Association of Accelerometer-Determined Physical Activity and Sedentary Behavior With the Gut Microbiome in Middle-Aged Women: A Compositional Data Approach.

The beneficial effects of physical activity (PA) on gut microbiome have been reported, nevertheless the findings are inconsistent, with the main limitation of subjective methods for assessing PA. It is well accepted that using an objective assessment of PA reduces the measurement error and also allows objective assessment of sedentary behavior (SB). We aimed to study the associations between accelerometer-assessed behaviors (i.e., SB, light-intensity physical activity [LPA] and moderate-to-vigorous physical activity [MVPA]) with the gut microbiome using compositional data analysis, a novel approach that enables to study these behaviors accounting for their inter-dependency. This cross-sectional study included 289 women from the Northern Finland Birth Cohort 1966. Physical activity was measured during 14 days by wrist-worn accelerometers. Analyses based on the combined effect of MVPA and SB, and compositional data analyses in association with the gut microbiome data were performed. The microbial alpha- and beta-diversity were not significantly different between the MVPA-SB groups, and no differentially abundant microorganisms were detected. Compositional data analysis did not show any significant associations between any movement behavior (relative to the others) on microbial alpha-diversity. Butyrate-producing bacteria such as Agathobacter and Lachnospiraceae CAG56 were significantly more abundant when reallocating time from LPA or SB to MVPA (γ = 0.609 and 0.113, both p-values = 0.007). While PA and SB were not associated with microbial diversity, we found associations of these behaviors with specific gut bacteria, suggesting that PA of at least moderate intensity (i.e., MVPA) could increase the abundance of short-chain fatty acid-producing microbes.

Gut microbiome in endometriosis: a cohort study on 1000 individuals.

BACKGROUND: Endometriosis, defined as the presence of endometrial-like tissue outside of the uterus, is one of the most prevalent gynecological disorders. Although different theories have been proposed, its pathogenesis is not clear. Novel studies indicate that the gut microbiome may be involved in the etiology of endometriosis; nevertheless, the connection between microbes, their dysbiosis, and the development of endometriosis is understudied. This case-control study analyzed the gut microbiome in women with and without endometriosis to identify microbial targets involved in the disease. METHODS: A subsample of 1000 women from the Estonian Microbiome cohort, including 136 women with endometriosis and 864 control women, was analyzed. Microbial composition was determined by shotgun metagenomics and microbial functional pathways were annotated using the Kyoto Encyclopedia of Genes and Genomes (KEGG) database. Partitioning Around Medoids (PAM) algorithm was performed to cluster the microbial profile of the Estonian population. The alpha- and beta-diversity and differential abundance analyses were performed to assess the gut microbiome (species and KEGG orthologies (KO)) in both groups. Metagenomic reads were mapped to estrobolome-related enzymes' sequences to study potential microbiome-estrogen metabolism axis alterations in endometriosis. RESULTS: Diversity analyses did not detect significant differences between women with and without endometriosis (alpha-diversity: all p-values > 0.05; beta-diversity: PERMANOVA, both R 2 < 0.0007, p-values > 0.05). No differential species or pathways were detected after multiple testing adjustment (all FDR p-values > 0.05). Sensitivity analysis excluding women at menopause (> 50 years) confirmed our results. Estrobolome-associated enzymes' sequence reads were not significantly different between groups (all FDR p-values > 0.05). CONCLUSIONS: Our findings do not provide enough evidence to support the existence of a gut microbiome-dependent mechanism directly implicated in the pathogenesis of endometriosis. To the best of our knowledge, this is the largest metagenome study on endometriosis conducted to date.

Physical activity, sedentary behavior and microbiome: A systematic review and meta-analysis.

BACKGROUND: The effects of physical activity and sedentary behavior on human health are well known, however, the molecular mechanisms are poorly understood. Growing evidence points to physical activity as an important modulator of the composition and function of microbial communities, while evidence of sedentary behavior is scarce. We aimed to synthesize and meta-analyze the current evidence about the effects of physical activity and sedentary behavior on microbiome across different body sites and in different populations. METHODS: A systematic search in PubMed, Web of Science, Scopus and Cochrane databases was conducted until September 2022. Random-effects meta-analyses including cross-sectional studies (active vs. inactive/athletes vs. non-athletes) or trials reporting the chronic effect of physical activity interventions on gut microbiome alpha-diversity in healthy individuals were performed. RESULTS: Ninety-one studies were included in this systematic review. Our meta-analyses of 2632 participants indicated no consistent effect of physical activity on microbial alpha-diversity, although there seems to be a trend toward a higher microbial richness in athletes compared to non-athletes. Most of studies reported an increase in short-chain fatty acid-producing bacteria such as Akkermansia, Faecalibacterium, Veillonella or Roseburia in active individuals and after physical activity interventions. CONCLUSIONS: Physical activity levels were positively associated with the relative abundance of short-chain fatty acid-producing bacteria. Athletes seem to have a richer microbiome compared to non-athletes. However, high heterogeneity between studies avoids obtaining conclusive information on the role of physical activity in microbial composition. Future multi-omics studies would enhance our understanding of the molecular effects of physical activity and sedentary behavior on the microbiome.

Beyond the reproductive tract: gut microbiome and its influence on gynecological health.

PURPOSE OF REVIEW: The analysis of microbiome in association with female health is today a "hot topic" with the main focus on microbes in the female reproductive tract. Nevertheless, recent studies are providing novel information of the possible influence of the gut microbiome on gynecological health outcomes, especially as we start to understand that the gut microbiome is an extended endocrine organ influencing female hormonal levels. This review summarizes the current knowledge of the gut microbes in association with gynecological health. RECENT FINDINGS: The gut microbiome has been associated with endometriosis, polycystic ovary syndrome, gynecological cancers, and infertility, although there is a lack of consistency and consensus among studies due to different study designs and protocols used, and the studies in general are underpowered. SUMMARY: The interconnection between the gut microbiome and reproductive health is complex and further research is warranted. The current knowledge in the field emphasizes the link between the microbiome and gynecological health outcomes, with high potential for novel diagnostic and treatment tools via modulation of the microenvironment.

Beyond the reproductive tract: gut microbiome and its influence on gynecological health.

PURPOSE OF REVIEW: The analysis of microbiome in association with female health is today a "hot topic" with the main focus on microbes in the female reproductive tract. Nevertheless, recent studies are providing novel information of the possible influence of the gut microbiome on gynecological health outcomes, especially as we start to understand that the gut microbiome is an extended endocrine organ influencing female hormonal levels. This review summarizes the current knowledge of the gut microbes in association with gynecological health. RECENT FINDINGS: The gut microbiome has been associated with endometriosis, polycystic ovary syndrome, gynecological cancers, and infertility, although there is a lack of consistency and consensus among studies due to different study designs and protocols used, and the studies in general are underpowered. SUMMARY: The interconnection between the gut microbiome and reproductive health is complex and further research is warranted. The current knowledge in the field emphasizes the link between the microbiome and gynecological health outcomes, with high potential for novel diagnostic and treatment tools via modulation of the microenvironment.

Comparative efficacy of exercise, diet and/or pharmacological interventions on BMI, ovulation, and hormonal profile in reproductive-aged women with overweight or obesity: a systematic review and network meta-analysis.

BACKGROUND: The increasing prevalence of obesity worldwide poses a significant threat to reproductive function owing, in part, to hormonal disturbances caused by negative feedback between excess adiposity and the hypothalamic-pituitary-ovarian axis. Consequently, finding the most appropriate strategies to lose weight and improve ovulation in women with overweight or obesity is a clinically relevant matter that needs to be investigated. A comprehensive comparison of the independent and combined efficacy of lifestyle and/or pharmacological interventions on BMI, ovulation, and hormonal profile in women with overweight or obesity at risk of anovulatory infertility would facilitate improving fertility strategies in this population. OBJECTIVE AND RATIONALE: This study aimed to evaluate the comparative efficacy of exercise, diet, and pharmacological interventions on BMI, ovulation, and hormonal profile in reproductive-aged women with overweight or obesity. SEARCH METHODS: A systematic review was performed by searching PubMed, Scopus, Web of Science, PsycINFO, and Cochrane Library up to 14 December 2023, for randomized controlled trials assessing the effects of exercise, diet and/or pharmacological interventions (i.e. weight-lowering drugs or ovulation inducers) on BMI, ovulation, and/or hormonal profile in reproductive-aged women with overweight or obesity. We performed frequentist random-effect network meta-analyses and rated the certainty of the evidence. The primary outcomes were BMI and ovulation rate, and the secondary outcomes were serum reproductive hormone levels (gonadotrophins, androgens, or oestrogens). We performed sensitivity analyses, including the studies that only involved women with PCOS. OUTCOMES: Among 1190 records screened, 148 full texts were assessed for eligibility resulting in 95 trials (9910 women), of which 53% presented a high or unclear risk of bias. The network meta-analyses revealed that, compared to control: diet combined with weight-lowering drugs (mean difference (MD) -2.61 kg/m2; 95% CI -3.04 to -2.19; τ2 = 0.22) and adding exercise (MD -2.35 kg/m2; 95% CI -2.81 to -1.89; τ2 = 0.22) led to the greatest decrease in BMI; exercise combined with diet and ovulation inducers (risk ratio (RR) 7.15; 95% CI 1.94-26.40; τ2 = 0.07) and exercise combined with diet and weight-lowering drugs (RR 4.80; 95% CI 1.67-13.84; τ2 = 0.07) produced the highest increase in ovulation rate; and exercise combined with diet and weight-lowering drugs was the most effective strategy in reducing testosterone levels (standardized mean difference (SMD) -2.91; 95% CI -4.07 to -1.74; τ2 = 2.25), the third most effective strategy in increasing sex hormone-binding globulin levels (SMD 2.37; 95% CI 0.99-3.76; τ2 = 2.48), and it was coupled with being ranked first in terms of free androgen index reduction (SMD -1.59; 95% CI -3.18 to 0.01; τ2 = 1.91). The surface under the cumulative ranking curve scores suggested that: diet combined with weight-lowering drugs is the strategy most likely (94%) to produce the highest BMI reduction; and exercise combined with diet and ovulation inducers is the strategy most likely (89%) to produce the highest ovulation rate improvement. The sensitivity analyses, which exclusively included studies involving women diagnosed with PCOS, were consistent with the results presented above. WIDER IMPLICATIONS: Overall, the findings of this network meta-analysis indicate that the combination of exercise, diet, and pharmacological interventions is effective for weight loss, improving ovulation, and normalizing the androgen levels of women with overweight or obesity. Although higher quality studies are needed, these results support that the optimal treatment strategy for women with overweight or obesity wishing to conceive must consider exercise, diet, and pharmacological interventions during the shared decision-making process.

The endometrial transcriptome of infertile women with and without implantation failure.

INTRODUCTION: Implantation failure after transferring morphologically "good-quality" embryos in in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) may be explained by impaired endometrial receptivity. Analyzing the endometrial transcriptome analysis may reveal the underlying processes and could help in guiding prognosis and using targeted interventions for infertility. This exploratory study investigated whether the endometrial transcriptome profile was associated with short-term or long-term implantation outcomes (ie success or failure). MATERIAL AND METHODS: Mid-luteal phase endometrial biopsies of 107 infertile women with one full failed IVF/ICSI cycle, obtained within an endometrial scratching trial, were subjected to RNA-sequencing and differentially expressed genes analysis with covariate adjustment (age, body mass index, luteinizing hormone [LH]-day). Endometrial transcriptomes were compared between implantation failure and success groups in the short term (after the second fresh IVF/ICSI cycle) and long term (including all fresh and frozen cycles within 12 months). The short-term analysis included 85/107 women (33 ongoing pregnancy vs 52 no pregnancy), excluding 22/107 women. The long-term analysis included 46/107 women (23 'fertile' group, ie infertile women with a live birth after ≤3 embryos transferred vs 23 recurrent implantation failure group, ie no live birth after ≥3 good quality embryos transferred), excluding 61/107 women not fitting these categories. As both analyses drew from the same pool of 107 samples, there was some sample overlap. Additionally, cell type enrichment scores and endometrial receptivity were analyzed, and an endometrial development pseudo-timeline was constructed to estimate transcriptomic deviations from the optimum receptivity day (LH + 7), denoted as ΔWOI (window of implantation). RESULTS: There were no significantly differentially expressed genes between implantation failure and success groups in either the short-term or long-term analyses. Principal component analysis initially showed two clusters in the long-term analysis, unrelated to clinical phenotype and no longer distinct following covariate adjustment. Cell type enrichment scores did not differ significantly between groups in both analyses. However, endometrial receptivity analysis demonstrated a potentially significant displacement of the WOI in the non-pregnant group compared with the ongoing pregnant group in the short-term analysis. CONCLUSIONS: No distinct endometrial transcriptome profile was associated with either implantation failure or success in infertile women. However, there may be differences in the extent to which the WOI is displaced.

To transfer or not to transfer: the dilemma of mosaic embryos - a narrative review.

A frequent finding after preimplantation genetic diagnostic testing for aneuploidies using next-generation sequencing is an embryo that is putatively mosaic. The prevalence of this outcome remains unclear and varies with technical and external factors. Mosaic embryos can be classified by the percentage of cells affected, type of chromosome involvement (whole or segmental), number of affected chromosomes or affected cell type (inner mass cell, trophectoderm or both). The origin of mosaicism seems to be intrinsic as a post-zygotic mitotic error, but some external factors can play a role. As experience has increased with the transfer of mosaic embryos, clinical practice has gradually become more flexible in recent years. Nevertheless, clinical results show lower implantation, pregnancy and clinical pregnancy rates and higher miscarriage rates with mosaic embryo transfer when compared with the transfer of euploid embryos. Prenatal diagnosis is highly recommended after the transfer of mosaic embryos. This narrative review is intended to serve as reference material for practitioners in reproductive medicine who must manage a mosaic embryo result after preimplantation genetic testing for aneuploidies.

An unbiased approach of molecular characterization of the endometrium: toward defining endometrial-based infertility.

Infertility is a complex condition affecting millions of couples worldwide. The current definition of infertility, based on clinical criteria, fails to account for the molecular and cellular changes that may occur during the development of infertility. Recent advancements in sequencing technology and single-cell analysis offer new opportunities to gain a deeper understanding of these changes. The endometrium has a potential role in infertility and has been extensively studied to identify gene expression profiles associated with (impaired) endometrial receptivity. However, limited overlap among studies hampers the identification of relevant downstream pathways that could play a role in the development of endometrial-related infertility. To address these challenges, we propose sequencing the endometrial transcriptome of healthy and infertile women at the single-cell level to consistently identify molecular signatures. Establishing consensus on physiological patterns in endometrial samples can aid in identifying deviations in infertile patients. A similar strategy has been used with great success in cancer research. However, large collaborative initiatives, international uniform protocols of sample collection and processing are crucial to ensure reliability and reproducibility. Overall, the proposed approach holds promise for an objective and accurate classification of endometrial-based infertility and has the potential to improve diagnosis and treatment outcomes.

A systematic review identifying seminal plasma biomarkers and their predictive ability on IVF and ICSI outcomes.

The diverse nature and high molecule concentration of seminal plasma (SP) makes this fluid a good potential source for a potential biomarker that could predict assisted reproductive technology (ART) outcomes. Currently, semen quality parameters cannot accurately predict ART outcomes. A systematic literature search was conducted to identify human SP biomarkers with potential predictive ability for the outcomes of IVF and intracytoplasmic sperm injection. Observational cohort and case-control studies describing the association between biomarkers in human SP and the outcome of infertile men attending for ART were included. Forty-three studies were selected, reporting on 89 potential SP biomarkers (grouped as oxidative stress, proteins glycoproteins, metabolites, immune system components, metals and trace elements and nucleic acids). The present review supports 32 molecules in SP as potentially relevant biomarkers for predicting ART outcomes; 23 molecules were reported once and nine molecules were reported in more than one study; IL-18 and TGF-ß1-IL-18 ratio were confirmed in distinct studies. This review presents the most comprehensive overview of relevant SP biomarkers to predict ART outcomes to date, which is of clinical interest for infertility investigations and assisted reproduction; nevertheless, its potential is under-exploited. This review could serve as starting point for designing an all-encompassing study for biomarkers in SP and their predictive ability for ART outcomes, and for developing a non-invasive diagnostic tool.

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.

Microenvironment of the Lower Reproductive Tract: Focus on the Cervical Mucus Plug.

The female lower reproductive tract microbiota is a complex ecosystem comprising various microorganisms that play a pivotal role in maintaining women's reproductive well-being. During pregnancy, the vaginal microbiota undergoes dynamic changes that are important for a successful gestation. This review summarizes the implications of the cervical mucus plug microenvironment and its profound impact on reproductive health. Further, the symbiotic relationship between the vaginal microbiome and the cervical mucus plug is highlighted, with a special emphasis on how this natural barrier serves as a guardian against ascending infections. Understanding this complex host-microbes interplay could pave the way for innovative approaches to improve women's reproductive health and fertility.