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Gut Microbial β-Glucuronidase Activity in Polycystic Ovary Syndrome (PCOS)​​

• Published: 2023

• Source: Scientific Reports

• Study Design: Case-control study involving women diagnosed with PCOS and healthy controls. Feacal samples were analyzed to measure β-glucuronidase and β-glucosidase activities, alongside assessments of hormone levels and clinical parameters.

• Findings: Women with PCOS exhibited significantly higher β-glucuronidase activity compared to controls. A positive correlation was observed between β-glucuronidase activity and serum testosterone levels.

• Key Insights: Elevated gut microbial β-glucuronidase activity may contribute to hormonal imbalances in PCOS by influencing estrogen and androgen metabolism.

 

Endometrial Dysbiosis and Estrobolome Alteration in Infertility​​

• Published: 2024

• Source: Biomolecules

• Study Design: Observational study involving women with infertility and repeated implantation failure. Endometrial biopsies were analyzed for β-glucuronidase activity, estrogen receptor expression, and inflammatory markers.

• Findings: Increased β-glucuronidase activity and estrogen receptor β expression were observed in the endometrial tissue of women with dysbiosis. A decrease in beneficial Lactobacilli was also noted.

• Key Insights: Endometrial dysbiosis, characterized by elevated β-glucuronidase activity, may impair estrogen signaling and contribute to infertility and implantation failure.

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​Menopause Is Associated with an Altered Gut Microbiome and Microbial Metabolite Profile​

Published: 2022

Source: mSystems (Journal published by the American Society for Microbiology)

Study Design: This was a comparative, cross-sectional study analysing gut microbiome profiles in premenopausal and postmenopausal women, with additional comparison to male microbiome profiles. The researchers used 16S rRNA gene sequencing to examine microbial composition and diversity, focusing on changes associated with menopausal status.

Findings:

• Reduced microbial diversity was observed in postmenopausal women compared to premenopausal women.

• There was a notable shift toward a male-like gut microbiome profile post-menopause.

• Specific estrogen-metabolising and beneficial bacteria were found in lower abundance in postmenopausal women.

Key Insights:

• Menopause is associated with measurable changes in gut microbiota composition, likely influenced by hormonal shifts, especially declining estrogen levels.

• The decrease in anti-inflammatory and metabolic bacteria —could have implications for metabolic health, immunity, and hormone regulation in postmenopausal women.

• Testing for these bacteria can help inform personalised gut health interventions during and after the menopausal transition.

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Gut Microbiota Imbalance and Its Correlations With Hormone and Inflammatory Factors in Endometriosis​

Published: 2021
Source: Archives of Gynaecology and Obstetrics

 

Study Design

• What: A case‑control observational human study comparing gut microbiota composition, dysbiosis, and serum hormone levels in women with advanced endometriosis vs. healthy controls.

• Where: Human participants (12 endometriosis patients and 12 controls) provided fecal samples for microbiome sequencing and blood samples for hormone and cytokine measurements.

• When: Data collected before 2021, published in that year.

• How:

  • Used 16S rRNA gene sequencing to profile gut bacterial communities.

  • Measured serum estradiol (E2) and inflammatory markers like IL‑8 in blood.

  • Correlated microbial taxa abundances with hormone and inflammation levels.

Findings

• Dysbiosis & Diversity: Women with endometriosis had lower gut microbial diversity and an altered Firmicutes/Bacteroidetes ratio compared to healthy controls.

• Hormone Correlations: Serum estradiol (E2) levels were significantly higher in the endometriosis group. Specific bacteria (e.g., Blautia and Dorea) correlated with estradiol levels, linking microbial imbalance to hormone variations.

• Functional Shifts: The microbiota in endometriosis patients was enriched in functions related to endocrine system processing and inflammatory pathways.

Key Insights

• Dysbiosis & Hormones: This study provides direct human evidence that gut microbiome imbalance (dysbiosis) is associated with altered systemic hormone levels (higher estradiol) in a reproductive endocrinological disorder.

• Potential Mechanisms: Associations between specific bacterial taxa and hormones suggest that microbial imbalance may influence estrogen metabolism or signaling in endometriosis.

• Translational Value: These findings highlight the potential of targeting the microbiome to modulate hormone‑related conditions in women.

 

Gut Microbiota Dysbiosis in Polycystic Ovary Syndrome (PCOS)​

Published: 2025 (systematic clinical evidence synthesis; includes multiple human studies)
Source: Frontiers in Endocrinology

Study Design

• What: A clinical synthesis and observational analysis focusing on gut microbiota dysbiosis and its relationship to hormonal imbalance in women diagnosed with PCOS vs. healthy controls.

• Where: Multiple human cohorts (e.g., PCOS vs. control groups from different research centres) were included.

• When: Published in 2025.

• How:

  • Gut microbial profiles were assessed using 16S rRNA gene sequencing to quantify diversity and composition differences.

  • Associations between gut microbiome dysbiosis and clinical hormone measures (especially androgens and insulin‑related hormones) were analysed.

  • Synthesized data from several PCOS studies to identify consistent dysbiosis patterns.

Findings

• Dysbiosis Pattern: Women with PCOS commonly exhibited reduced microbial diversity and imbalanced bacterial taxa, including altered Firmicutes/Bacteroidetes ratios and changes in beneficial vs. pathogenic bacteria.

• Hormonal Associations: Gut microbiota imbalance correlated with hyperandrogenism (higher circulating androgens) and insulin resistance, both hallmark hormonal disturbances in PCOS.

• Metabolic Links: Dysbiosis was also linked with altered short‑chain fatty acid production and bile acid metabolism, which are known to influence hormone regulation.

Key Insights

• Microbiome–Hormone Dysregulation: Distinct dysbiosis profiles in PCOS are repeatedly associated with hormonal imbalances such as increased androgens and disrupted metabolic hormones.

• Bidirectional Interplay: These associations support the idea that gut microbial imbalance may contribute to endocrine dysregulation seen in human PCOS, not just metabolic symptoms.

• Research Importance: Highlights that targeting microbiome composition could be a future avenue for modulating hormone disturbances in PCOS.

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