Metagenomic analysis identified microbiome alterations and pathological association between intestinal microbiota and polycystic ovary syndrome

The evolution of our understanding of human development over the last 10 years

As it fulfills an irresistible need to understand our own origins, research on human development occupies a unique niche in scientific and medical research. In this Comment, we explore the progress in our understanding of human development over the past 10 years. The focus is on basic research, clinical applications, and ethical considerations.

Differences in the individual curative effect of acupuncture for obese women with polycystic ovary syndrome based on metagenomic analysis: study protocol for a randomized controlled trial

BACKGROUND

Polycystic ovary syndrome is a common cause of infertility and shows a high incidence in women of reproductive age. Acupuncture is an appropriate adjunctive treatment for PCOS. However, the add-on effect of acupuncture as an adjunctive treatment for obese women with PCOS has not been studied, and previous studies indicate that there are individual differences in the curative effect of acupuncture, while deeper research on the mechanism of differences in the individual curative effect of acupuncture for obese women with PCOS is still lacking. This trial aims to assess the add-on treatment efficacy of acupuncture for obese women with PCOS and to explore the role of the gut microbiome on the differences in the individual curative effect of acupuncture based on metagenomic analysis.

METHODS/DESIGN

This is an open-label, randomized, controlled trial. A total of 86 obese women with PCOS will be recruited. Subjects will be randomly assigned to a study group and a control group in a 1:1 ratio, with 43 subjects in each group (10 patients from each group who meet the study criteria will participate in the metagenomic analysis). An additional 10 subjects who meet the study criteria will be recruited to a healthy control group. The study group will receive acupuncture and clomiphene citrate treatment; the control group will only receive clomiphene citrate. Acupuncture treatment will be conducted three times a week from the fifth day of menstruation or withdrawal bleeding until the start of the next menstruation, for up to three menstrual cycles. The primary outcome will be LH/FSH. The secondary outcomes will comprise biometric features, hormone biomarkers, metabolic biomarkers, inflammatory biomarkers, Self-Rating Anxiety Scale, Self-Rating Depression Scale, and metagenomic analysis. The outcomes will be measured at baseline and post-intervention. Data will be analyzed using SPSS 19.0, and the gut microbiome will be analyzed using metagenomic analysis.

DISCUSSION

In this study, we are evaluating the add-on effects of acupuncture and exploring the mechanism of the differences in the individual curative effect of acupuncture based on the gut microbiome, which may provide evidence to explain the different outcomes of different trials on acupuncture for PCOS and hopefully to provide a new aspect to study the mechanism of acupuncture's treatment effect.

TRIAL REGISTRATION

Chinese Clinical Trial Registry ChiCTR2000029882 . Registered on 16 February 2020.

Reduced stress-associated FKBP5 DNA methylation together with gut microbiota dysbiosis is linked with the progression of obese PCOS patients

Polycystic ovary syndrome (PCOS) is a common endocrine disease in females that is characterized by hyperandrogenemia, chronic anovulation, and polycystic ovaries. However, the exact etiology and pathogenesis of PCOS are still unknown. The aim of this study was to clarify the bacterial, stress status, and metabolic differences in the gut microbiomes of healthy individuals and patients with high body mass index (BMI) PCOS (PCOS-HB) and normal BMI PCOS (PCOS-LB), respectively. Here, we compared the gut microbiota characteristics of PCOS-HB, PCOS-LB, and healthy controls by 16S rRNA gene sequencing, FK506-binding protein 5 (FKBP5) DNA methylation and plasma metabolite determination. Clinical parameter comparisons indicated that PCOS patients had higher concentrations of total testosterone, androstenedione, dehydroepiandrosterone sulfate, luteinizing hormone, and HOMA-IR while lower FKBP5 DNA methylation. Significant differences in bacterial diversity and community were observed between the PCOS and healthy groups but not between the PCOS-HB and PCOS-LB groups. Bacterial species number was negatively correlated with insulin concentrations (both under fasting status and 120 min after glucose load) and HOMA-IR but positively related to FKBP5 DNA methylation. Compared to the healthy group, both PCOS groups had significant changes in bacterial genera, including Prevotella_9, Dorea, Maihella, and Slackia, and plasma metabolites, including estrone sulfate, lysophosphatidyl choline 18:2, and phosphatidylcholine (22:6e/19:1). The correlation network revealed the complicated interaction of the clinical index, bacterial genus, stress indices, and metabolites. Our work links the stress responses and gut microbiota characteristics of PCOS disease, which might afford perspectives to understand the progression of PCOS.

β-Sitosterol Ameliorates Endometrium Receptivity in PCOS-Like Mice: The Mediation of Gut Microbiota

Background: Polycystic ovary syndrome (PCOS), one of the most common endocrine diseases in women of childbearing age, has been found to be accompanied by changes in the gut microbiota. The Bu Shen Yang Xue formula (BSYXF) is a traditional Chinese medicine widely used for the treatment of PCOS. This study aimed to investigate whether the protective effects of β-sitosterol, the main active ingredient of BSYXF, on PCOS was mediated by regulating gut microbiota.

Methods: The presence of β-sitosterol in BSYXF was detected by liquid chromatography-mass spectrometry. The PCOS-like mouse model was induced by dehydroepiandrosterone. The fecal supernatant of β-sitosterol-treated mice was prepared for fecal microbiota transplantation (FMT). Body weight and wet weight of the uterus and ovary of the mice were recorded for organ index calculation. Hematoxylin and eosin stain was used to assess the endometrial morphology and microenvironment changes. Expression of endometrial receptivity markers cyclooxygenase-2 (COX-2), Integrin ανβ3, leukemia inhibitory factor (LIF), and homeobox A10 (HOXA10) in the endometrium were determined by immunohistochemistry and western blot analysis. Enzyme-linked immunosorbent assay was employed to detect the expression of follicle stimulating hormone (FSH), luteinizing hormone (LH), progesterone (P), and testosterone (T) in the serum. The diversity of gut microbiota was examined by 16S rDNA gene sequencing.

Results: With the treatment of β-sitosterol and β-sitosterol-FMT, the uterine index of PCOS-like mice increased, the ovarian index decreased, levels of COX-2, LH and T decreased, and levels of Integrin ανβ3, LIF, HOXA10, FSH, and P increased. Under β-sitosterol treatment, the structure of the gut microbiota in PCOS-like mice was also changed.

Conclusion: β-sitosterol regulates the endometrial receptivity of PCOS and harmonizes the sex hormone balance, which may be related to the changes in the structure and composition of gut microbiota, thus affecting the pathological process of PCOS.

16S rDNA Full-Length Assembly Sequencing Technology Analysis of Intestinal Microbiome in Polycystic Ovary Syndrome

Objective

To study the characteristics and relationship of the gut microbiota in patients with polycystic ovary syndrome (PCOS).

Method

We recruited 45 patients with PCOS and 37 healthy women from the Reproductive Department of Shengjing Hospital. We recorded their clinical indexes, and sequenced their fecal samples by 16S rDNA full-length assembly sequencing technology (16S-FAST).

Result

We found decreased α diversity and different abundances of a series of microbial species in patients with PCOS compared to healthy controls. We found LH and AMH were significantly increased in PCOS with Prevotella enterotype when compared to control women with Prevotella enterotype, while glucose and lipid metabolism level remained no significant difference, and situations were opposite in PCOS and control women with Bacteroides enterotype. Ruminococcus gnavus, Prevotella stercorea, Dialister succinatiphilus and Bacteroides fragilis were more abundant while Christensenellaceae spp. were less abundant in the PCOS group. P. stercorea was significantly more prevalent in PCOS-not insulin resistance (NIR) compared to control-NIR and PCOS-not overweight (NOW) patient groups compared to control-NOW groups. Kyoto Encyclopedia Genes and Genomes reflecting pathways related to lipopolysaccharide biosynthesis were more abundant in the PCOS group.

Conclusion

Our study found gut microbiota that had different abundance in patients with PCOS compared to healthy controls. An intimate relationship was shown between the gut microbiota and pathological changes in PCOS. We suggest the gut microbiota should be taken into consideration in the treatment of symptoms of PCOS via drugs and diet.

Androgen-induced gut dysbiosis disrupts glucolipid metabolism and endocrinal functions in polycystic ovary syndrome

BACKGROUND

The characteristics of polycystic ovary syndrome (PCOS), a common reproductive endocrinal disorder, are high incidence, complicated aetiology and poor therapeutic effects. PCOS patients frequently exhibit gut dysbiosis; however, its roles in the regulation of metabolic and endocrinal balances in PCOS pathophysiology are not clear.

RESULTS

In this study, gut dysbiosis was reproduced in dehydroepiandrosterone (DHEA)-induced PCOS-like rats. An antibiotic cocktail was used to eliminate gut microbiota during DHEA treatment; however, depletion of the gut microbiota did not prevent the occurrence of PCOS phenotypes in DHEA-treated rats. DHEA-shaped gut microbiota transplanted to pseudo germ-free recipients trigged disturbances in hepatic glucolipid metabolism and reproductive hormone imbalance. The clinical features of PCOS may be correlated with the relative abundance of gut microbes and the levels of faecal metabolites in faecal microbiota transplantation (FMT) recipient rats.

CONCLUSION

These findings indicate that androgen-induced gut microbiota dysbiosis may aggravate metabolic and endocrinal malfunction in PCOS. Video Abstract.

Polycystic ovary syndrome: Pathways and mechanisms for possible increased susceptibility to COVID-19

In 75% of women with polycystic ovary syndrome (PCOS), insulin action is impaired. In obesity, visceral adipose tissue becomes dysfunctional: Chronic inflammation is favored over storage, contributing to the development of metabolic complications. PCOS, metabolic syndrome (MetSy) and non-alcoholic fatty liver disease (NAFLD) apparently share common pathogenic factors; these include abdominal adiposity, excess body weight and insulin resistance. Alterations in the gut microbiome have been noted in women with PCOS compared to controls; these may lead to deterioration of the intestinal barrier, increased gut mucosal permeability and immune system activation, hyperinsulinemia and glucose intolerance, which hamper normal ovarian function and follicular development (all being hallmarks of PCOS). It has been proposed that PCOS may entail higher susceptibility to coronavirus disease 2019 (COVID-19) via its associated comorbidities (NAFLD, obesity, MetSy and alterations in the gut microbiome). Studies have found an association between acute respiratory distress syndrome (seen in severe cases of COVID-19) and the intestinal microbiome. Furthermore, apparently, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can gain entry to the gastrointestinal tract via locally-expressed angiotensin converting enzyme type 2 receptors. Excess body weight is associated with more severe COVID-19 and increased mortality. Although robust links between SARS-CoV-2 infection and PCOS/NAFLD/gut microbiome/metabolic consequences are yet to be confirmed, it seems that strategies for adapting the intestinal microbiome could help reduce the severity of COVID-19 in women with PCOS with or without NAFLD, MetSy or obesity.

The Gut Microbiome in Polycystic Ovary Syndrome and Its Association with Metabolic Traits

CONTEXT

Despite the gut microbiome being widely studied in metabolic diseases, its role in polycystic ovary syndrome (PCOS) has been scarcely investigated.

OBJECTIVE

Compare the gut microbiome in late fertile age women with and without PCOS and investigate whether changes in the gut microbiome correlate with PCOS-related metabolic parameters.

DESIGN

Prospective, case-control study using the Northern Finland Birth Cohort 1966.

SETTING

General community.

PARTICIPANTS

A total of 102 PCOS women and 201 age- and body mass index (BMI)-matched non-PCOS control women. Clinical and biochemical characteristics of the participants were assessed at ages 31 and 46 and analyzed in the context of gut microbiome data at the age of 46.

INTERVENTION

(s): None.

MAIN OUTCOME MEASURE(S)

Bacterial diversity, relative abundance, and correlations with PCOS-related metabolic measures.

RESULTS

Bacterial diversity indices did not differ significantly between PCOS and controls (Shannon diversity P = .979, unweighted UniFrac P = .175). Four genera whose balance helps to differentiate between PCOS and non-PCOS were identified. In the whole cohort, the abundance of 2 genera from Clostridiales, Ruminococcaceae UCG-002, and Clostridiales Family XIII AD3011 group, were correlated with several PCOS-related markers. Prediabetic PCOS women had significantly lower alpha diversity (Shannon diversity P = .018) and markedly increased abundance of genus Dorea (false discovery rate = 0.03) compared with women with normal glucose tolerance.

CONCLUSION

PCOS and non-PCOS women at late fertile age with similar BMI do not significantly differ in their gut microbial profiles. However, there are significant microbial changes in PCOS individuals depending on their metabolic health.

Intersection of Polycystic Ovary Syndrome and the Gut Microbiome

The etiology of polycystic ovary syndrome (PCOS) remains unclear, although studies indicate that both genetic and environmental factors contribute to the syndrome. In 2012, Tremellen and Pearce proposed the idea that dysbiosis of the intestinal (gut) microbiome is a causative factor of metabolic and reproductive manifestations of PCOS. In the past 5 years, studies in both humans and rodent models have demonstrated that changes in the taxonomic composition of gut bacteria are associated with PCOS. Studies have also clearly shown that these changes in gut microbiota are associated with PCOS as opposed to obesity, since these changes are observed in women with PCOS that are both of a normal weight or obese, as well as in adolescent girls with PCOS and obesity compared with body mass index- and age-matched females without the disorder. Additionally, studies in both women with PCOS and rodent models of PCOS demonstrated that hyperandrogenism is associated with gut microbial dysbiosis, indicating that androgens may modulate the gut microbial community in females. One study reported that the fecal microbiome transplantation of stool from women with PCOS or exposure to certain bacteria resulted in a PCOS-like phenotype in mice, while other studies showed that exposure to a healthy gut microbiome, pre/probiotics, or specific gut metabolites resulted in protection from developing PCOS-like traits in mice. Altogether, these results suggest that dysbiosis of the gut microbiome may be sufficient to develop PCOS-like symptoms and that modulation of the gut microbiome may be a potential therapeutic target for PCOS.

Role of gut microbiota in epigenetic regulation of colorectal Cancer

Colorectal cancer (CRC) remains one of the most commonly diagnosed cancers and a leading cause of cancer-related deaths worldwide. The stepwise accumulation of epigenetic alterations in the normal colorectal epithelium has been reported to act as a driving force for the initiation and promotion of tumorigenesis in CRC. From a mechanistic standpoint, emerging evidence indicates that within the colorectal epithelium, the diverse gut microbiota can interact with host cells to regulate multiple physiological processes. In fact, recent studies have found that the gut microbiota represents a potential cause of carcinogenesis, invasion, and metastasis via DNA methylation, histone modifications, and non-coding RNAs - providing an epigenetic perspective for the connection between the gut microbiota and CRC. Herein, we comprehensively review the recent research that provides a comprehensive yet succinct evidence connecting the gut microbiota to CRC at an epigenetic level, including carcinogenic mechanisms of cancer-related microbiota, and the potential for utilizing the gut microbiota as CRC biomarkers. These scientific findings highlight a promising future for manipulating the gut microbiota to improve clinical outcomes in patients suffering from CRC.