Effectiveness of natural S-equol supplement for premenstrual symptoms: protocol of a randomised, double-blind, placebo-controlled trial

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.

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.

Premenstrual disorders: Premenstrual syndrome and premenstrual dysphoric disorder

Recently, the term premenstrual disorders (PMDs), which includes premenstrual syndrome and premenstrual dysphoric disorder as a continuum, has been proposed. Although the precise etiology of PMDs remains unknown, the involvement of hormonal fluctuations is clear. The brain transmitters, serotonin and γ-amino butyric acid, also seem to be involved. Serotonin reuptake inhibitors and oral contraceptives are the current mainstay of treatment, but these are insufficient. Even the currently used prospective two-period symptom diary is not widely used in actual clinical practice, creating a major problem of discrepancy between research and clinical practice. In this review, I would like to outline the latest information and problems in the etiology, diagnosis, and treatment of PMDs, with an emphasis on promising new therapies.

Soy isoflavone-specific biotransformation product S-equol in the colon: physiological functions, transformation mechanisms, and metabolic regulatory pathways

Epidemiological data suggest that regular intake of soy isoflavones may reduce the incidence of estrogen-dependent and aging-associated disorders. Equol is a metabolite of soy isoflavone (SI) produced by specific gut microbiota and has many beneficial effects on human health due to its higher biological activity compared to SI. However, only 1/3 to 1/2 of humans are able to produce equol in the body, which means that not many people can fully benefit from SI. This review summarizes the recent advances in equol research, focusing on the chemical properties, physiological functions, conversion mechanisms in vitro and vivo, and metabolic regulatory pathways affecting S-equol production. Advanced experimental designs and possible techniques in future research plan are also fully discussed. Furthermore, this review provides a fundamental basis for researchers in the field to understand individual differences in S-equol production, the efficiency of metabolic conversion of S-equol, and fermentation production of S-equol in vitro.

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

AIM

Premenstrual syndrome causes disturbances in many women's daily activities. Isoflavones might cause changes in the estrogen cycle by their selective estrogen receptor modulator-like activities. Equol, which is a metabolite of a soy isoflavone, has greater biological activity than other soy isoflavones. In this preliminary study, we aimed to examine the effect of a natural S-equol supplement (SE5-OH) on premenstrual symptoms. The gut microbiota has recently been suggested to play an important role in brain function in psychiatric disease, such as depression. Therefore, we further aimed to evaluate the relationship of the effect of SE5-OH and the gut microbiota at preintervention.

METHODS

Twenty women who showed premenstrual symptoms and were nonequol producers were enrolled in an open-label, single-arm, clinical study in which they received oral SE5-OH for two period cycles. The Daily Record of Severity of Problems (DRSP) total score was evaluated during the intervention cycles. Before taking SE5-OH, fecal samples were obtained and subjected to terminal restriction fragment length polymorphism analysis.

RESULTS

The response rate to treatment (≥50% reduction from baseline in the DRSP total score) was 10.5%. Post hoc analysis showed a significant improvement in the change in the DRSP total score (P = .008) and DRSP scores for four core premenstrual dysphoric disorder symptoms. Multiple regression analysis showed that the percentage improvement of the DRSP total score was positively related to Bifidobacterium and negatively related to Clostridium cluster IV.

CONCLUSION

SE5-OH supplementation may be an acceptable treatment for premenstrual symptoms. The intestinal microbiota may have an effect on SE5-OH.

A Phosphotyrosine Switch in Estrogen Receptor β Is Required for Mouse Ovarian Function

The two homologous estrogen receptors ERα and ERβ exert distinct effects on their cognate tissues. Previous work from our laboratory identified an ERβ-specific phosphotyrosine residue that regulates ERβ transcriptional activity and antitumor function in breast cancer cells. To determine the physiological role of the ERβ phosphotyrosine residue in normal tissue development and function, we investigated a mutant mouse model (Y55F) whereby this particular tyrosine residue in endogenous mouse ERβ is mutated to phenylalanine. While grossly indistinguishable from their wild-type littermates, mutant female mice displayed reduced fertility, decreased ovarian follicular cell proliferation, and lower progesterone levels. Moreover, mutant ERβ from female mice during superovulation is defective in activating promoters of its target genes in ovarian tissues. Thus, our findings provide compelling genetic and molecular evidence for a role of isotype-specific ERβ phosphorylation in mouse ovarian development and function.

Psychometric Testing of the Japanese Version of the Daily Record of Severity of Problems Among Japanese Women

PURPOSE

The Daily Record of Severity of Problems (DRSP) is commonly used to assess premenstrual syndrome and premenstrual dysphoric disorder throughout the world. The aim of this study was to assess the validity and reliability of the Japanese version of the DRSP (DRSP-J).

MATERIALS AND METHODS

We analyzed 324 women with regular menstrual cycles who completed the DRSP-J and the Premenstrual Symptoms Questionnaire (PSQ). They had all applied to participate in an ongoing study for the treatment of their premenstrual symptoms. The DRSP-J was examined for evidence of reliability and validity. To examine reliability, we assessed Cronbach's α, a measure of internal consistency, and test-retest reliability. We assessed structural validity with principal component factor analysis (PCA) and confirmatory factor analysis (CFA). We used PSQ total score to examine concurrent validity.

RESULTS

Cronbach's α for DRSP total score was 0.97. DRSP total score and individual items showed high test-retest reliability. PCA showed a two-factor model describing mood and behavioral and physical symptoms. CFA showed that the two-factor model derived from the PCA was an acceptably good fit. DRSP total score correlated moderately with PSQ total score (r = 0.42).

CONCLUSION

The DRSP-J showed reliable and valid measures of premenstrual symptoms in Japanese women.

Effects of Yeast Mannan Which Promotes Beneficial Bacteroides on the Intestinal Environment and Skin Condition: A Randomized, Double-Blind, Placebo-Controlled Study

Yeast mannan (YM) is an indigestible water-soluble polysaccharide of the yeast cell wall. In vitro fecal fermentation studies showed that YM could exhibit a notable prebiotic effect. The aim of this randomized, double-blind, placebo-controlled study was to assess the efficacy of YM intake on the intestinal environment and skin condition. One hundred and ten healthy female subjects aged 30–49 years were supplemented with YM or placebo for eight weeks. Skin dryness was set as the primary endpoint. No side effects were observed during the study. Microbiota analyses revealed that YM intake selectively increased the relative abundance of Bacteroides thetaiotaomicron and Bacteroides ovatus compared to that by placebo. Feces and urine analyses showed that YM intake lowered the concentration of fecal p-cresol, indole, and skatole, and elevated urinal equol levels compared to those in placebo. Furthermore, YM supplementation ameliorated subjective skin dryness. This study suggests that YM intake could promote beneficial Bacteroides and improve the intestinal environment and skin condition.

Isoflavones and bone health in perimenopausal and postmenopausal women

PURPOSE OF REVIEW

Isoflavones exert estrogenic activity distinct from estrogen, they have the potential to treat diseases and symptoms related to estrogen deficiency with minimal side effects and risks. Isoflavone supplementation, in general, is shown to exert beneficial effects against estrogen-deficient bone loss in women, however, some clinical trials still produce conflicting findings. The purpose of this review is to highlight and summarize the most recent and up-to-date research in the field and to bring attention to factors that play a major role in the outcomes of clinical trials that investigate phytoestrogens. Here, we also discuss the latest and most relevant data regarding the clinical safety of these substances.

RECENT FINDINGS

Isoflavones are naturally occurring secondary metabolites found in the Fabacaea plant family. Clinical data from isoflavone interventions support that aglycones (abundant in fermented products) exert enhanced beneficial effects against estrogen-deficient bone loss in women compared with isoflavone glycosides. Studies that employ methods to determine isoflavone content and form of treatments are more likely detect beneficial effects on bone. EFSA have confirmed the safety of isoflavones for women in the most comprehensive report to date.

SUMMARY

Isoflavone aglycones exert greater effects against bone loss than glycosides. Isoflavones show promise as a first-line prophylactic/treatment for bone loss in women.