Age-Related Changes, Influencing Factors, and Crosstalk Between Vaginal and Gut Microbiota: A Cross-Sectional Comparative Study of Pre- and Postmenopausal Women

Urinary equol and equol-predicting microbial species are favorably associated with body fat measures among Chinese adults

BACKGROUND

Many studies have investigated the intake of dietary isoflavones in relation to obesity risk, while the association using objective biomarkers of isoflavones, particularly equol (a gut-derived metabolite of daidzein with greater bioavailability than other isoflavones) has been less studied. In addition, the associations between equol and gut microbiota profile at population level remain to be fully characterized.

OBJECTIVE

We aimed to identify equol-predicting microbial species and to investigate the associations of equol-predicting microbial species and urinary excretion of isoflavones including glycitein, genistein, daidzein, and equol with diverse obesity markers in free living-individuals.

METHODS

In this 1-year longitudinal study of 754 community-dwelling adults, urinary isoflavones, fecal microbiota, height, weight, and circumferences of waist and hip were measured at baseline and again after 1-year. Liver fat [indicated by controlled attenuation parameter (CAP)] and other body composition were also measured after 1-year. Linear models and linear mixed-effects models were used to analyze the associations for single measure and repeated measures, respectively.

RESULTS

Among 305 participants (median age: 50 y, IQR: 37-59 y) including 138 men and 167 women, higher urinary excretion of equol was associated with lower CAP (β = -0.013, P < 0.001) and body fat mass (β= -0.014, P = 0.046). No association was found between any other urinary isoflavones and obesity markers (all P>0.05). We identified 21 bacterial genera whose relative abundance were positively associated with urinary equol concentrations (all Pfalsediscovery rate < 0.05), and constructed an equol-predicting microbial score to reflect the overall equol-producing potential of host gut microbiota. This score was inversely associated with CAP (β = -0.040, P = 0.011).

CONCLUSIONS

High urinary equol concentrations and equol-predicting microbial species could be favorably associated with liver fat and other obesity markers.

Cervicovaginal specimen biomarkers for early detection of ovarian and endometrial cancer: A review

BACKGROUND

In the last decade, technical innovations have resulted in the development of several minimally invasive diagnostic cancer tools. Within women at high risk of developing ovarian or endometrial cancer (EC) due to hereditary cancer syndrome, there is an urgent need for minimally invasive and patient-friendly methods to detect ovarian cancer and EC at an early stage.

MATERIALS AND METHODS

We performed a systematic search of studies using DNA methylation or mutation analysis, microbiome, or proteomics performed on cervicovaginal specimens (smear, swab, or tampon) intended to detect ovarian and EC published until January 2024.

RESULTS

Included studies (n = 36) showed high heterogeneity in terms of biomarkers used and outcomes, and only a few studies reported on the detection of biomarkers in high-risk subgroups.

CONCLUSION

Based on the findings in this review, DNA methylation techniques seem to be the most promising for detecting ovarian and EC at early stages in the general population. Future validation of cervicovaginal DNA methylation techniques is needed to determine whether this technique might be beneficial in hereditary high-risk subgroups.

Microbiome-based precision nutrition: Prebiotics, probiotics and postbiotics

Microorganisms have been used in nutrition and medicine for thousands of years worldwide, long before humanity knew of their existence. It is now known that the gut microbiota plays a key role in regulating inflammatory, metabolic, immune and neurobiological processes. This text discusses the importance of microbiota-based precision nutrition in gut permeability, as well as the main advances and current limitations of traditional probiotics, new-generation probiotics, psychobiotic probiotics with an effect on emotional health, probiotic foods, prebiotics, and postbiotics such as short-chain fatty acids, neurotransmitters and vitamins. The aim is to provide a theoretical context built on current scientific evidence for the practical application of microbiota-based precision nutrition in specific health fields and in improving health, quality of life and physiological performance.

Comparison of the five different definitions of equol producers: The relationship between blood and urine equol concentrations and blood parameters in 466 healthy men and women

BACKGROUND AND AIMS

No studies have compared various definitions of "equol producers" until now. Therefore, we aimed to explore the accuracy of five different definitions of equol producers (EQP) and their associations with health benefits.

METHODS

This is a cross-sectional study of 466 healthy Japanese men and women aged between 22 and 88 years. Equol producer proportions were calculated from their serum and urine isoflavone concentrations using five commonly used definitions. We then examined their accuracy, and associations with the blood parameters.

RESULTS

Proportions of equol ranged from 29 % in the most stringent definition to 47.6 % in the most sensitive definition. EQP identified under all definitions had significantly low serum PSA1 levels compared to nonequol producers (NEQP). The most stringent definition, which is defined as the urinary equol level of 1.0 μM and above, corresponded to the highest median serum equol level and was associated with better health outcomes. Male EQP identified by this definition seemed to have reduced risk of LDL2-hypercholesterolemia by 50 %, and female EQP identified by this definition seemed to have lower risk of high hs-CRP,3 compared to NEQP. Both the first and second stringent definition, which is defined as the serum equol level of 1.0 ng/mL and above, was associated with lower thyroid stimulating hormone level.

CONCLUSIONS

More stringent definitions were associated with better parameters in general. Combined with the dietary inquires, a reliable definition for equol producer is crucial to evaluate the health benefits of equol.

The effect of the female genital tract and gut microbiome on reproductive dysfunction

Microorganisms are ubiquitous in the human body; they are present in various areas including the gut, mouth, skin, respiratory tract, and reproductive tract. The interaction between the microbiome and reproductive health has become an increasingly compelling area of study. Disruption of the female genital tract microbiome can significantly impact the metabolism of amino acids, carbohydrates, and lipids, increasing susceptibility to reproductive tract diseases such as vaginitis, chronic endometritis, endometrial polyps, endometriosis, and polycystic ovary syndrome. The gut microbiome, considered an endocrine organ, plays a crucial role in the reproductive endocrine system by interacting with hormones like estrogen and androgens. Imbalances in the gut microbiome composition can lead to various diseases and conditions, including polycystic ovary syndrome, endometriosis, and cancer, although research on their mechanisms remains limited. This review highlights the latest advancements in understanding the female genital tract and gut microbiomes in gynecological diseases. It also explores the potential of microbial communities in the treatment of reproductive diseases. Future research should focus on identifying the molecular mechanisms underlying the association between the microbiome and reproductive diseases to develop new and effective strategies for disease prevention, diagnosis, and treatment related to female reproductive organs.

The role of microbiota in the management of genitourinary syndrome of menopause

It is estimated that the 25-50% of women who are reaching menopause every year report symptoms related to the genitourinary syndrome of menopause (GSM). The symptoms are not due simply to lack of estrogen. One possible contributing cause of symptoms is the vaginal microbiota. The vaginal microbiota is a dynamic entity and plays a critical role in the pathogenic interplay of postmenopausal changes. Treatment of this syndrome depends on the severity and type of the symptoms and on the preferences and expectations of women. As there are many treatment options, therapy should be individualized. While new evidence on the role of Lactobacilli in premenopause is emerging, the role of Lactobacilli is still unclear in GSM and the impact of microbiota on vaginal health remains conflictual. However, some reports show promising data on the effect of probiotic therapy in menopause. In the literature there are few studies and small population samples on the role of an exclusive therapy with Lactobacilli and further data will be mandatory. Studies involving large numbers of patients and different intervention periods will be necessary to obtain evidence of the preventive and curative role of vaginal probiotics.

Menopausal Changes in the Microbiome-A Review Focused on the Genitourinary Microbiome

A balanced interaction between the host and its microbiome is crucial to health. Research regarding the significance of the gut and vaginal microbiomes in female health is substantial. However, less data regarding the urinary microbiome are available. Interactions between the gut, vaginal, and urinary microbiomes are also currently being researched. Hormone-induced dysbiosis after menopause is believed to have effects on physical changes and health consequences. Postmenopausal changes in the gut microbiome are associated with increased short-chain fatty acids and hydrogen sulfide levels. Increased vaginal pH caused by reduced estrogen alters the vaginal microbiome, resulting in reduced levels of Lactobacillus. Such changes influence the vaginal structure and functions, contributing to the onset of genitourinary syndrome of menopause. A dysbiosis of the urinary microbiome is associated with urgency and urinary incontinence and also related to interstitial cystitis/bladder pain syndrome and neuropathic bladder. As these diseases commonly affect postmenopausal women, hormone-induced changes in the microbiome may play a role. Menopause increases the alpha diversity of the urinary microbiome and lowers the percentage of Lactobacillus in urine, and such changes precede recurrent cystitis. More research regarding the effects of changes in the urinary microbiome due to menopause on urinary tract diseases is needed.