Sex, Microbes, and Polycystic Ovary Syndrome

Intestinal Dysbacteriosis Contributes to Persistent Cognitive Impairment after Resolution of Acute Liver Failure

Regulating the gut microbiota alleviates hepatic encephalopathy (HE). Whether it is imperative to withhold treatment for microbial imbalance after liver functional recovery remains unclear. The aim of this work was to elucidate the alterations in cognitive behavior, liver function, synaptic transmission, and brain metabolites in acute liver failure (ALF) mice before and after hepatic function recovery. Towards this end, thioacetamide was injected intraperitoneally to establish an ALF mouse model, which induced HE. Hierarchical clustering analysis indicated that while the liver functions normalized, cognitive dysfunction and intestinal dysbacteriosis occurred in the ALF mice 14 days after thioacetamide injection. In addition, fecal microbiota transplantation from the ALF mice with liver function recovery induced liver injury and cognitive impairment. Alterations in synaptic transmission were found in the ALF mice with liver function improvement, and the correlations between the gut bacteria and synaptic transmission in the cortex were significant. Finally, apparent alterations in the brain metabolic profiles of the ALF mice were detected after liver function improvement by performing 1H nuclear magnetic resonance spectroscopy, suggesting a risk of HE. These results showed that intestinal dysbacteriosis in ALF mice with liver function recovery is sufficient to induce liver injury and cognitive impairment. This indicates that continuous care may be necessary for monitoring microbial imbalance even in patients with ALF-induced HE whose liver function has recovered significantly.

Exploring the causal pathway from gut microbiota to polycystic ovary syndrome: A network Mendelian randomization study

Polycystic ovary syndrome (PCOS) is a complicated endocrine and metabolic syndrome with unclear pathogenesis. The gut microbiota sheds light on the etiology and pathophysiology of PCOS. We used Mendelian randomization (MR) studies to systematically evaluate the pathological mechanism gut microbiota causally associated with PCOS risk. A network MR analysis was performed to estimate the causal effects of gut microbiota and risk factors on PCOS, as well as the mediation effect of risk factors linking gut microbiota to PCOS. The investigation of side effects for the important gut microbiota was subsequently broadened to include phenotypes by performing Phenowide-MR analysis for a range of diseases. Genus Sellimonas id.14369 were causally associated with reduced PCOS risk (odds ratio [OR] = 0.69, 95% confidence interval [CI]: 0.58-0.84, P = 1.22 × 10-4) after multiple testing correction. And Sellimonas retained consistent causal effect estimates after a series of sensitivity analyses. In addition, we observed an indirect effect of Sellimonas on PCOS through body mass index (BMI) using network MR (b = -0.05, 95% CI: -0.09 to -0.01), with a mediated proportion of 12.82% of the total effect. Further, Phenowide-MR analyses showed that the protective effects of Sellimonas on type 2 diabetes and depression (for type 2 diabetes: OR = 0.95, 95% CI: 0.90-0.99, P = .0366; for depression: OR = 0.99, 95% CI: 0.98-1.00, P = .0210). We summarized that the causal path between gut microbiota and type 2 diabetes are also jointly mediated by BMI. Sellimonas may be a protective factor of PCOS, which can affect the occurrence of PCOS through BMI, supporting future studies on the importance of addressing obesity and metabolic issues in preventing and managing PCOS.

Gut Microbiota and Oral Contraceptive Use in Women with Polycystic Ovary Syndrome: A Systematic Review

Background: Polycystic ovary syndrome (PCOS) is one of the most prevalent endocrine syndromes affecting women at reproductive age. With increasing knowledge of the role of the microbiota in the pathogenesis of PCOS, new management strategies began to emerge. However, data on the impact of established treatment regimens, such as metformin and oral contraceptive agents, on the gut microbiota composition are scarce. This study aimed to evaluate the specificity of the gut microbiota in women with PCOS before and after treatment with oral contraceptives. Methods: We have systematically searched the following databases: PubMed/MEDLINE, Scopus, Web of Science and Google Scholar. The last search was performed on 13 May 2024. We included only full-text original research articles written in English. The risk of bias was assessed using a modified version of the Newcastle-Ottawa Scale. Results: The above described search strategy retrieved 46 articles. Additionally, 136 articles were identified and screened through Google Scholar. After removing duplicates, we screened the titles and abstracts, resulting in three eligible articles constituting the final pool. They were published between 2020 and 2022 and are based on three ethnically distinct study populations: Turkish, Spanish and American. The studies included a total of 37 women diagnosed with PCOS and using OCs. Conclusions: OC treatment does not seem to affect the gut microbiota in a significant way in patients with PCOS in short observation. Well-designed randomized controlled studies with adequate, unified sample size are lacking.

Disclosing α-lactalbumin impact on the intestinal and vaginal microbiota of women suffering from polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is one of the most widespread endocrinopathy affecting women of reproductive age with detrimental effects on life quality and health. Among several mechanisms involved in its aetiopathogenesis, recent studies have also postulated the involvement of the vaginal and intestinal microbiota in the development of this disorder. In this study, an accurate insight into the microbial changes associated with PCOS was performed through a pooled-analysis highlighting that this syndrome is characterized by intestinal and vaginal dysbiosis with a reduction of beneficial microorganisms and a higher proportion of potential pathogens. Based on this observation, we evaluated the ability of a milk-derived protein exerting positive outcomes in the management of PCOS, that is, α-lactalbumin (α-LA), to recover PCOS-related dysbiosis. In vitro experiments revealed that this protein improved the growth performances of members of two health-promoting bacterial genera, that is, Bifidobacterium and Lactobacillus, depleted in both intestinal and vaginal microbiota of PCOS-affected women. In addition, α-LA modulated the taxonomic composition and growth performances of the microbial players of the complex intestinal and vaginal microbiota. Finally, an in vivo pilot study further corroborated these observations. The oral administration of α-LA for 30 days to women with PCOS revealed that this protein may have a role in favouring the growth of health-promoting bacteria yet limiting the proliferation of potential pathogens. Overall, our results could pave the way to the use of α-LA as a valid compound with 'prebiotic effects' to limit/restore the PCOS-related intestinal and vaginal dysbiosis.

Gut Microbes in Polycystic Ovary Syndrome and Associated Comorbidities; Type 2 Diabetes, Non-Alcoholic Fatty Liver Disease (NAFLD), Cardiovascular Disease (CVD), and the Potential of Microbial Therapeutics

Polycystic ovary syndrome (PCOS) is one of the most common endocrine anomalies among females of reproductive age, highlighted by hyperandrogenism. PCOS is multifactorial as it can be associated with obesity, insulin resistance, low-grade chronic inflammation, and dyslipidemia. PCOS also leads to dysbiosis by lowering microbial diversity and beneficial microbes, such as Faecalibacterium, Roseburia, Akkermenisa, and Bifidobacterium, and by causing a higher load of opportunistic pathogens, such as Escherichia/Shigella, Fusobacterium, Bilophila, and Sutterella. Wherein, butyrate producers and Akkermansia participate in the glucose uptake by inducing glucagon-like peptide-1 (GLP-1) and glucose metabolism, respectively. The abovementioned gut microbes also maintain the gut barrier function and glucose homeostasis by releasing metabolites such as short-chain fatty acids (SCFAs) and Amuc_1100 protein. In addition, PCOS-associated gut is found to be higher in gut-microbial enzyme β-glucuronidase, causing the de-glucuronidation of conjugated androgen, making it susceptible to reabsorption by entero-hepatic circulation, leading to a higher level of androgen in the circulatory system. Overall, in PCOS, such dysbiosis increases the gut permeability and LPS in the systemic circulation, trimethylamine N-oxide (TMAO) in the circulatory system, chronic inflammation in the adipose tissue and liver, and oxidative stress and lipid accumulation in the liver. Thus, in women with PCOS, dysbiosis can promote the progression and severity of type 2 diabetes, non-alcoholic fatty liver disease (NAFLD), and cardiovascular diseases (CVD). To alleviate such PCOS-associated complications, microbial therapeutics (probiotics and fecal microbiome transplantation) can be used without any side effects, unlike in the case of hormonal therapy. Therefore, this study sought to understand the mechanistic significance of gut microbes in PCOS and associated comorbidities, along with the role of microbial therapeutics that can ease the life of PCOS-affected women.

Fecal microbiota transplantation from patients with polycystic ovary syndrome induces metabolic disorders and ovarian dysfunction in germ-free mice

BACKGROUND

Dysbiosis of the microbiome is a key hallmark of polycystic ovary syndrome (PCOS). However, the interaction between the host and microbiome and its relevance to the pathogenesis of PCOS remain unclear.

METHODS

To evaluate the role of the commensal gut microbiome in PCOS, we gavaged germ-free mice with the fecal microbiota from patients with PCOS or healthy individuals and evaluated the reproductive endocrine features of the recipient mice.

RESULTS

Mice transplanted with fecal microbiota from PCOS patients and those transplanted from healthy controls presented different bacterial profiles and reproductive endocrine features. The fecal microbiota of the mice in the PCOS group was enriched in Phocaeicola, Mediterraneibacter, Oscillospiraceae, Lawsonibacter and Rikenellaceae. Fecal microbiota transplantation (FMT) from PCOS patients induced increased disruption of ovarian functions, lipo-metabolic disturbance, insulin resistance and an obese-like phenotype in recipient mice.

CONCLUSION

Our findings suggest that the microbiome may govern the set point of PCOS-bearing individuals and that gut ecosystem manipulation may be a useful marker and target for the management of PCOS.

A review of metabolic and microbial influences on women with polycystic ovarian syndrome

INTRODUCTION

Polycystic Ovary Syndrome (PCOS) is a prevalent endocrine and metabolic disorder affecting reproductive-aged women worldwide. Characterized by irregular menstruation, signs of hyperandrogenism, polycystic ovaries via ultrasound ovarian dysfunction.

AREA COVERED

The review delves into the intricate pathophysiological mechanisms underlying the syndrome. Dysregulation of the hypothalamic-pituitary-ovarian axis, IR, obesity, and hyperandrogenism contribute to anovulation and follicular dysfunction which is associated with gut dysbiosis, bile metabolites, and an unhealthy diet. Metabolomics and genomics analyses offer insights into the metabolism of bile acids (BAs) and gut microbiota dysbiosis in PCOS. BAs, crucial for metabolic regulation, are influenced by microbes, impacting hormonal balance. Disruptions in gut microbiota contribute to hormonal dysregulation. Interconnected pathways involving BAs and gut microbiota are pivotal in PCOS. Therapeutic implications include a healthy diet, exercise, and interventions targeting gut microbiota modulation and BAs metabolite to alleviate PCOS symptoms and improve metabolic health.

CONCLUSION

PCOS requires a multifaceted, multidisciplinary approach for effective management, including lifestyle changes, medications, and emerging therapies. Tailored strategies considering individual needs and personalized treatment plans are crucial for successful PCOS management. Despite existing knowledge, comprehensive investigations are needed to bridge research gaps and discern the interconnected pathways linking the development of PCOS and the gut-bile axis which are interconnected with metabolic disorders and the development of PCOS. Gut microbiota and hormonal regulation offer promising avenues for innovative therapeutic strategies aimed at addressing the root causes of PCOS and improving patient outcomes.

Electroacupuncture remodels gut microbiota and metabolites in mice with perioperative neurocognitive impairment

Gut microbiota and metabolites are considered key factors in the pathogenesis of perioperative neurocognitive disorders (PND), and the brain-gut axis may be a promising target for PND treatment. Electroacupuncture has been shown to improve a wide range of neurological disorders and to restore function to the gastrointestinal tract. Thus, we hypothesized whether electroacupuncture could remodel gut microbiota and neuroinflammation induced by anesthesia/surgery. First, we observed electroacupuncture at acupoints GV20, LI4 and PC6 significantly improved memory in behavioral tests. Next, we found electroacupuncture decreased the levels of inflammatory factors (NSE, S-100β, IL-6, etc.) in the hippocampus, indicating that nerve inflammation was blocked by electroacupuncture. Furthermore, via 16S rRNA sequence analysis and LC-MS analysis, the gut microbiota and its metabolites were appropriately restored after electroacupuncture treatment. Additionally, we further confirmed the restorative effect of electroacupuncture on PND by fecal transplantation. In conclusion, the role of electroacupuncture in improving cognitive function and protecting neurons may be related to the modulation of gut microbiota and their metabolite dysregulation, thereby inhibiting neuroinflammation in PND mice.

Effects of inulin on intestinal flora and metabolism-related indicators in obese polycystic ovary syndrome patients

CONTEXT

Polycystic ovary syndrome (PCOS), a common endocrine disorder in women of reproductive age, is closely associated with chronic low-grade inflammation and metabolic disturbances. In PCOS mice, dietary inulin has been demonstrated to regulate intestinal flora and inflammation. However, the efficacy of dietary inulin in clinical PCOS remains unclear.

OBJECTIVE

The intestinal flora and related metabolic indexes of obese patients with polycystic ovary syndrome (PCOS) after 3 months of inulin treatment were analyzed.

SETTING AND DESIGN

To analyze the intestinal flora and related metabolic indexes in healthy controls and obese patients with polycystic ovary syndrome after 3 months of inulin treatment.

RESULTS

The results showed that dietary inulin improved sex hormone disorders, reduced BMI and WHR levels in obese women with PCOS. In addition, the inulin intervention reduced plasma TNF-α, IL-1β, IL-6, and MCP-1levels. Inulin intervention increased the abundance of Actinobacteria, Fusobacteria, Lachnospira, and Bifidobacterium, as well as decreased the ratio of F/B and the abundance of proteobacteria, Sutterella, and Enterobacter. Correlation analyses showed a strong relationship among plasma inflammatory factors, sex steroid hormones, and the intestinal flora of patients.

CONCLUSIONS

Dietary inulin may improve obese PCOS women disease through the gut flora-inflammation-steroid hormone pathway.

THE CLINICAL TRIAL REGISTRATION NUMBER

ChiCTR-IOR-17012281.

Polycystic ovary syndrome: Insights into its prevalence, diagnosis, and management with special reference to gut microbial dysbiosis

Polycystic ovary syndrome (PCOS) represents major endocrine and metabolic disorder among women largely characterized by hyperandrogenism and oligomenorrhea precipitates serious complications such as type 2 diabetes, early atherosclerosis, infertility, and endometrial cancer. Several etiological theories were proposed to define the exact cause of the PCOS, which is characterized, by the hypothalamic-pituitary axis, ovarian morphology, and release of adrenal steroid hormones, metabolic syndrome, and hereditary factors. The review explored the role of dysbiosis and the mechanisms through which microbial dysbiosis can affect PCOS development. In recent time, various research groups highlighted the role of microbial gut dysbiosis associated with obesity as potential etiological factor for the PCOS. In the present review, we reviewed the mechanisms attributed to the microbial dysbiosis and treatment approaches to deal with the situation.

Effects of kefir consumption on gut microbiota and health outcomes in women with polycystic ovary syndrome

Polycystic Ovary Syndrome (PCOS), which is common among women of reproductive age, is characterized by low-grade chronic inflammation and is associated with several health problems and dysbiosis. Kefir has been shown to have many beneficial health effects; however, its effect on PCOS is unknown. This study aimed to examine the effect of kefir on the intestinal microbiota and health outcomes in PCOS. In this intervention study, 17 women with PCOS consumed 250 mL/day of kefir (containing Lactobacillus kefiranofaciens subsp. kefiranofaciens, Lactobacillus kefiranofaciens subsp. kefirgranum, Lactobacillus kefiri, Lactobacillus acidophilus, Lactobacillus parakefiri, Lactobacillus bulgaricus, Lactobacillus reuteri, Lactobacillus casei, Lactobacillus fermentum, Lactobacillus helveticus, Lactococcus lactis, Leuconostoc mesentereoides, Bifidobacterium bifidum, Streptococcus thermophilus, Kluyveromyces marxianus, Kluyveromyces lactis, Acetobacter pasteurianus, and Saccharomyces cerevisiae) for 8 weeks. Food consumption and physical activity records, anthropometrical measurements, quality of life, and fecal and blood samples were taken at the study's beginning and end. Quality of life in mental health (58.8 ± 15.08; 64.0 ± 15.23, respectively) and physical function (95.00 and 100.00, respectively) categories showed a significant increase after kefir intervention (p < .05). Additionally, Interleukin-6 (IL-6), one of the inflammatory cytokines, significantly decreased (174.00 and 109.10 ng/L, respectively) (p < .05). The intestinal barrier permeability was evaluated with zonulin, and no significant change was observed. Gut microbiota analysis showed that while the relative abundance of the class Bacilli and genus Lactococcus significantly increased, the genus Holdemania decreased with kefir consumption (p < .05). In conclusion, kefir appears to be beneficial for improving the microbiota and some health outcomes, like reducing inflammation and improving quality of life in PCOS. Therefore, kefir may be useful in the treatment of PCOS.

Metformin modifies plasma microbial-derived extracellular vesicles in polycystic ovary syndrome with insulin resistance

INTRODUCTION

This study investigated changes in plasma microbial-derived extracellular vesicles (EVs) in patients with polycystic ovary syndrome and insulin resistance (PCOS-IR) before and after metformin treatment, and aimed to identify bacterial taxa within EVs that were biologically and statistically significant for diagnosis and treatment.

METHODS

The case-control study was conducted at Xiamen Chang Gung Hospital, Hua Qiao University. Plasma samples were collected from five PCOS-IR patients of childbearing age before and after 3 months of metformin treatment, and the samples were sequenced. The diversity and taxonomic composition of different microbial communities were analyzed through full-length 16 S glycosomal RNA gene sequencing.

RESULTS

After metformin treatment, fasting plasma glucose levels and IR degree of PCOS-IR patients were significantly improved. The 16 S analysis of plasma EVs from metformin-treated patients showed higher microbial diversity. There were significant differences in EVs derived from some environmental bacteria before and after metformin treatment. Notably, Streptococcus salivarius was more abundant in the metformin-treated group, suggesting it may be a potential probiotic.

DISCUSSION

The study demonstrated changes in the microbial composition of plasma EVs before and after metformin treatment. The findings may offer new insights into the pathogenesis of PCOS-IR and provide new avenues for research.

Third-generation PacBio sequencing to explore gut bacteria and gender in colorectal cancer

BACKGROUND

Gut bacteria have an important influence on colorectal cancer (CRC). The differences of gut bacteria between genders have been the hot spots.

OBJECTIVE

To analyze the relationship between gut bacteria and gender differences in patients with CRC.

METHODS

A total of 212 patients with CRC and 212 healthy volunteers were recruited. The subjects' fecal samples were obtained, and the fecal microorganisms were analyzed by the third-generation sequencing PacBio. The composition of gut bacteria was analyzed. Linear discriminant analysis Effect Size (LEfSe) was used to analyze the differences in gut bacteria. Pearson coefficient was used to calculate the correlation between differential bacteria. CRC risk prediction models were used to rank the importance of effective differential bacteria.

RESULTS

Escherichia flexneri and Phocaeicola vulgatus were the most frequent bacteria in both male and female CRC patients. Bacteroides, Verrucomicrobia and Akkermansiaceae were highly enriched in male CRC group, while Bacteroidetes, Phocaeicola and Tissierellales were highly enriched in female CRC group. Peptostreptococcus anaerobius and Phocaeicola vulgatus were important CRC related bacteria in males and females, respectively. Peptostreptococcus anaerobius was the most important characteristic bacterium of males (AUC = 0.951), and the sensitivity and specificity of the discovery set were 78.74 % and 93.98 %, respectively. Blautia stercoris was the most important characteristic bacterium of females (AUC = 0.966), and the sensitivity and specificity of the discovery set were 90.63 % and 90.63 %, respectively.

CONCLUSION

Gut bacteria varied in different genders. Therefore, gender should be considered when gut bacteria are applied in the diagnose and prevention of CRC.

Gut bacteria convert glucocorticoids into progestins in the presence of hydrogen gas

Recent studies suggest that human-associated bacteria interact with host-produced steroids, but the mechanisms and physiological impact of such interactions remain unclear. Here, we show that the human gut bacteria Gordonibacter pamelaeae and Eggerthella lenta convert abundant biliary corticoids into progestins through 21-dehydroxylation, thereby transforming a class of immuno- and metabo-regulatory steroids into a class of sex hormones and neurosteroids. Using comparative genomics, homologous expression, and heterologous expression, we identify a bacterial gene cluster that performs 21-dehydroxylation. We also uncover an unexpected role for hydrogen gas production by gut commensals in promoting 21-dehydroxylation, suggesting that hydrogen modulates secondary metabolism in the gut. Levels of certain bacterial progestins, including allopregnanolone, better known as brexanolone, an FDA-approved drug for postpartum depression, are substantially increased in feces from pregnant humans. Thus, bacterial conversion of corticoids into progestins may affect host physiology, particularly in the context of pregnancy and women's health.

Gut Microbiome and Polycystic Ovary Syndrome: Interplay of Associated Microbial-Metabolite Pathways and Therapeutic Strategies

Polycystic ovary syndrome (PCOS) is a multifaceted disease with an intricate etiology affecting reproductive-aged women. Despite attempts to unravel the pathophysiology, the molecular mechanism of PCOS remains unknown. There are no effective or suitable therapeutic strategies available to ameliorate PCOS; however, the symptoms can be managed. In recent years, a strong association has been found between the gut microbiome and PCOS, leading to the formulation of novel ideas on the genesis and pathological processes of PCOS. Further, gut microbiome dysbiosis involving microbial metabolites may trigger PCOS symptoms via many mechanistic pathways including those associated with carbohydrates, short-chain fatty acids, lipopolysaccharides, bile acids, and gut-brain axis. We present the mechanistic pathways of PCOS-related microbial metabolites and therapeutic opportunities available to treat PCOS, such as prebiotics, probiotics, and fecal microbiota therapy. In addition, the current review highlights the emerging treatment strategies available to alleviate the symptoms of PCOS.

Characterization of the gut microbiota in polycystic ovary syndrome with dyslipidemia

BACKGROUND

Polycystic ovary syndrome (PCOS) is an endocrinopathy in childbearing-age females which can cause many complications, such as diabetes, obesity, and dyslipidemia. The metabolic disorders in patients with PCOS were linked to gut microbial dysbiosis. However, the correlation between the gut microbial community and dyslipidemia in PCOS remains unillustrated. Our study elucidated the different gut microbiota in patients with PCOS and dyslipidemia (PCOS.D) compared to those with only PCOS and healthy women.

RESULTS

In total, 18 patients with PCOS, 16 healthy females, and 18 patients with PCOS.D were enrolled. The 16 S rRNA sequencing in V3-V4 region was utilized for identifying the gut microbiota, which analyzes species annotation, community diversity, and community functions. Our results showed that the β diversity of gut microbiota did not differ significantly among the three groups. Regarding gut microbiota dysbiosis, patients with PCOS showed a decreased abundance of Proteobacteria, and patients with PCOS.D showed an increased abundance of Bacteroidota compared to other groups. With respect to the gut microbial imbalance at genus level, the PCOS.D group showed a higher abundance of Clostridium_sensu_stricto_1 compared to other two groups. Furthermore, the abundances of Faecalibacterium and Holdemanella were lower in the PCOS.D than those in the PCOS group. Several genera, including Faecalibacterium and Holdemanella, were negatively correlated with the lipid profiles. Pseudomonas was negatively correlated with luteinizing hormone levels. Using PICRUSt analysis, the gut microbiota community functions suggested that certain metabolic pathways (e.g., amino acids, glycolysis, and lipid) were altered in PCOS.D patients as compared to those in PCOS patients.

CONCLUSIONS

The gut microbiota characterizations in patients with PCOS.D differ from those in patients with PCOS and controls, and those might also be related to clinical parameters. This may have the potential to become an alternative therapy to regulate the clinical lipid levels of patients with PCOS in the future.

The influence and therapeutic effect of microbiota in systemic lupus erythematosus

Systemic erythematosus lupus (SLE) is an autoimmune disease involving multiple organs that poses a serious risk to the health and life of patients. A growing number of studies have shown that commensals from different parts of the body and exogenous pathogens are involved in SLE progression, causing barrier disruption and immune dysregulation through multiple mechanisms. However, they sometimes alleviate the symptoms of SLE. Many factors, such as genetic susceptibility, metabolism, impaired barriers, food, and sex hormones, are involved in SLE, and the microbiota drives the development of SLE either by depending on or interacting with these factors. Among these, the crosstalk between genetic susceptibility, metabolism, and microbiota is a hot topic of research and is expected to lay the groundwork for the amelioration of the mechanism, diagnosis, and treatment of SLE. Furthermore, the microbiota has great potential for the treatment of SLE. Ideally, personalised therapeutic approaches should be developed in combination with more specific diagnostic methods. Herein, we provide a comprehensive overview of the role and mechanism of microbiota in lupus of the intestine, oral cavity, skin, and kidney, as well as the therapeutic potential of the microbiota.

Unraveling intestinal microbiota's dominance in polycystic ovary syndrome pathogenesis over vaginal microbiota

Background

Polycystic ovary syndrome (PCOS) is a prevalent endocrine disease in women, intricately linked to hormonal imbalances. The microbiota composition plays a pivotal role in influencing hormonal levels within the body. In this study, we utilized a murine model to investigate how intestinal and vaginal microbiota interact with hormones in the development of PCOS.

Methods

Twenty female mice were randomly assigned to the normal group (N) and the model group (P), where the latter received daily subcutaneous injections of 0.1 mL DHEA (6 mg/100 g). Throughout the experiment, we evaluated the PCOS mouse model by estrus cycle, serum total testosterone (T), prolactin (PRL) and luteinizing hormone (LH) levels, and ovarian pathological morphology. The microbial composition in both intestinal content and vaginal microbiota were studied by 16S rRNA gene high-throughput sequencing.

Results

Compared with the N group, the P group showed significant increases in body weight, T, and PRL, with significant decrease in LH. Ovaries exhibited polycystic changes, and the estrous cycle was disrupted. The intestinal microbiota result shows that Chao1, ACE, Shannon and Simpson indexes were decreased, Desulfobacterota and Acidobacteriota were increased, and Muribaculaceae, Limosilactobacillus and Lactobacillus were decreased in the P group. T was significantly positively correlated with Enterorhabdus, and LH was significantly positively correlated with Lactobacillus. The analysis of vaginal microbiota revealed no significant changes in Chao1, ACE, Shannon, and Simpson indices. However, there were increased in Firmicutes, Bacteroidota, Actinobacteriota, Streptococcus, and Muribaculaceae. Particularly, Rodentibacter displayed a robust negative correlation with other components of the vaginal microbiota.

Conclusion

Therefore, the response of the intestinal microbiota to PCOS is more significant than that of the vaginal microbiota. The intestinal microbiota is likely involved in the development of PCOS through its participation in hormonal regulation.

High Fat Diet and Polycystic Ovary Syndrome (PCOS) in Adolescence: An Overview of Nutritional Strategies

Polycystic ovary syndrome (PCOS) is a multifaceted and heterogeneous disorder, linked with notable reproductive, metabolic, and psychological outcomes. During adolescence, key components of PCOS treatment involve weight loss achieved through lifestyle and dietary interventions, subsequently pursued by pharmacological or surgical therapies. Nutritional interventions represent the first-line therapeutic approach in adolescents affected by PCOS, but different kinds of dietary protocols exist, so it is necessary to clarify the effectiveness and benefits of the most well-known nutritional approaches. We provided a comprehensive review of the current literature concerning PCOS definition, pathophysiology, and treatment options, highlighting nutritional strategies, particularly those related to high-fat diets. The high-fat nutritional protocols proposed in the literature, such as the ketogenic diet (KD), appear to provide benefits to patients with PCOS in terms of weight loss and control of metabolic parameters. Among the different types of KD studies, very low-calorie ketogenic diets (VLCKD), can be considered an effective dietary intervention for the short-term treatment of patients with PCOS. It rapidly leads to weight loss alongside improvements in body composition and metabolic profile. Even though extremely advantageous, long-term adherence to the KD is a limiting factor. Indeed, this dietary regimen could become unsustainable due to the important restrictions required for ketosis development. Thus, a combination of high-fat diets with more nutrient-rich nutritional regimens, such as the Mediterranean diet, can amplify positive effects for individuals with PCOS.

Bacterial Vaginosis (BV) and Vaginal Microbiome Disorders in Women Suffering from Polycystic Ovary Syndrome (PCOS)

Introduction: Polycystic ovary syndrome (PCOS) is a multifactorial, heterogeneous endocrine and metabolic disorder in women. Due to its association with the menstrual cycle and fertility disorders, the importance of this problem is emphasized especially in patients of reproductive age. Based on a number of analyses, the effect of PCOS on altering the diversity of the microbiome (e.g., intestinal or vaginal) is suggested. Vaginal dysbiosis can result in BV (bacterial vaginosis). The purpose of this study was to assess the prevalence of BV in patients with PCOS, as well as to determine the most reliable diagnostic factors. Material and Methods: Retrospective analysis of microbiological findings (2018-2022) of PCOS patients (n = 594) of reproductive age. The present analysis focused on the results of patients with PCOS (n = 380) and vaginal discharge with pH ≥ 4.4 and suspected BV. Biological material was a vaginal swab/vaginal secretion. The most commonly used routine methods for assessing BV were the Amsel analysis and the Nugent scoring system. Results: Patients with PCOS and vaginal fluid pH ≥ 4.4 and suspected BV (n = 380) accounted for 64% of all PCOS patients (n = 594). The relationship between pH and detection of "clue cells" showed significant dependency and increased with leukocytes. The pH measurement also showed dependency on high G. vaginalis counts. In addition, the elimination of lactic acid bacteria (LAB) in vaginal secretions was associated with an increase in the number of leukocytes with increasing pH values. A marked increase in G. vaginalis was found in more than half (56.8%) of PCOS women (n = 380) with suspected BV. No dependency was observed between the absence of LAB and the diagnosis of BV on a positive G. vaginalis culture. Of the n = 380 patients with PCOS, 191 (50%) had a Nugent score ≥ 7 positive for BV. No dependency was observed between the number of patients with Candida sp. in vaginal secretions and pH, BV (with clue cells), or elevated leukocyte levels. The LRM was adjusted and the statistical model represented by the following formula was obtained: log(p/(1 - p)) = -1.18 + 1.24 × Group4.6 + 1.08 × Group4.8 + 1.66 × Group5.4. Conclusions: Based on the present analysis, BV appears to be more common in patients with PCOS than in the non-PCOS population. Chronic inflammation in PCOS patients and abnormalities in the vaginal microbiome may predispose to the development of BV. In women with PCOS, BV may be one of the unrecognized causes of infertility or complications of pregnancy. Despite the potential link between PCOS and the development of BV, the extent to which this syndrome contributes to vaginal dysbiosis and reproductive complications requires further study.

The Effect of Sex on the Therapeutic Efficiency of Immune Checkpoint Inhibitors: A Systematic Review and Meta-Analysis Based on Randomized Controlled Trials

BACKGROUND

Sex is an important factor influencing the immune system, and the distribution of tumors, including their types and subtypes, is characterized by sexual dichotomy. The aim of this study was to investigate whether there is an association between sex and the treatment effect of immune checkpoint inhibitors (ICI).

METHODS

Four bibliographic databases were searched. Studies of randomized controlled trials (RCTs) assessing the efficacy of ICI were identified and used, and the primary endpoint was the difference in efficacy of ICI between males and females, presented as overall survival (OS), progression-free survival (PFS) and recurrence-free survival (RFS). The study calculated the pooled HRs and 95% CIs for OS, PFS and RFS for males and females using a random effects model or a fixed effects model, and thereby assessed the effect of sex on the efficacy of ICI treatment. This study is registered with PROSPERO (CRD42022370939).

RESULTS

A total of 103 articles, including a total of 63,755 patients with cancer, were retrieved from the bibliographic database, of which approximately 70% were males. In studies with OS as the outcome, the combined hazard ratio (HR) was 0.77 (95% CI 0.74-0.79) for male patients treated with ICI and 0.81 (95% CI 0.78-0.85) for female patients compared to controls, respectively. The difference in efficacy between males and females was significant.

CONCLUSIONS

ICI therapy, under suitable conditions for its use, has a positive impact on survival in various types of tumors, and male patients benefit more than females. It may be necessary to develop different tumor immunotherapy strategies for patients of different sexes.

Changes in Gut Microbiota Associated with Parity in Large White Sows

As one of the most critical economic traits, the litter performance of sows is influenced by their parity. Some studies have indicated a connection between the gut microbiota and the litter performance of animals. In this study, we examined litter performance in 1363 records of different parities of Large White sows. We observed a marked decline in TNB (Total Number Born) and NBH (Number of Healthy Born) We observed a marked decline in TNB (Total Number Born) and NBH (Number of Healthy Born) among sows with parity 7 or higher. To gain a deeper understanding of the potential role of gut microbiota in this phenomenon, we conducted 16S rRNA amplicon sequencing of fecal DNA from 263 Large White sows at different parities and compared the changes in their gut microbiota with increasing parity. The results revealed that in comparison to sows with a parity from one to six, sows with a parity of seven or higher exhibited decreased alpha diversity in their gut microbiota. There was an increased proportion of pathogenic bacteria (such as Enterobacteriaceae, Streptococcus, and Escherichia-Shigella) and a reduced proportion of SCFA-producing families (such as Ruminococcaceae), indicating signs of inflammatory aging. The decline in sow function may be one of the primary reasons for the reduction in their litter performance.

Exploration of the pathogenesis of polycystic ovary syndrome based on gut microbiota: A review

Polycystic ovary syndrome (PCOS) is a complex disorde7r influenced by genetic, neuroendocrine, metabolic, environmental, and lifestyle factors. This paper delves into the increasingly recognized role of gut microbiota dysbiosis in the onset and progression of PCOS. Utilizing advances in next-generation sequencing and metabolomics, the research examines the intricate interaction between the gut microbiota and the central nervous system via the gut-brain axis. The paper highlights how disruptions in gut microbiota contribute significantly to PCOS by modulating the release of gut-brain peptides and activating inflammatory pathways. Through such mechanisms, gut microbiota dysbiosis is implicated in hyperandrogenism, insulin resistance, chronic inflammation, and metabolic disorders associated with PCOS. While the relationship between gut microbiota and PCOS has begun to be elucidated, this paper underscores the need for further research to identify specific bacterial strains and their metabolic byproducts as potential therapeutic targets. Therefore, comprehensive studies are urgently needed to understand and fundamentally treat the pathophysiological processes of PCOS, offering valuable insights for future treatment and prevention strategies.

Interleukin-22 promotes proliferation and reverses LPS-induced apoptosis and steroidogenesis attenuation in human ovarian granulosa cells: implications for polycystic ovary syndrome pathogenesis

OBJECTIVE

Interleukin 22 (IL-22) plays a role in inflammatory diseases. However, whether IL-22 affects the function of ovarian granulosa cells (GCs) and its relationship with Polycystic Ovary Syndrome (PCOS)remains unclear.

METHODS

We investigated the level of IL-22 in human follicular fluid using ELISA. The expression and localization of the IL-22 receptor 1 (IL-22R1) in GCs were investigated by RT-PCR and immunofluorescence staining, respectively. The proliferation of KGN cells (human GCs line) was assessed by CCK-8 assay and EdU assay after treatment with recombinant human IL-22 (rhIL-22) and lipopolysaccharide (LPS). Apoptosis was assessed using flow cytometry. Apoptotic proteins and steroidogenic genes were detected by western blotting.

RESULTS

ELISA's results showed that compared with the control group, PCOS patients showed lower expression of IL-22 in follicular fluid. Immunofluorescence showed that IL-22R1 is expressed and localized in human granulosa cell membranes. IL-22 promoted cell proliferation and reversed LPS-induced inhibition of cell proliferation. IL-22 alone did not affect apoptotic or steroidogenic protein expression, however, it reversed LPS-induced apoptosis via downregulation of Bcl-2, upregulation of Bax and cleaved caspase-3, and restoration of LPS-downregulated StAR, CYP11A1, and CYP19A1 expression. Western blotting confirmed that IL-22 activated the JAK2/STAT3 signaling.

CONCLUSION

IL-22 promotes cell proliferation, inhibits apoptosis, and regulates KGN cell steroidogenesis confronted with LPS, and decreased IL-22 may be involved in the development of PCOS.

Gut microbiota and risk of polycystic ovary syndrome: Insights from Mendelian randomization

Background

Polycystic ovary syndrome (PCOS) is a multifaceted endocrine and metabolic syndrome with complex origins and pathogenesis that has not yet been fully elucidated. Recently, the interconnection between gut microbiota and metabolic diseases has gained prominence in research, generating new insights into the correlation between PCOS and gut microbiota composition. However, the causal link between PCOS and gut microbiota remains relatively unexplored, indicating a crucial gap in current research.

Methods

We conducted a two-sample Mendelian randomization analysis using summary statistics obtained from the MiBioGen Consortium's extensive genome-wide association studies (GWAS) meta-analysis, focusing on the gut microbiota. Summary statistics for PCOS were acquired from the FinnGen Consortium R7 release data. Various statistical approaches, including inverse variance weighted, MR-Egger, maximum likelihood, weighted model, and weighted median, have been employed to investigate the causal association between the gut microbiota and PCOS. Additionally, we performed a reverse causal analysis. Cochran's Q statistic was used to assess the heterogeneity of the instrumental variables. Regarding the relationships between PCOS and specific genera within the gut microbiota, a significance level of P < 0.05 was observed, but only when q ≥ 0.1.

Results

Our analysis revealed that specific microbial genera, namely Bilophila (P = 4.62 × 10-3), Blautia (P = 0.02), and Holdemania (P = 0.04), displayed a protective effect against PCOS. Conversely, the presence of the Lachnospiraceae family of bacteria was associated with a detrimental effect on PCOS (P = 0.04). Furthermore, reverse Mendelian randomization analysis confirmed the significant influence of Lachnospiraceae on PCOS. No significant variations in instrumental variables or evidence of horizontal pleiotropy were observed.

Conclusions

The results revealed a definitive causal link between PCOS and the presence of Bilophila, Blautia, Holdemania, and Lachnospiraceae in the gut microbiota. This discovery could provide pivotal insights, leading to novel preventive and therapeutic approaches for PCOS.

Alterations of gut microbiota biodiversity and relative abundance in women with PCOS: A systematic review and meta-analysis

BACKGROUND

Numerous studies have implicated that the gut microbiota is associated with polycystic ovary syndrome (PCOS). However, a comprehensive data-based summary shown that the effects of the PCOS on the gut microbiota is minimal. We aim to assess the alterations of gut microbiota in women with PCOS.

METHODS

An electronic search of PubMed, Web of Science, Embase, Cochrane Library and Ovid was conducted for eligible studies published from inception to 28 March 2023, without any language or regional restrictions. We used Newcastle-Ottawa Quality Assessment Scale (NOS) to complete the assessment of the risk of bias and Stata 15.1 software to performed meta-analysis.

RESULTS

There were 19 human observational studies in total with 617 women with PCOS and 439 healthy individuals were identified. Compared to the control group, the Chao index (WMD -28.88, 95% CI -45.78 to -11.98, I2 = 100%), Shannon index (WMD -0.11, 95% CI -0.18 to 0.00, I2 = 92.2%); and observed operational taxonomic units (OTUs) counts (WMD - 23.48, 95% CI -34.44 to -12. 53, I2 = 99.6%) were significantly lower in women with PCOS. The relative abundance of Bacteroidaceae was significantly higher (WMD 0.12, 95% CI 0.02 to 0.22, I2 = 9.2%), however there were no statistical differences in Actinobacteria, Bacteroidetes, Firmicutes, Proteobacteria, Alcaligenaceae, Bifidobacteriaceae, Clostridiaceae, Enterobacteriaceae, Lachnospiraceae, Prevotellaceae, Ruminococcaceae, Veillonellaceae, Bacteroides, Bifidobacterium, Blautia, Dialister, Escherichia-Shigella, Faecalibacterium, Lachnoclostridium, Lachnospira, Megamonas, Phascolarctobacterium, Prevotella, Roseburia, and Subdoligranulum.

CONCLUSION

We demonstrated the alpha diversity of gut microbiota and the relative abundance of Bacteroidaceae in women with PCOS are altered. The results indicates that dysbiosis may be a potential pathogenetic factor in PCOS and provided reliable information to investigate the role of gut microbiota in the development and progression of PCOS.

Effect of the ketogenic diet on gut microbiome composition and metabolomics in polycystic ovarian syndrome rats induced by letrozole and a high-fat diet

OBJECTIVES

The ketogenic diet (KD) is recommended to improve polycystic ovary syndrome (PCOS); however, its mechanisms of action are unclear. We aimed to study the effects and mechanisms of action of the KD on the gut microbiome and metabolites in PCOS rats and determine whether the sex hormone regulatory effects are related to modulations of the gut microbiota and metabolites.

METHODS

PCOS was induced with a high-fat diet and letrozole in the rats. A KD was fed to rats for 8 wk, serum samples were collected for biochemical analysis, and the rats' fecal samples were subjected to 16S ribosomal RNA sequencing and metabolomic analysis.

RESULTS

Feeding with a KD for 8 wk suppressed body weight gain, decreased luteinizing hormone and androgen levels, and improved insulin levels. Furthermore, the KD reversed the dysregulation of the gut microbiota in PCOS rats by adjusting the ratio of firmicutes and bacteroidetes. Also, the KD was involved in hormonal metabolic pathways by reducing the levels of some metabolites (such as testosterone and 7α-hydroxytestosterone) that are closely related to gut microbes.

CONCLUSIONS

The KD improved the clinical phenotype and insulin resistance in PCOS rats and altered the composition of the gut microbiome and metabolites, which were associated with androgen metabolism, representing a potential mechanism for mediating the effects of the KD on sex hormone metabolism in PCOS. However, our study found contradictory effects of KD on the gut microbiome in PCOS, which need further research.

Microbiota Transplant and Gynecological Disorders: The Bridge between Present and Future Treatments

Fecal microbiota transplantation (FMT) is a procedure that involves transferring fecal bacteria from a healthy donor to a patients' intestines to restore gut-immunity homeostasis. While FMT was primarily supposed to treat gastrointestinal disorders such as inflammatory bowel disease and irritable bowel syndrome-and especially Clostridium difficile infection (currently the only used as clinical treatment)-recent research has suggested that it may also become a potential treatment for gynecological disorders, including endometriosis and polycystic ovary syndrome (PCOS). On the contrary, vaginal microbiota transplantation (VMT) is a newer and less commonly used procedure than the FMT approach, and its potential applications are still being explored. It involves direct grafting of the entire vaginal microbiota of healthy women into the vaginal tract of patients to easily rebuild the local microbiota environment, restoring vaginal eubiosis and relieving symptoms. Like FMT, VMT is thought to have potential in treating different microbiota-related conditions. In fact, many gynecological disorders, such as bacterial vaginosis and vulvovaginal candidiasis, are thought to be caused by an imbalance in the vaginal microbiota. In this review, we will summarize the development, current challenges, and future perspectives of microbiota transplant, with the aim of exploring new strategies for its employment as a promising avenue for treating a broad range of gynecological diseases.

Alteration in gut mycobiota of patients with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a serious disease characterized by high androgen, insulin resistance (IR), hyperglycemia, and obesity, leading to infertility. The gut mycobiota has been reported to evolve in metabolic diseases including obesity, hyperglycemia, and fatty liver. However, little is known about the gut mycobiota and PCOS. In the current study, we recruited 17 PCOS patients and 17 age-matched healthy controls for community structure and functional analysis of the gut mycobiota. The results showed that PCOS patients have reduced diversity and richness of the gut microbiota compared with healthy controls. β-Diversity analysis showed that the community structure of the gut microbiota of patients with PCOS was significantly different from healthy controls. At the phylum level, PCOS patients have reduced Basidiomycota and increased Ascomycota compared with healthy controls. At the family level, the higher relative abundance of Saccharomycetaceae and lower Trichosporonaceae and Ascomycota_unclassified were detected in PCOS patients than in healthy controls. At the genus level, different microbial compositions were also observed between PCOS patients and healthy controls. In addition, PICRUSt2 showed that patients with PCOS have different microbial functions in the gut compared with healthy controls. LEfSe indicated that Saccharomyces and Lentinula were enriched in the fecal samples of PCOS patients, while Aspergillus was depleted compared with healthy controls. Our finding indicates that PCOS patients have different community structures and functions of the gut mycobiota, which provides new insight into PCOS pathogenesis and intervention. IMPORTANCE It was found that intestinal fungi as well as serum metabolites in PCOS patients were significantly different from those in healthy subjects. However, no studies have been done to show exactly which fungus interacts with which bacteria in humans or which fungus acts alone. As fungal research progresses, it will be possible to fill this gap.

The Upper Reproductive System Microbiome: Evidence beyond the Uterus

The microbiome of the female upper reproductive system has garnered increasing recognition and has become an area of interest in the study of women's health. This intricate ecosystem encompasses a diverse consortium of microorganisms (i.e., microbiota) and their genomes (i.e., microbiome) residing in the female upper reproductive system, including the uterus, the fallopian tubes, and ovaries. In recent years, remarkable advancements have been witnessed in sequencing technologies and microbiome research, indicating the potential importance of the microbial composition within these anatomical sites and its impact in women's reproductive health and overall well-being. Understanding the composition, dynamics, and functions of the microbiome of the female upper reproductive system opens up exciting avenues for improving fertility, treating gynecological conditions, and advancing our comprehension of the intricate interplay between the microbiome and the female reproductive system. The aim of this study is to compile currently available information on the microbial composition of the female upper reproductive system in humans, with a focus beyond the uterus, which has received more attention in recent microbiome studies compared with the fallopian tubes and ovaries. In conclusion, this review underscores the potential role of this microbiome in women's physiology, both in health and disease.

Perturbations in gut microbiota composition in patients with polycystic ovary syndrome: a systematic review and meta-analysis

BACKGROUND

The results of human observational studies on the correlation between gut microbiota perturbations and polycystic ovary syndrome (PCOS) have been contradictory. This study aimed to perform the first systematic review and meta-analysis to evaluate the specificity of the gut microbiota in PCOS patients compared to healthy women.

METHODS

Literature through May 22, 2023, was searched on PubMed, Web of Science, Medline, Embase, Cochrane Library, and Wiley Online Library databases. Unreported data in diversity indices were filled by downloading and processing raw sequencing data. Systematic review inclusion: original studies were eligible if they applied an observational case-control design, performed gut microbiota analysis and reported diversity or abundance measures, sampled general pre-menopausal women with PCOS, and are longitudinal studies with baseline comparison between PCOS patients and healthy females. Systematic review exclusion: studies that conducted interventional or longitudinal comparisons in the absence of a control group. Two researchers made abstract, full-text, and data extraction decisions, independently. The Joanna Briggs Institute Critical Appraisal Checklist was used to assess the methodologic quality. Hedge's g standardized mean difference (SMD), confidence intervals (CIs), and heterogeneity (I2) for alpha diversity were calculated. Qualitative syntheses of beta-diversity and microbe alterations were performed.

RESULTS

Twenty-eight studies (n = 1022 patients, n = 928 control) that investigated gut microbiota by collecting stool samples were included, with 26 and 27 studies having provided alpha-diversity and beta-diversity results respectively. A significant decrease in microbial evenness and phylogenetic diversity was observed in PCOS patients when compared with control participants (Shannon index: SMD = - 0.27; 95% CI, - 0.37 to - 0.16; phylogenetic diversity: SMD = - 0.39; 95% CI, -- 0.74 to - 0.03). We also found that reported beta-diversity was inconsistent between studies. Despite heterogeneity in bacterial relative abundance, we observed depletion of Lachnospira and Prevotella and enrichment of Bacteroides, Parabacteroides, Lactobacillus, Fusobacterium, and Escherichia/Shigella in PCOS. Gut dysbiosis in PCOS, which might be characterized by the reduction of short-chain fatty acid (SCFA)-producing and bile-acid-metabolizing bacteria, suggests a shift in balance to favor pro-inflammatory rather than anti-inflammatory bacteria.

CONCLUSIONS

Gut dysbiosis in PCOS is associated with decreased diversity and alterations in bacteria involved in microbiota-host crosstalk.

TRIAL REGISTRATION

PROSPERO registration: CRD42021285206, May 22, 2023.

The association between gut microbiome and PCOS: evidence from meta-analysis and two-sample mendelian randomization

BACKGROUND

Increasing evidence from observational studies and clinical experimentation has indicated a link between the gut microbiotas (GMs) and polycystic ovary syndrome (PCOS), however, the causality and direction of causality between gut microbiome and PCOS remains to be established.

METHODS

We conducted a comprehensive search of four databases-PubMed, Cochrane Library, Web of Science, and Embase up until June 1, 2023, and subjected the results to a meta-analysis. In this study, a bidirectional two-sample Mendelian randomization (MR) analysis was employed to investigate the impact of gut microbiota on polycystic ovary syndrome (PCOS). The genome-wide association study (GWAS) data for PCOS comprised 113,238 samples, while the GWAS data for gut microbiota were derived from the MiBioGen consortium, encompassing a total sample size of 18,340 individuals. As the largest dataset of its kind, this study represents the most comprehensive genome-wide meta-analysis concerning gut microbiota composition to date. Single nucleotide polymorphisms (SNPs) were selected as instrumental variables at various taxonomic levels, including Phylum, Class, Order, Family, and Genus. The causal associations between exposures and outcomes were assessed using four established MR methods. To correct for multiple testing, the false discovery rate (FDR) method was applied. The reliability and potential biases of the results were evaluated through sensitivity analysis and F-statistics.

RESULTS

The meta-analysis incorporated a total of 20 studies that met the criteria, revealing a close association between PCOS and specific gut microbiota species. As per the results from our MR analysis, we identified six causal associations between the gut microbiome and polycystic ovary syndrome (PCOS). At the genus level, Actinomyces (ORIVW = 1.369, FDR = 0.040), Streptococcus (ORIVW = 1.548, FDR = 0.027), and Ruminococcaceae UCG-005 (ORIVW = 1.488, FDR = 0.028) were identified as risk factors for PCOS. Conversely, Candidatus Soleaferrea (ORIVW = 0.723, FDR = 0.040), Dorea (ORIVW = 0.580, FDR = 0.032), and Ruminococcaceae UCG-011 (ORIVW = 0.732, FDR = 0.030) were found to be protective factors against PCOS. Furthermore, the MR-PRESSO global test and MR-Egger regression indicated that our study results were not affected by horizontal pleiotropy (p > 0.05). Finally, the leave-one-out analysis corroborated the robustness of the MR findings.

CONCLUSION

Both our meta-analysis and MR study indicates that there is a causal relationship between the gut microbiome and PCOS, which may contribute to providing novel insights for the development of new preventive and therapeutic strategies for PCOS.

Probiotics and Polycystic Ovary Syndrome: A Perspective for Management in Adolescents with Obesity

Polycystic ovary syndrome (PCOS) affects a considerable percentage of females of reproductive age. PCOS is an obesity-related condition and its effects are greatly amplified by obesity. Even though the pathogenesis of PCOS remains complex and has not been fully elucidated, a link between obesity, PCOS, and dysbiosis has been described. The potential role of the gut microbiota in the development and progression of PCOS and its associated symptoms has also been reported. The aim of this narrative review is to present a non-systematic analysis of the available literature on the topic of probiotics and PCOS in adolescents with obesity in order to revise the beneficial effects of probiotics/symbiotic supplementation on hormonal and metabolic profiles and inflammatory conditions. The effectiveness of probiotics/synbiotics in PCOS has been supported. The literature suggests that probiotic/symbiotic supplementation may ameliorate hormonal profiles, inflammatory indicators, and lipid metabolism disturbances caused by PCOS. Studies also show improvements in weight, BMI, insulin, and HOMA-IR, including a potential role it plays in protecting fertility. Even though further studies are needed to confirm these findings, particularly in adolescent patients, probiotic supplementation may be considered a solution for managing PCOS in adolescents with obesity.

Effects of gut microbiota on omega-3-mediated ovary and metabolic benefits in polycystic ovary syndrome mice

BACKGROUND

Polycystic ovary syndrome (PCOS) is a common reproductive endocrine disorder that frequently exhibits low-grade inflammation, pro-oxidant activity, and gut dysbiosis. PCOS has become one of the leading causes of female infertility worldwide. Recently, omega-3 polyunsaturated fatty acids (PUFAs) have been proven to benefit metabolic disorders in PCOS patients. However, its roles in the regulation of metabolic and endocrinal balances in PCOS pathophysiology are not clear. In the present study, we aimed to explore how omega-3 PUFAs alleviate ovarian dysfunction and insulin resistance in mice with dehydroepiandrosterone (DHEA)-induced PCOS by modulating the gut microbiota.

METHODS

We induced PCOS in female mice by injecting them with DHEA and then treated them with omega-3 PUFAs. 16S ribosomal DNA (rDNA) amplicon sequencing, fecal microbiota transplantation (FMT) and antibiotic treatment were used to evaluate the role of microbiota in the regulation of ovarian functions and insulin resistance (IR) by omega-3 PUFAs. To further investigate the mechanism of gut microbiota on omega-3-mediated ovarian and metabolic protective effects, inflammatory and oxidative stress markers in ovaries and thermogenic markers in subcutaneous and brown adipose tissues were investigated.

RESULTS

We found that oral supplementation with omega-3 PUFAs ameliorates the PCOS phenotype. 16S rDNA analysis revealed that omega-3 PUFA treatment increased the abundance of beneficial bacteria in the gut, thereby alleviating DHEA-induced gut dysbiosis. Antibiotic treatment and FMT experiments further demonstrated that the mechanisms underlying omega-3 benefits likely involve direct effects on the ovary to inhibit inflammatory cytokines such as IL-1β, TNF-α and IL-18. In addition, the gut microbiota played a key role in the improvement of adipose tissue morphology and function by decreasing multilocular cells and thermogenic markers such as Ucp1, Pgc1a, Cited and Cox8b within the subcutaneous adipose tissues.

CONCLUSION

These findings indicate that omega-3 PUFAs ameliorate androgen-induced gut microbiota dysbiosis. The gut microbiota plays a key role in the regulation of omega-3-mediated IR protective effects in polycystic ovary syndrome mice. Moreover, omega-3 PUFA-regulated improvements in the ovarian dysfunction associated with PCOS likely involve direct effects on the ovary to inhibit inflammation. Our findings suggest that omega-3 supplementation may be a promising therapeutic approach for the treatment of PCOS by modulating gut microbiota and alleviating ovarian dysfunction and insulin resistance.

Seasonal Variation in Gut Microbiota of the Wild Daurian Ground Squirrel (Spermophilus dauricus): Metagenomic Insights into Seasonal Breeding

The Spermophilus dauricus, the wild Daurian ground squirrel, is known to exhibit seasonal breeding behavior. Although the importance of gut microbiota in animal digestion, metabolism, and immunity is well-established, the correlation between gut microbiota and seasonal breeding in this species remains inadequately explored. In the present study, using metagenomic sequencing technology, the compositions and functions of the gut microbiota of wild Daurian ground squirrels in different breeding seasons were explored. The dominant gut microbial phyla were Firmicutes and Bacteroidetes. The Firmicutes were predominant in the breeding season, whereas Bacteroidetes were predominant in the non-breeding season. At the genus level, Lactobacillus accumulated during the breeding season, whereas Odoribacter and Alistipes increased during the non-breeding season. GO (Gene Ontology) and KEGG (Kyoto Encyclopedia of Genes and Genome) annotations indicated that genes in gut samples were highly associated with metabolic functions. The differential expression gene analysis showed that genes related to the phosphotransferase system, cysteine, and methionine metabolism were highly expressed during the breeding season, whereas the non-breeding season upregulated genes were enriched in starch and sucrose metabolism and bacterial chemotaxis pathways. In conclusion, this study could provide a reference for investigating gut microbiota in seasonal breeding animals and offer new insight into gut microbial function.

Dietary exposure to endocrine disruptors in gut microbiota: A systematic review

Endocrine disrupting chemicals (EDCs) can interfere with hormonal actions and have been associated with a higher incidence of metabolic disorders. They affect numerous physiological, biochemical, and endocrinal activities, including reproduction, metabolism, immunity, and behavior. The purpose of this review was to elucidate the association of EDCs in food with the gut microbiota and with metabolic disorders. EDC exposure induces changes that can lead to microbial dysbiosis. Products and by-products released by the microbial metabolism of EDCs can be taken up by the host. Changes in the composition of the microbiota and production of microbial metabolites may have a major impact on the host metabolism.

Berberine mitigates intracerebral hemorrhage-induced neuroinflammation in a gut microbiota-dependent manner in mice

BACKGROUND

Neuroinflammation is a frequent cause of brain damage after intracerebral hemorrhage (ICH). Gut microbiota are reported to regulate neuroinflammation. Berberine has been found to have anti-inflammatory actions, including in the central nervous system. However, it is not known whether berberine regulates neuroinflammation after ICH, nor is the relationship between the antineuroinflammatory actions of berberine and the gut microbiota after ICH understood.

METHODS

ICH was induced in male mice by collagenase injection. Immunofluorescent staining and quantitative real-time polymerase chain reaction (qRT-PCR) were performed to detect microglia/macrophage phenotypes. Immunofluorescent staining, ELISA, and FITC-dextran were conducted to determine gut function. 16S rRNA sequencing of the fecal material was conducted to determine alterations in the gut microbiota. Antibiotic cocktail treatment and fecal microbiota transplantation (FMT) were used to deplete or restore the gut microbiota, respectively. Cylinder, forelimb placement and wire hanging tests were conducted to evaluate neurobehavioral function.

RESULTS

Berberine significantly reduced neuroinflammation and alleviated neurological dysfunction by preventing microglial/macrophage proinflammatory polarization in ICH mice. Berberine also enhanced the function of the intestinal barrier, as shown by reductions in the levels of lipopolysaccharide-binding protein. Neuroinflammation in ICH mice was markedly reduced after transplantation of microbiota from berberine-treated mice, similar to treatment with oral berberine. In addition, a reduction in the microbiota reversed the neuroprotective effect of berberine.

CONCLUSIONS

Berberine is a potential treatment for ICH-induced neuroinflammation, and its effects are at least partially dependent on the gut microbiota.

SIRT3 ameliorates polycystic ovary syndrome through FOXO1/PGC-1α signaling pathway

BACKGROUND

Current studies have shown that Sirtuin3 (SIRT3) plays a key role in oocyte maturation. Polycystic ovary syndrome (PCOS) is a common disease caused by endocrine and metabolic abnormalities. The specific regulatory role and mechanism of SIRT3 in PCOS have not been reported.

METHODS

SIRT3 was overexpressed in dihydrotestosterone (DHT)-induced PCOS model in mice. Ovary morphology, serum hormone level, and apoptosis of tissue cells were detected. The expression of SIRT3/Forkhead box protein O1 (FOXO1)/peroxlsome proliferator-activated receptor-γ coactlvat-1α (PGC-1α)-related proteins was detected. Then SIRT3 was overexpressed in DHT-induced human granulosa-like tumor cell line KGN. After the detection of the pathway-associated proteins, PGC-1α specific inhibitor SR-18292 was added to detect cell apoptosis, mitochondrial membrane potential, mitochondrial ROS (MitoROS) levels, and other mitochondrial-related indicators RESULTS: The expression of SIRT3 in PCOS model was significantly decreased. Overexpression of SIRT3 could significantly improve ovarian morphology and serum sex hormone levels in DHT-induced PCOS mice and inhibit apoptosis both in vitro and in vivo. Overexpression of SIRT3 also could improve mitochondrial dysfunction in DHT-induced KGN cells via FOXO1/PGC-1α signaling pathway. And PGC-1α inhibitor SR-18292 reversed the protective effect of SIRT3 overexpression on apoptosis and mitochondrial function damage of DHT-induced KGN cells.

CONCLUSION

SIRT3 regulated FOXO1/PGC-1α signaling pathway to reduce mitochondrial dysfunction in PCOS, thereby improving PCOS.

Choline supplementation regulates gut microbiome diversity, gut epithelial activity, and the cytokine gene expression in gilts

Choline is an essential nutrient that is necessary for both fetal development and maintenance of neural function, while its effect on female ovarian development is largely unexplored. Our previous study demonstrated that choline supplementation promotes ovarian follicular development and ovulation, although its underlying mechanism was unclear. To uncover the potential regulation pathway, eighteen female Yorkshire × Landrace gilts were fed with either standard commercial diet (Control group, n = 9) or choline supplemented diet (Choline group, additional 500 mg/kg of control diet, n = 9) from day 90 of age to day 186. At day 186, feces samples were analyzed for effects on the gut microbiome using 16S ribosomal RNA gene V3-V4 region sequencing with Illumina MiSeq, serum samples were analyzed for trimethylamine (TMA) and trimethylamine-N-oxide (TMAO) using HILIC method, and jejunum tissues were analyzed for immune related gene expression using qRT-PCR. Our results show that choline supplementation did not alter the circulating level of TMA and TMAO (P > 0.05), but rather increased gut microbiome alpha diversity (P < 0.05). Beta diversity analysis results showed that the choline diet mainly increased the abundance of Firmicutes, Proteobacteria, and Actinobacteria, but decreased the abundance of Bacteroidetes, Spirochaetes, and Euryarchaeota at the phyla level. Meta-genomic analysis revealed that choline supplementation activated pathways in the gut microbiota associated with steroid hormone biosynthesis and degradation of infertility-causing environmental pollutants (bisphenol, xylene, and dioxins). To further verify the effect of choline on intestinal activity, a porcine intestine cell line (IPEC-J2) was treated with serial concentrations of choline chloride in vitro. Our data demonstrated that choline promoted the proliferation of IPEC-J2 while inhibiting the apoptotic activity. qRT-PCR results showed that choline significantly increased the expression level of Bcl2 in both IPEC-J2 cells and jejunum tissues. The expression of IL-22, a cytokine that has been shown to impact ovarian function, was increased by choline treatment in vitro. Our findings reveal the beneficial effect of choline supplementation on enhancing the gut microbiome composition and intestinal epithelial activity, and offer insights into how these changes may have contributed to the ovarian development-promoting effect we reported in our previous study.

Interplay of Gut Microbiota in Polycystic Ovarian Syndrome: Role of Gut Microbiota, Mechanistic Pathways and Potential Treatment Strategies

Polycystic Ovarian Syndrome (PCOS) comprises a set of symptoms that pose significant risk factors for various diseases, including type 2 diabetes, cardiovascular disease, and cancer. Effective and safe methods to treat all the pathological symptoms of PCOS are not available. The gut microbiota has been shown to play an essential role in PCOS incidence and progression. Many dietary plants, prebiotics, and probiotics have been reported to ameliorate PCOS. Gut microbiota shows its effects in PCOS via a number of mechanistic pathways including maintenance of homeostasis, regulation of lipid and blood glucose levels. The effect of gut microbiota on PCOS has been widely reported in animal models but there are only a few reports of human studies. Increasing the diversity of gut microbiota, and up-regulating PCOS ameliorating gut microbiota are some of the ways through which prebiotics, probiotics, and polyphenols work. We present a comprehensive review on polyphenols from natural origin, probiotics, and fecal microbiota therapy that may be used to treat PCOS by modifying the gut microbiota.

Bidirectional association between polycystic ovary syndrome and periodontal diseases

Polycystic ovary syndrome (PCOS) and periodontal disease (PDD) share common risk factors. The bidirectional interaction between PCOS and PDD has been reported, but until now, the underlying molecular mechanisms remain unclear. Endocrine disorders including hyperandrogenism (HA) and insulin resistance (IR) in PCOS disturb the oral microbial composition and increase the abundance of periodontal pathogens. Additionally, PCOS has a detrimental effect on the periodontal supportive tissues, including gingiva, periodontal ligament, and alveolar bone. Systemic low-grade inflammation status, especially obesity, persistent immune imbalance, and oxidative stress induced by PCOS exacerbate the progression of PDD. Simultaneously, PDD might increase the risk of PCOS through disturbing the gut microbiota composition and inducing low-grade inflammation and oxidative stress. In addition, genetic or epigenetic predisposition and lower socioeconomic status are the common risk factors for both diseases. In this review, we will present the latest evidence of the bidirectional association between PCOS and PDD from epidemiological, mechanistic, and interventional studies. A deep understanding on their bidirectional association will be beneficial to provide novel strategies for the treatment of PCOS and PDD.

The Implication of Mechanistic Approaches and the Role of the Microbiome in Polycystic Ovary Syndrome (PCOS): A Review

As a complex endocrine and metabolic condition, polycystic ovarian syndrome (PCOS) affects women's reproductive health. These common symptoms include hirsutism, hyperandrogenism, ovulatory dysfunction, irregular menstruation, and infertility. No one knows what causes it or how to stop it yet. Alterations in gut microbiota composition and disruptions in secondary bile acid production appear to play a causative role in developing PCOS. PCOS pathophysiology and phenotypes are tightly related to both enteric and vaginal bacteria. Patients with PCOS exhibit changed microbiome compositions and decreased microbial diversity. Intestinal microorganisms also alter PCOS patient phenotypes by upregulating or downregulating hormone release, gut-brain mediators, and metabolite synthesis. The human body's gut microbiota, also known as the "second genome," can interact with the environment to improve metabolic and immunological function. Inflammation is connected to PCOS and may be caused by dysbiosis in the gut microbiome. This review sheds light on the recently discovered connections between gut microbiota and insulin resistance (IR) and the potential mechanisms of PCOS. This study also describes metabolomic studies to obtain a clear view of PCOS and ways to tackle it.

The role of the sex hormone-gut microbiome axis in tumor immunotherapy

Accumulating evidence suggested that both gut microbiome and sex play a critical role in the efficacy of immune checkpoint blockade therapy. Considering the reciprocal relationship between sex hormones and gut microbiome, the sex hormone-gut microbiome axis may participate in the regulation of the response to immune checkpoint inhibitors (ICIs). In this review, it was attempted to summarize the current knowledge about the influences of both sex and gut microbiome on the antitumor efficacy of ICIs and describe the interaction between sex hormones and gut microbiome. Accordingly, this review discussed the potential of enhancing the antitumor efficacy of ICIs through regulating the levels of sex hormones through manipulation of gut microbiome. Collectively, this review provided reliable evidence concerning the role of the sex hormone-gut microbiome axis in tumor immunotherapy.

Roles of endoplasmic reticulum stress in the pathophysiology of polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder among reproductive-age women, affecting up to 15% of women in this group, and the most common cause of anovulatory infertility. Although its etiology remains unclear, recent research has revealed the critical role of endoplasmic reticulum (ER) stress in the pathophysiology of PCOS. ER stress is defined as a condition in which unfolded or misfolded proteins accumulate in the ER because of an imbalance in the demand for protein folding and the protein-folding capacity of the ER. ER stress results in the activation of several signal transduction cascades, collectively termed the unfolded protein response (UPR), which regulates various cellular activities. In principle, the UPR restores homeostasis and keeps the cell alive. However, if the ER stress cannot be resolved, it induces programmed cell death. ER stress has recently been recognized to play diverse roles in both physiological and pathological conditions of the ovary. In this review, we summarize current knowledge of the roles of ER stress in the pathogenesis of PCOS. ER stress pathways are activated in the ovaries of both a mouse model of PCOS and in humans, and local hyperandrogenism in the follicular microenvironment associated with PCOS is responsible for activating these. The activation of ER stress contributes to the pathophysiology of PCOS through multiple effects in granulosa cells. Finally, we discuss the potential for ER stress to serve as a novel therapeutic target for PCOS.

Effects of intestinal flora on polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a common endocrine disorder in women of reproductive age. Its clinical characteristics are mainly oligo-ovulation or anovulation, hyperandrogenemia (HA) and insulin resistance (IR). PCOS is considered to be one of the main causes of infertility in women of childbearing age, and its pathogenesis is still unclear. Intestinal flora, known as the "second genome" of human beings, is closely related to metabolic diseases, immune diseases and infectious diseases. At the same time, mounting evidence suggests that intestinal flora can regulate insulin synthesis and secretion, affect androgen metabolism and follicular development, and is involved in the occurrence of chronic inflammation and obesity. The imbalance of intestinal flora is caused by the abnormal interaction between intestinal flora and host cells caused by the change of intestinal microbial diversity, which is related to the occurrence and development of PCOS. The adjustment of intestinal flora may be a potential direction for the treatment of PCOS.

Effects of Yulin Tong Bu formula on modulating gut microbiota and fecal metabolite interactions in mice with polycystic ovary syndrome

BACKGROUND

Polycystic ovarian syndrome (PCOS) is a common endocrine disorder characterized by hyperandrogenism, ovarian dysfunction and polycystic ovarian morphology. Gut microbiota dysbiosis and metabolite are associated with PCOS clinical parameters. Yulin Tong Bu formula (YLTB), a traditional Chinese medicine formula, has been recently indicated to be capable of ameliorating polycystic ovary symptoms and correcting abnormal glucose metabolism. However, the therapeutic mechanism of YLTB on PCOS has not been fully elucidated.

METHODS

A pseudo sterile mouse model was established during this four-day acclimatization phase by giving the animals an antibiotic cocktail to remove the gut microbiota. Here, the therapeutic effects of YLTB on PCOS were investigated using dehydroepiandrosterone plus high-fat diet-induced PCOS mice model. Female prepuberal mice were randomly divided into three groups; namely, the control group, PCOS group and YLTB (38.68 g·kg^-1·day^-1) group. To test whether this effect is associated with the gut microbiota, we performed 16S rRNA sequencing studies to analyze the fecal microbiota of mice. The relationships among metabolites, gut microbiota, and PCOS phenotypes were further explored by using Spearman correlation analysis. Then, the effect of metabolite ferulic acid was then validated in PCOS mice.

RESULTS

Our results showed that YLTB treatment ameliorated PCOS features (ovarian dysfunction, delayed glucose clearance, decreased insulin sensitivity, deregulation of glucolipid metabolism and hormones, etc.) and significantly attenuated PCOS gut microbiota dysbiosis. Spearman correlation analysis showed that metabolites such as ferulic acid and folic acid are negatively correlated with PCOS clinical parameters. The effect of ferulic acid was similar to that of YLTB. In addition, the bacterial species such as Bacteroides dorei and Bacteroides fragilis were found to be positively related to PCOS clinical parameters, using the association study analysis.

CONCLUSION

These results suggest that YLTB treatment systematically regulates the interaction between the gut microbiota and the associated metabolites to ameliorate PCOS, providing a solid theoretical basis for further validation of YLTB effect on human PCOS trials.

The Importance of the Microbiota in Shaping Women’s Health—The Current State of Knowledge

According to current knowledge, a properly colonized human microbiota contributes to the proper functioning of the body. The composition of the natural flora changes depending on age, health, living conditions, and the use of antimicrobial agents: antibiotics, disinfectants, and some cosmetics. The human body is diversely populated with microorganisms and undergoes constant changes under the influence of various factors, and its proper composition is extremely important for the proper functioning of the body. Given the above, it was decided that we would review current scientific research that explains the cause–effect relationship between the composition of microorganisms populating the human body and health, focusing on women’s health. As a result, an overview paper was prepared based on 109 scientific sources from 2009–2022. Special attention was paid to the most recent scientific studies of the last five years, which account for more than 75% of the cited sources.

Gut and genital tract microbiomes: Dysbiosis and link to gynecological disorders

Every year, millions of women are affected by genital tract disorders, such as bacterial vaginosis (BV), endometrial cancer, polycystic ovary syndrome (PCOS), endometriosis, and uterine fibroids (UFs). These disorders pose a significant economic burden on healthcare systems and have serious implications for health and fertility outcomes. This review explores the relationships between gut, vaginal, and uterine dysbiosis and the pathogenesis of various diseases of the female genital tract. In recent years, reproductive health clinicians and scientists have focused on the microbiome to investigate its role in the pathogenesis and prevention of such diseases. Recent studies of the gut, vaginal, and uterine microbiomes have identified patterns in bacterial composition and changes across individuals' lives associated with specific healthy and diseased states, particularly regarding the effects of the estrogen-gut microbiome axis on estrogen-driven disorders (such as endometrial cancer, endometriosis, and UFs) and disorders associated with estrogen deficiency (such as PCOS). Furthermore, this review discusses the contribution of vitamin D deficiency to gut dysbiosis and altered estrogen metabolism as well as how these changes play key roles in the pathogenesis of UFs. More research on the microbiome influences on reproductive health and fertility is vital.

The Gut Microbiome and Female Health

The possession of two X chromosomes may come with the risk of various illnesses, females are more likely to be affected by osteoarthritis, heart disease, and anxiety. Given the reported correlations between gut microbiome dysbiosis and various illnesses, the female gut microbiome is worthy of exploration. Herein, we discuss the composition of the female gut microbiota and its dysbiosis in pathologies affecting the female population. Using PubMed, we performed a literature search, using key terms, namely: "gut microbiome", "estrogen", "menopause", "polycystic ovarian syndrome", "pregnancy", and "menstruation". In polycystic ovarian syndrome (PCOS), the abundance of Bacteroides vulgatus, Firmicutes, Streptococcus, and the ratio of Escherichia/Shigella was found to be increased while that of Tenericutes ML615J-28, Tenericutes 124-7, Akkermansia, Ruminococcaceae, and Bacteroidetes S24-7 was reduced. In breast cancer, the abundance of Clostridiales was enhanced, while in cervical cancer, Prevotella, Porphyromonas, and Dialister were enhanced but Bacteroides, Alistipes, and members of Lachnospiracea, were decreased. In ovarian cancer, Prevotella abundance was increased. Interestingly, the administration of Lactobacillus acidophilus, Bifidobacterium bifidum, Lactobacillus reuteri, and Lactobacillus fermentum ameliorated PCOS symptoms while that of a mix of Bifidobacterium lactis W51, Bifidobacterium bifidum W23, Lactobacillus brevis W63, Bifidobacterium lactis W52, Lactobacillus salivarius W24, Lactobacillus acidophilus W37, Lactococcus lactis W19, Lactobacillus casei W56, and Lactococcus lactis W58 alleviated vascular malfunction and arterial stiffness in obese postmenopausal women, and finally, while further research is needed, Prevotella maybe protective against postmenopausal bone mass loss. As several studies report the therapeutic potential of probiotics and since the gut microbiota of certain female pathological states has been relatively characterized, we speculate that the administration of certain bacterial species as probiotics is warranted, as novel independent or adjunct therapies for various female pathologies.

Polycystic Ovary Syndrome and Endometrial Cancer: A Scoping Review of the Literature on Gut Microbiota

Gut dysbiosis has been associated with polycystic ovary syndrome (PCOS) and endometrial cancer (EC) but no studies have investigated whether gut dysbiosis may explain the increased endometrial cancer risk in polycystic ovary syndrome. The aim of this scoping review is to evaluate the extent and nature of published studies on the gut microbiota in polycystic ovary syndrome and endometrial cancer and attempt to find any similarities between the composition of the microbiota. We searched for publications ranging from the years 2016 to 2022, due to the completion date of the ‘Human Microbiome Project’ in 2016. We obtained 200 articles by inputting keywords such as ‘gut microbiome’, ‘gut microbiota’, ‘gut dysbiosis’, ‘PCOS’, and ‘endometrial cancer’ into search engines such as PubMed and Scopus. Of the 200 identified in our initial search, we included 25 articles in our final review after applying the exclusion and inclusion criteria. Although the literature is growing in this field, we did not identify enough published studies to investigate whether gut dysbiosis may explain the increased EC risk in PCOS. Within the studies identified, we were unable to identify any consistent patterns of the microbiome similarly present in studies on women with PCOS compared with women with EC. Although we found that the phylum Firmicutes was similarly decreased in women with PCOS and studies on women with EC, there was however significant variability within the studies identified making it highly likely that this may have arisen by chance. Further research pertaining to molecular and microbiological mechanisms in relation to the gut microbiome is needed to elucidate a greater understanding of its contribution to the pathophysiology of endometrial cancer in patients with polycystic ovarian syndrome.