Metagenomic analysis of the microbiome of the upper reproductive tract: combating ovarian cancer through predictive, preventive, and personalized medicine

Linking reproductive tract microbiota to premature ovarian insufficiency: Pathophysiological mechanisms and therapies

Over the past decade, research on the human microbiota has become a hot topic. Among them, the female reproductive tract (FRT) also has a specific microbiota that maintains the body's health and dynamic balance, especially in the reproductive aspect. When the FRT ecosystem is dysregulated, changes in immune and metabolic signals can lead to pathological and physiological changes such as chronic inflammation, epithelial barrier disruption, changes in cell proliferation and apoptosis, and dysregulation of angiogenesis and metabolism, thereby causing disruption of the female endocrine system. Premature ovarian insufficiency (POI), a clinical syndrome of ovarian dysfunction, is primarily influenced by immune, genetic, and environmental factors. New evidence suggests that dysbiosis of the FRT microbiota and/or the presence of specific bacteria may contribute to the occurrence and progression of POI. This influence occurs through both direct and indirect mechanisms, including the regulation of estrogen metabolism. The use of probiotics or microbiota transplantation to regulate the microbiome has also been proven to be beneficial in improving ovarian function and the quality of life in women with premature aging. This article provides an overview of the interrelationships and roles between the FRT microbiome and POI in recent years, to fully understand the risk factors affecting female reproductive health, and to offer insights for the future diagnosis, treatment, and application of the FRT microbiome in POI patients.

The ovarian cancer-associated microbiome contributes to the tumor's inflammatory microenvironment

A growing body of research has established a correlation between tumors and persistent chronic inflammatory infiltration. As a primary instigator of inflammation, the majority of microbiomes naturally residing within our bodies engage in a mutually beneficial symbiotic relationship. Nevertheless, alterations in the microbiome's composition or breaches in the normal barrier function can disrupt the internal environment's homeostasis, potentially leading to the development and progression of various diseases, including tumors. The investigation of tumor-related microbiomes has contributed to a deeper understanding of their role in tumorigenesis. This review offers a comprehensive overview of the microbiome alterations and the associated inflammatory changes in ovarian cancer. It may aid in advancing research to elucidate the mechanisms underlying the ovarian cancer-associated microbiome, providing potential theoretical support for the future development of microbiome-targeted antitumor therapies and early screening through convenient methods.

The intratumoral microbiota biomarkers for predicting survival and efficacy of immunotherapy in patients with ovarian serous cystadenocarcinoma

BACKGROUND

Ovarian serous cystadenocarcinoma, accounting for about 90% of ovarian cancers, is frequently diagnosed at advanced stages, leading to suboptimal treatment outcomes. Given the malignant nature of the disease, effective biomarkers for accurate prediction and personalized treatment remain an urgent clinical need.

METHODS

In this study, we analyzed the microbial contents of 453 ovarian serous cystadenocarcinoma and 68 adjacent non-cancerous samples. A univariate Cox regression model was used to identify microorganisms significantly associated with survival and a prognostic risk score model constructed using LASSO Cox regression analysis. Patients were subsequently categorized into high-risk and low-risk groups based on their risk scores.

RESULTS

Survival analysis revealed that patients in the low-risk group had a higher overall survival rate. A nomogram was constructed for easy visualization of the prognostic model. Analysis of immune cell infiltration and immune checkpoint gene expression in both groups showed that both parameters were positively correlated with the risk level, indicating an increased immune response in higher risk groups.

CONCLUSION

Our findings suggest that microbial profiles in ovarian serous cystadenocarcinoma may serve as viable clinical prognostic indicators. This study provides novel insights into the potential impact of intratumoral microbial communities on disease prognosis and opens avenues for future therapeutic interventions targeting these microorganisms.

Metagenomic analysis revealed the association between gut microbiota and different ovary responses to controlled ovarian stimulation

The aim of this study was to assess the correlation between gut microbial taxonomy and various ovarian responses to controlled ovarian stimulation. A total of 22 IVF cycles with a follicle-to-oocyte index (FOI) < 0.5 and 25 IVF cycles with FOI ≥ 0.5 were included in this study. Baseline demographic characteristics were compared between the two groups. Metagenomic sequencing was performed to analyze fecal microbial community profiles. Mice were used to evaluate the effect of Bifidobacterium_longum on ovarian response to stimulation. Compared with FOI < 0.5 group, women in group with FOI ≥ 0.5 had significant more oocytes retrieved (p < 0.01). Prevotella_copri, Bateroides_vulgatus, Escherichia_coli and Bateroides_stercoris were more abundant in FOI < 0.5 group while Bifidobacterium_longum, Faecalibacterium_prausnitzii, Ruminococcus_gnavus and Bifidobacterium_pseudocatenula were more abundant in FOI ≥ 0.5 group. After adjusting for women's age and BMI, Pearson correlation analysis indicated alteration of gut microbiome was related with serum E2, FSH, number of oocytes retrieved and clinical pregnancy rate. Animal study showed ovarian response will be improved after Bifidobacterium_longum applied. An increased abundance of Bacteroidetes and Prevotella copri, as well as a decreased abundance of Bifidobacterium longum, have been found to be associated with poor ovarian responsiveness. Changes in gut microbiomes have been observed to be correlated with certain clinical characteristics. The potential enhancement of ovarian response may be facilitated by the integration of Bifidobacterium longum.

Genital tract microbiota composition profiles and use of prebiotics and probiotics in gynaecological cancer prevention: review of the current evidence, the European Society of Gynaecological Oncology prevention committee statement

Female genital tract (FGT) microbiota has been associated with the development of gynaecological cancers. Thus, the possibility of whether manipulation of the FGT microbiota can help in the prevention of disease should be investigated. Various prebiotics, probiotics, and other non-clinician prescribed agents have been reported to have therapeutic effects in cervical disease. Numerous studies have reported an association between human papillomavirus infection and subsequent cervical dysplasia and a decrease in the abundance of Lactobacillus species. A continuum of microbiota composition is observed from the vagina to the upper parts of the FGT, but no evidence suggests that manipulation of the vaginal microbiota can help to modify the composition of other FGT compartments. Although prebiotics and probiotics have been reported to be beneficial, the studies are small and of varying design, and high-quality evidence to support their use is lacking. Currently, no studies have examined these therapeutics in other gynaecological malignancies. Thus, recommendation of probiotics, prebiotics, or other over-the-counter supplements for the prevention of gynaecological cancers warrants larger, well designed studies.

The Role of the Human Microbiome in Epithelial Ovarian Cancer

Ovarian cancer is the fifth-leading cause of cancer deaths among women due to the absence of available screening methods to identify early disease. Thus, prevention and early disease detection investigations are of high priority, surrounding a critical window of opportunity to better understand important pathogenic mechanisms of disease progression. Microorganisms modulate molecular interactions in humans that can influence states of health and disease, including ovarian cancer. While the mechanisms of infectious microbial invasion that trigger the immune-inflammatory axis are well studied in cancer research, the complex interactions that promote the transition of noninfectious healthy microbes to pathobiont expansion are less understood. As traditional research has focused on the influences of infectious pathogens on ovarian cancer development and progression, the impact of noninfectious microbes has gained scientific attention. The objective of this chapter is to summarize current evidence on the role of microbiota in epithelial ovarian cancer throughout disease.

Role of the intratumoral microbiome in tumor progression and therapeutics implications

Microbes are widely present in various organs of the human body and play important roles in numerous physiological and pathological processes. Nevertheless, owing to multiple limiting factors, such as contamination and low biomass, the current understanding of the intratumoral microbiome is limited. The intratumoral microbiome exerts tumor-promoting or tumor-suppressive effects by engaging in metabolic reactions within the body, regulating signaling cancer-related pathways, and impacting both host cells function and immune system. It is important to emphasize that intratumoral microbes exhibit substantial heterogeneity in terms of composition and abundance across various tumor types, thereby potentially influencing diverse aspects of tumorigenesis, progression, and metastasis. These findings suggest that intratumoral microbiome have great potential as diagnostic and prognostic biomarkers. By manipulating the intratumoral microbes to employ cancer therapy, the efficacy of chemotherapy or immunotherapy can be enhanced while minimizing adverse effects. In this review, we comprehensively describe the composition and function of the intratumoral microbiome in various human solid tumors. Combining recent advancements in research, we discuss the origins, mechanisms, and prospects of the clinical applications of intratumoral microbiome.

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.

COVID-19 lessons to protect populations against future pandemics by implementing PPPM principles in healthcare

The coronavirus disease 2019 (COVID-19) pandemic has continued for more than 3 years, placing a huge burden on society worldwide. Although the World Health Organization (WHO) has declared an end to COVID-19 as a Public Health Emergency of International Concern (PHEIC), it is still considered a global threat. Previously, there has been a long debate as to whether the COVID-19 emergency will eventually end or transform into a more common infectious disease from a PHEIC, and how should countries respond to similar pandemics in the future more time-efficiently and cost-effectively. We reviewed the past, middle and current situation of COVID-19 based on bibliometric analysis and epidemiological data. Thereby, the necessity is indicated to change the paradigm from reactive healthcare services to predictive, preventive and personalised medicine (PPPM) approach, in order to effectively protect populations against COVID-19 and any future pandemics. Corresponding measures are detailed in the article including the involvement of multi-professional expertise, application of artificial intelligence, rapid diagnostics and patient stratification, and effective protection, amongst other to be considered by advanced health policy.