studies mainly focused on the gut, with some studies evaluating the reproductive tract and mammary microbiome. However, studies about urinary microbiome are still lacking. The present literature indicates that the microbiome in the sow’s gut can affect the microbiome in other body parts. Moreover, the understanding of the dynamics and interactions among microbial populations within the sow or the herd has led to improvements in animal health and reproductive performance. This review provides new insights related to sow intestinal, urinary, mammary, and reproductive microbiomes and their relationships with reproductive outcomes, diseases, and early colonization in offspring by gathering the most recent work in this field as well as pinpoints information gaps that require further investigation. This literature review also sheds light on the knowledge regarding the role of microbiomes in the reduction of antimicrobial use.

Transkingdom Analysis of the Female Reproductive Tract Reveals Bacteriophages form Communities.

The female reproductive tract (FRT) microbiome plays a vital role in maintaining vaginal health. Viruses are key regulators of other microbial ecosystems, but little is known about how the FRT viruses (virome), particularly bacteriophages that comprise the phageome, impact FRT health and dysbiosis. We hypothesize that bacterial vaginosis (BV) is associated with altered FRT phageome diversity, transkingdom interplay, and bacteriophage discriminate taxa. Here, we conducted a retrospective, longitudinal analysis of vaginal swabs collected from 54 BV-positive and 46 BV-negative South African women. Bacteriome analysis revealed samples clustered into five distinct bacterial community groups (CGs), and further, bacterial alpha diversity was significantly associated with BV. Virome analysis on a subset of baseline samples showed FRT bacteriophages clustering into novel viral state types (VSTs), a viral community clustering system based on virome composition and abundance. Distinct BV bacteriophage signatures included increased alpha diversity along with discriminant Bacillus, Burkholderia, and Escherichia bacteriophages. Bacteriophage-bacteria transkingdom associations were also identified between Bacillus and Burkholderia viruses and BV-associated bacteria, providing key insights for future studies elucidating the transkingdom interactions driving BV-associated microbiome perturbations. In this cohort, bacteriophage-bacterial associations suggest complex interactions, which may play a role in the establishment and maintenance of BV.

Endometrial microbiota composition is associated with reproductive outcome in infertile patients

BackgroundPrevious evidence indicates associations between the female reproductive tract microbiome composition and reproductive outcome in infertile patients undergoing assisted reproduction. We aimed to determine whether the endometrial microbiota composition is associated with reproductive outcomes of live birth, biochemical pregnancy, clinical miscarriage or no pregnancy.MethodsHere, we present a multicentre prospective observational study using 16S rRNA gene sequencing to analyse endometrial fluid and biopsy samples before embryo transfer in a cohort of 342 infertile patients asymptomatic for infection undergoing assisted reproductive treatments.ResultsA dysbiotic endometrial microbiota profile composed of Atopobium, Bifidobacterium, Chryseobacterium, Gardnerella, Haemophilus, Klebsiella, Neisseria, Staphylococcus and Streptococcus was associated with unsuccessful outcomes. In contrast, Lactobacillus was consistently enriched in patients with live birth outcomes.ConclusionsOur findings indicate that endometrial microbiota composition before embryo transfer is a useful biomarker to predict reproductive outcome, offering an opportunity to further improve diagnosis and treatment strategies.4s24pSLHML6tsFwrrAE7giVideo .