Evaluation of a natural S-equol supplement in treating premenstrual symptoms and the effect of the gut microbiota: An open-label pilot study

Perspective on the Coevolutionary Role of Host and Gut Microbiota in Polyphenol Health Effects: Metabotypes and Precision Health

"Personalized nutrition" aims to establish nutritional strategies to improve health outcomes for non-responders. However, it is utopian since most people share similar nutritional requirements. "Precision health," encompassing lifestyles, may be more fitting. Dietary (poly)phenols are "healthy" but non-nutritional molecules (thus, we can live without them). The gut microbiota influences (poly)phenol effects, producing metabolites with different activity than their precursors. Furthermore, producing distinctive metabolites, like urolithins, lunularin, and equol, leads to the term "polyphenol-related gut microbiota metabotypes," grouping individuals based on a genuine microbial metabolism of ellagic acid, resveratrol, and isoflavones, respectively. Additionally, (poly)phenols exert prebiotic-like effects through their antimicrobial activities, typically reducing microbial diversity and modulating microbiota functionality by impacting its composition and transcriptomics. Since the gut microbiota perceives (poly)phenols as a threat, (poly)phenol effects are mostly a consequence of microbiota adaptation through differential (poly)phenol metabolism (e.g., distinctive reductions, dehydroxylations, etc.). This viewpoint is less prosaic than considering (poly)phenols as essential nutritional players in human health, yet underscores their health significance in a coevolutionary partnership with the gut microbiota. In the perspective on the gut microbiota and (poly)phenols interplay, microbiota metabotypes could arbiter health effects. An innovative aspect is also emphasized: modulating the interacting microbial networks without altering the composition.

Gut microbiota-generated metabolites: missing puzzles to hosts' health, diseases, and aging

The gut microbiota, an intricate community of bacteria residing in the gastrointestinal system, assumes a pivotal role in various physiological processes. Beyond its function in food breakdown and nutrient absorption, gut microbiota exerts a profound influence on immune and metabolic modulation by producing diverse gut microbiota-generated metabolites (GMGMs). These small molecules hold potential to impact host health via multiple pathways, which exhibit remarkable diversity, and have gained increasing attention in recent studies. Here, we elucidate the intricate implications and significant impacts of four specific metabolites, Urolithin A (UA), equol, Trimethylamine N-oxide (TMAO), and imidazole propionate, in shaping human health. Meanwhile, we also look into the advanced research on GMGMs, which demonstrate promising curative effects and hold great potential for further clinical therapies. Notably, the emergence of positive outcomes from clinical trials involving GMGMs, typified by UA, emphasizes their promising prospects in the pursuit of improved health and longevity. Collectively, the multifaceted impacts of GMGMs present intriguing avenues for future research and therapeutic interventions. [BMB Reports 2024; 57(5): 207-215].

Effect of nutritional interventions on the psychological symptoms of premenstrual syndrome in women of reproductive age: a systematic review of randomized controlled trials

CONTEXT

Premenstrual syndrome (PMS) affects approximately 48% of women of reproductive age worldwide. It can lead to functional impairment, lower quality of life, and decreased work productivity. Despite the availability of medical treatment options, women are seeking alternative interventions because of concerns of harmful side effects and limited evidence of efficacy associated with pharmacological treatments. To date, high-quality research investigating the effects of dietary and nutrient intervention on PMS is limited.

OBJECTIVE

This systematic review investigated the effect of nutritional interventions on the psychological symptoms of PMS.

DATA SOURCES

Five electronic databases were searched for randomized controlled trials (RCTs) published in English from inception to October 2022. Trials eligible for inclusion were nutritional intervention studies involving women of reproductive age that measured PMS-associated psychological outcomes.

DATA EXTRACTION

Articles were selected using prespecified inclusion criteria. Data screening and extraction and risk-of-bias assessments were conducted by 3 independent reviewers using article screening software and the Cochrane Risk of Bias 2 tool.

DATA ANALYSIS

Thirty-two articles reporting on 31 RCTs involving 3254 participants, ranging in age from 15 to 50 years were included and narratively reviewed. Only 1 of the included studies had a low risk of bias. Treatment with vitamin B6, calcium, and zinc consistently had significant positive effects on the psychological symptoms of PMS. There was insufficient evidence to support the effects of vitamin B1, vitamin D, whole-grain carbohydrates, soy isoflavones, dietary fatty acids, magnesium, multivitamin supplementation, or PMS-specific diets.

CONCLUSIONS

There is some evidence to support the use of nutritional interventions for improving psychological symptoms of PMS. However, more research using consistent protocols, procedures to minimize risk of bias, intention-to-treat analysis, and clearer reporting is required to provide conclusive nutritional recommendations for improving PMS-related psychological outcomes.

PROSPERO REGISTRATION NO

CRD42022369999.

The Japanese Version of the Daily Record of Severity of Problems for Premenstrual Symptoms: Reliability and Validity Among the General Japanese Population

Purpose

The validity and reliability of the Japanese version of the Daily Record of Severity of Problems (DRSP-J) have already been confirmed in a population with premenstrual symptoms. This study aimed to assess the validity and reliability of the DRSP-J in the general population.

Patients and Methods

We analyzed data from 113 Japanese women with regular menstrual cycles who applied to participate in an ongoing study. Participants were recruited regardless of the severity of premenstrual symptoms, and their menstrual cycles were monitored using the DRSP-J for two cycles. Reliability was examined using Cronbach's α, a measure of internal consistency, and test-retest reliability. Structural validity was assessed using a principal component analysis (PCA). The Hospital Anxiety and Depression Scale (HADS) and EuroQol-5 Dimensions-5 Levels (EQ-5D-5L) were used to examine concurrent validity. The agreement between the clinical diagnoses based on the diagnostic criteria for premenstrual syndrome/premenstrual dysphoric disorder and that based on the DRSP-J score was examined using the kappa coefficient.

Results

Cronbach's α for DRSP-J total score was 0.96. The DRSP-J total score showed high test-retest reliability. The PCA showed a two-factor model describing "Mood" and "Behavior/Physical" symptoms. The DRSP-J total score was highly correlated with the HADS total and EQ-5D-5L scores. The classification of "moderate to severe premenstrual syndrome" and "premenstrual dysphoric disorder" by clinical methods and the criteria based on the DRSP-J were in good agreement (kappa values = 0.78).

Conclusion

The DRSP-J is a reliable and valid measure of premenstrual symptoms in the general Japanese population, including those with few or no symptoms.

Isoflavones Effects on Vascular and Endothelial Outcomes: How Is the Gut Microbiota Involved?

Isoflavones are a group of (poly)phenols, also defined as phytoestrogens, with chemical structures comparable with estrogen, that exert weak estrogenic effects. These phytochemical compounds have been targeted for their proven antioxidant and protective effects. Recognizing the increasing prevalence of cardiovascular diseases (CVD), there is a growing interest in understanding the potential cardiovascular benefits associated with these phytochemical compounds. Gut microbiota may play a key role in mediating the effects of isoflavones on vascular and endothelial functions, as it is directly implicated in isoflavones metabolism. The findings from randomized clinical trials indicate that isoflavone supplementation may exert putative effects on vascular biomarkers among healthy individuals, but not among patients affected by cardiometabolic disorders. These results might be explained by the enzymatic transformation to which isoflavones are subjected by the gut microbiota, suggesting that a diverse composition of the microbiota may determine the diverse bioavailability of these compounds. Specifically, the conversion of isoflavones in equol-a microbiota-derived metabolite-seems to differ between individuals. Further studies are needed to clarify the intricate molecular mechanisms behind these contrasting results.

Enterogenic metabolomics signatures of depression: what are the possibilities for the future

INTRODUCTION

An increasing number of studies indicate that the microbiota-gut-brain axis is an important pathway involved in the onset and progression of depression. The responses of the organism (or its microorganisms) to external cues cannot be separated from a key intermediate element: their metabolites.

AREAS COVERED

In recent years, with the rapid development of metabolomics, an increasing amount of metabolites has been detected and studied, especially the gut metabolites. Nevertheless, the increasing amount of metabolites described has not been reflected in a better understanding of their functions and metabolic pathways. Moreover, our knowledge of the biological interactions among metabolites is also incomplete, which limits further studies on the connections between the microbial-entero-brain axis and depression.

EXPERT OPINION

This paper summarizes the current knowledge on depression-related metabolites and their involvement in the onset and progression of this disease. More importantly, this paper summarized metabolites from the intestine, and defined them as enterogenic metabolites, to further clarify the function of intestinal metabolites and their biochemical cross-talk, providing theoretical support and new research directions for the prevention and treatment of depression.

New insights on the impact of gut microbiota on premenstrual disorders. Will probiotics solve this mystery?

Premenstrual disorders (PMDs) refer to premenstrual syndrome (PMS) and premenstrual dysphoric disorder (PMDD), where both are characterized by physical and psychological changes occurring in the luteal phase of menstrual cycle. According to the available theories, there is no single accusation succeeded to explain the pathophysiology of PMDs. However, there is emerging evidence for the role of gut microbiota (GM) in PMDs, supported by the diverging impact of GM on our body systems. The direct secretory function of GM and their integration in hormonal, neurotransmitters and bioactive compounds secretion and activity reinforce this speculation. Moreover, the bidirectional relation between GM and steroid hormones and the impact of diet, drugs, and inflammation on both, GM and PMDs incidence and severity justify the need for more studies to determine the actual role of GM in PMDs and the possible potential of probiotics and prebiotics as therapeutic options.

Phytoestrogens and Health Effects

Phytoestrogens are literally estrogenic substances of plant origin. Although these substances are useful for plants in many aspects, their estrogenic properties are essentially relevant to their predators. As such, phytoestrogens can be considered to be substances potentially dedicated to plant-predator interaction. Therefore, it is not surprising to note that the word phytoestrogen comes from the early discovery of estrogenic effects in grazing animals and humans. Here, several compounds whose activities have been discovered at nutritional concentrations in animals and humans are examined. The substances analyzed belong to several chemical families, i.e., the flavanones, the coumestans, the resorcylic acid lactones, the isoflavones, and the enterolignans. Following their definition and the evocation of their role in plants, their metabolic transformations and bioavailabilities are discussed. A point is then made regarding their health effects, which can either be beneficial or adverse depending on the subject studied, the sex, the age, and the physiological status. Toxicological information is given based on official data. The effects are first presented in humans. Animal models are evoked when no data are available in humans. The effects are presented with a constant reference to doses and plausible exposure.

Development and Psychometric Testing of a New Short-Form of the Premenstrual Symptoms Questionnaire (PSQ-S)

Purpose

The Premenstrual Symptoms Questionnaire (PSQ) is a patient-reported outcome measurement tool for premenstrual symptoms. Although the PSQ is a very useful tool with 14 items to screen for a wide variety of premenstrual symptoms, not everyone will respond to all the questions. Fewer questions would be less burdensome on the respondents. We aimed to develop and analyze the psychometric properties of a short-form of the PSQ (PSQ-S).

Patients and Methods

The study participants were from an earlier study with a sample of 1388 female students. We reanalyzed data collected from 922 students with regular menstrual cycles who completed the PSQ, premenstrual dysphoric disorder (PMDD) scale, Somatic Symptom Scale-8 (SSS-8), and numerical rating scale (NRS) for menstrual pain. First, we selected nine items for the PSQ-S based on the results of the corrected item-total correlation analysis. The PSQ-S was then analyzed for reliability and validity using the classical test theory. Moreover, item response theory was applied to test the psychometric properties of the PSQ-S.

Results

Cronbach's α for the PSQ-S score was 0.93. Principal component factor analysis revealed a one-factor model. Confirmatory factor analysis showed that the one-factor model was a good fit. The PSQ-S total score was strongly correlated with the PSQ total score, PMDD scale score, and SSS-8 score (r=0.978, 0.854, and 0.648, respectively) and moderately correlated with the NRS (r=0.437). Item response theory analyses showed that the constructs and items of the PSQ-S had satisfactory discrimination, difficulty parameters, item information curves, and test information curves. Receiver operating characteristic curve analysis revealed a cut-off score of ≥22 for suspected premenstrual disorders based on the total PSQ-S score.

Conclusion

The PSQ-S, consisting of nine items from the PSQ, had sufficient reliability and validity and could be a convenient assessment tool for premenstrual symptoms in routine clinical practice.