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Scope: The aim of this study is to investigate associations between (poly)phenol consumption, circulating (poly)phenol metabolites, and mood states in healthy individuals., Methods and Results: The study included 333 healthy individuals. Mood state was assessed with the Positive and Negative Affect Schedule questionnaire. Dietary (poly)phenol intake was estimated  matching food consumption data collected using a Food Frequency Questionnaire(FFQ) with a comprehensive in-house (poly)phenol database. A total of 102 (poly)phenol metabolites were quantified in fasting plasma and 24 h urine samples by Liquid Chromatography-Mass Spectrometry using a validated method. A higher intake of lignans, flavanones, and flavonols estimated from FFQs was associated with positive mood after adjusting for age and sex (β: 0.118 to 0.134). A total of 11 urinary (poly)phenol metabolites, including lignan and flavonol metabolites were associated with less negative mood (β: -0.387 to -0.205). No association was found between mood and plasma (poly)phenols., Conclusion:   A higher consumption of lignans flavanones and flavonols is associated with a better mood, while certain urinary metabolites are associated with less negative mood. The lack of associations between fasting plasma (poly)phenols and mood may be due to their transient nature incirculation compared with 24 h urinary metabolites, which reflect longer-term exposure., (© 2024 The Author(s). Molecular Nutrition & Food Research published by Wiley‐VCH GmbH.)

Background: The overall understanding of the correlations between mortality risk and phytoestrogens in general population remains limited. We examined the association between urinary phytoestrogen levels and all-cause and cardiovascular mortality based on the National Health and Nutrition Examination Survey (NHANES)., Methods: Weighted Cox proportional hazard regression models were employed to calculate adjusted hazard ratios (HRs) and their 95% confidence intervals (CIs). Nonlinear relationships were assessed using multivariable-adjusted restricted cubic splines (RCS)., Results: In the fully adjusted model, the highest quartiles of urinary genistein levels were correlated with significantly elevated all-cause (HR = 1.36, 95%CI: 1.16-1.59) and cardiovascular (HR = 1.58, 95%CI: 1.20-2.09) mortality. Urinary enterolactone levels in the third quartile were associated with reduced all-cause (HR = 0.77, 95%CI: 0.65-0.90) and cardiovascular (HR = 0.74, 95%CI: 0.55-0.99) mortality. In the highest quartiles of urinary daidzein levels, the cardiovascular mortality was significantly increased (HR = 1.44, 95%CI: 1.09-1.90). RCS showed an non-linear relationship between urinary daidzein levels and all-cause mortality ( P = 0.04)., Conclusion: In the context of a nationally representative sample, genistein exhibited associations with elevated all-cause and cardiovascular mortality, whereas enterolactone showed an association with reduced mortality. The dose-response relationship between urinary daidzein levels and all-cause mortality as well as sex-specific disparities in the impact of phytoestrogen levels should be considered., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Xuan, Zhao, Zhou, Guo, Pan, Wang and He.)

Aims : Plant-derived lignans may protect against obesity, while their bioactivity needs gut microbial conversion to enterolignans. We used repeated measures to identify enterolignan-predicting microbial species and investigate whether enterolignans and enterolignan-predicting microbial species are associated with obesity. Methods : Urinary enterolignans, fecal microbiota, body weight, height, and circumferences of the waist (WC) and hips (HC) were repeatedly measured at the baseline and after 1 year in 305 community-dwelling adults in Huoshan, China. Body composition and liver fat [indicated by the controlled attenuation parameter (CAP)] were measured after 1 year. Multivariate-adjusted linear models and linear mixed-effects models were used to analyze single and repeated measurements, respectively. Results : Enterolactone and enterodiol levels were both inversely associated with the waist-to-hip ratio, body fat mass (BFM), visceral fat level (VFL), and liver fat accumulation (all P < 0.05). Enterolactone levels were also associated with lower WC ( β = -0.0035 and P = 0.013) and HC ( β = -0.0028 and P = 0.044). We identified multiple bacterial genera whose relative abundance was positively associated with the levels of enterolactone (26 genera) and enterodiol (22 genera, all P false discovery rate < 0.05), and constructed the enterolactone-predicting microbial score and enterodiol-predicting microbial score to reflect the overall enterolignan-producing potential of the host gut microbiota. Both these scores were associated with lower body weight and CAP (all P < 0.05). The enterolactone-predicting microbial score was also inversely associated with the BFM ( β = -0.1128 and P = 0.027) and VFL ( β = -0.1265 and P = 0.044). Conclusion : Our findings support that modulating the host gut microbiome could be a potential strategy to prevent obesity by enhancing the production of enterolignans.

The gut microbiome may affect overall cardiometabolic health. Enterolactone is an enterolignan reflective of dietary lignan intake and gut microbiota composition and diversity that can be measured in the urine. The purpose of this study was to examine the association between urinary enterolactone concentration as a reflection of gut health and blood pressure/risk of hypertension in a large representative sample from the US population. This analysis was conducted using data from the National Health and Nutrition Examination Survey (NHANES) collected from January 1999 through December 2010. Variables of interest included participant characteristics (including demographic, anthropometric and social/environmental factors), resting blood pressure and hypertension history, and urinary enterolactone concentration. 10,637 participants (45 years (SE = 0.3), 51.7% (SE = 0.6%) were female) were included in analyses. In multivariable models adjusted for demographic, socioeconomic and behavioral/environmental covariates, each one-unit change in log-transformed increase in enterolactone was associated with a 0.738 point (95% CI: -0.946, -0.529; p<0.001) decrease in systolic blood pressure and a 0.407 point (95% CI: -0.575, -0.239; p<0.001) decrease in diastolic blood pressure. Moreover, in fully adjusted models, each one-unit change in log-transformed enterolactone was associated with 8.2% lower odds of hypertension (OR = 0.918; 95% CI: 0.892, 0.944; p<0.001). Urinary enterolactone, an indicator of gut microbiome health, is inversely associated with blood pressure and hypertension risk in a nationally representative sample of U.S. adults., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Weiner et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Lignans are phytochemicals studied extensively as dietary factors in chronic disease etiology. Our goal was to examine associations between the gut microbiota and lignan metabolism and whether these associations differ by ethnicity. We conducted a flaxseed (FS) dietary intervention in 252 healthy, postmenopausal women of African ancestry (AA) and European ancestry (EA). Participants consumed ~10 g/d ground flaxseed for 6 weeks and provided overnight urine collections and fecal samples before and after intervention. The gut microbiota was characterized using 16S rRNA gene sequencing and differences in microbial community composition compared by ethnicity and intervention status. We observed a significant difference in the composition of the microbiota measured as beta diversity ( p < 0.05) between AA and EA at baseline that was attenuated with FS consumption. Genera that were significantly associated with ENL production (e.g., Klebsiella , Lactobacillus , Slackia , Senegalimassilia ) were unique to each group. Bacteria (e.g., Fusobacteria , Pyramidobacter and Odoribacter ) previously associated with colorectal cancer and cardiovascular disease, both diet-related chronic diseases, were unique to either AA or EA and were significantly reduced in the FS intervention. This study suggests that ethnic variation in ENL metabolism may be linked to gut microbiota composition, and its impact on disease risk deserves future investigation.

Mammalian lignans are phytoestrogens with important bioactivities, and their concentrations in livestock milk may influence the health of consumers. This research aimed to establish a method to quantify multiple mammalian lignans in the biofluids of dairy sheep using ultra-HPLC-triple quadropole mass spectrometry with multiple-reaction monitoring. Secoisolariciresinol, 2-[(4-hydroxy-3-methoxyphenyl)methyl]-3-[(3-hydroxyphenyl)methyl]-1,4-butanediol, enterodiol (ED), enterolactone (EL), ED-sulfate (ED-S), and EL-sulfate (EL-S) were purified from the urine of flaxseed cake-fed dairy sheep. The structures of these lignans were identified by a combination of mass and nuclear magnetic resonance spectra. These purified lignans were used as standards to optimize their quantification conditions in urine, milk, and plasma of dairy sheep. On this basis, the lignan metabolites in biofluids were quantified. To improve analysis sensitivity, plasma and milk were pretreated with acetonitrile containing 1% formic acid and passed through a HybridSPE-PL 55261-U column (Supelco, Bellefonte, PA). The limit of quantification of the lignans ranged from 1.43 to 18.3 ng/mL in plasma, and from 1.01 to 18.7 ng/mL in milk. The linearity of the calibration curves ranged from their limit of quantification to at least 217 ng/mL in plasma, and 217 ng/mL in milk. Regression coefficient of the calibration curves were above 0.99 for secoisolariciresinol, 2-[(4-hydroxy-3-methoxyphenyl)methyl]-3-[(3-hydroxyphenyl)methyl]-1,4-butanediol, ED, EL, ED-S, and EL-S, indicating satisfactory relationships between the peak areas and concentrations in the quantification range. The relative concentrations of ED-glucuronide and EL-glucuronide (EL-G) in different biofluids were compared based on their chromatogram peak areas. The sheep plasma contained all forms of mammalian lignans (i.e., ED, EL, ED-S, EL-S, ED-glucuronide, and EL-G.); the urine contained ED, EL, ED-S, and EL-S; and the milk contained ED, EL, ED-S, EL-S, and EL-G. Milk-to-plasma concentration ratios of the mammalian lignans indicated that the free forms were more permeable than the sulfated conjugates. Mammalian lignans found in sheep plasma and milk may provide health benefits to the sheep and sheep-product consumers. The analytical method established in this work could be used to quantify mammalian lignans in livestock products., (Copyright © 2021 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)

Current evidence on the relationship of phytoestrogens with sleep is limited and contradictory. In particular, studies on individual phytoestrogens and sleep have not been reported. Thus, this study aimed to appraise the associations of individual phytoestrogens with sleep disorders and sleep duration. This cross-sectional study comprising 4830 adults utilized data from the National Health and Nutrition Examination Survey 2005-2010. Phytoestrogens were tested in urine specimens. Sleep disorders and sleep duration were based on a self-reported doctor's diagnosis and usual sleep duration. The main analyses utilized logistic and multinomial logistic regression models and a restricted cubic spline. In the fully adjusted model, compared with tertile 1 (lowest), the odds ratios (95% confidence intervals (CIs)) of sleep disorders for the highest tertile of urinary concentrations of enterolactone, enterodiol, and O-desmethylangolensin were 0.64 (0.41-1.00), 1.54 (1.07-2.21), and 1.89 (1.26-2.85), respectively. Linear inverse, approximatively linear positive, and inverted L-shaped concentration-response relationships were found between enterolactone, enterodiol, and O-desmethylangolensin and sleep disorders, respectively. Compared with normal sleep (7-8 h/night), the relative risk ratio (RRR) (95% CI) of very short sleep for enterolactone was 0.56 (0.36-0.86), and the RRR (95% CI) of long sleep risk for genistein was 0.62 (0.39-0.99). Furthermore, negative associations of genistein with sleep disorders and enterolactone with long sleep risk, as well as positive associations of enterodiol with both long and very short sleep, were observed in the stratified analysis by age or gender. Finally, a notable finding was that urinary O-desmethylangolensin concentration was positively related to sleep disorders in both females aged 40-59 years and non-Hispanic Whites but inversely associated with sleep disorders in both females aged 60 years or over and other Hispanics. Our findings suggested that enterolactone and genistein might be beneficial for preventing sleep disorders or non-normal sleep duration among adults, and enterodiol might be adverse toward this goal. However, the association of O-desmethylangolensin with sleep disorders might be discrepant in different races and females of different ages.

Background: Enterolignans are important biomarkers of microbiota diversity, with higher levels indicating greater diversity. Diet and inflammation have been shown to play a role in maintaining microbiota diversity. This study examined whether inflammatory potential of diet, as measured by the Dietary Inflammatory Index (DII ® ) has an impact on levels of urinary enterolignans in the National Health and Nutrition Examination Survey (NHANES) 2003-2008. We also carried out construct validation of the DII with C-reactive protein (CRP)., Methods: Data came from NHANES 2003-2008. Enterolignans [enterodiol (END) and enterolactone (ENL)] and CRP were assayed from urine and serum specimens, respectively. Energy-adjusted DII (E-DII) scores were calculated from food intakes assessed using 24-h dietary recalls and expressed per 1000 calories consumed. Associations were examined using survey-based multivariable linear and logistic regression for enterolignans, and logistic regression for CRP., Results: After multivariable adjustment, higher E-DII scores (i.e., indicating a relatively more pro-inflammatory diet) were associated with lower levels of creatinine-normalized END [beta coefficient (b) DIIquartile4vs1  = - 1.22; 95% CI = - 0.69, - 1.74; P trend  ≤ 0.001] and ENL (b DIIquartile4vs1  = - 7.80; 95% CI = - 5.33, - 10.26; P trend  ≤ 0.001). A positive association was also observed when enterolignans were dichotomized based on the cut-off of the 75th percentile value. In this same sample, the E-DII also was associated with CRP ≥ 3 mg/l (OR DIIcontinuous  = 1.12; 95% CI 1.05, 1.19)., Conclusion: In these NHANES data, there was an association between E-DII score and enterolignans. This study also provided construct validation of the E-DII using CRP in a nationally representative sample. The results indicate that dietary inflammatory potential is associated with urinary enterolignans, a potential marker for microbiota diversity. However, studies are required to understand the direct association between DII and microbiota.

Background: Metabolism and excretion of the phytoestrogen enterolactone (ENL), which has been associated with breast cancer risk, may be affected by variation in steroid hormone and xenobiotic-metabolizing genes., Methods: We conducted a randomized, crossover flaxseed intervention study in 252 healthy, postmenopausal women [137 European ancestry (EA) and 115 African ancestry (AA)] from western New York. Participants were randomly assigned to maintain usual diet or consume 10 g/day ground flaxseed for 6 weeks. After a 2-month washout period, participants crossed over to the other diet condition for an additional 6 weeks. Urinary ENL excretion was measured by gas chromatography-mass spectrometry and 70 polymorphisms in 29 genes related to steroid hormone and xenobiotic metabolism were genotyped. Mixed additive genetic models were constructed to examine association of genetic variation with urinary ENL excretion at baseline and after the flaxseed intervention., Results: SNPs in several genes were nominally ( P < 0.05) associated with ENL excretion at baseline and/or after intervention: ESR1, CYP1B1, COMT, CYP3A5, ARPC1A, BCL2L11, SHBG, SLCO1B1 , and ZKSCAN5 . A greater number of SNPs were associated among AA women than among EA women, and no SNPs were associated in both races. No SNP-ENL associations were statistically significant after correction for multiple comparisons., Conclusions: Variation in several genes related to steroid hormone metabolism was associated with lignan excretion at baseline and/or after flaxseed intervention among postmenopausal women., Impact: These findings may contribute to our understanding of the differences observed in urinary ENL excretion among AA and EA women and thus hormone-related breast cancer risk., (©2019 American Association for Cancer Research.)

Enterolignans, products of gut bacterial metabolism of plant lignans, have been associated with reduced risk of chronic diseases, but their association with other plasma metabolites is unknown. We examined plasma metabolite profiles according to urinary enterolignan excretion in a cross-sectional analysis using data from a randomized crossover, controlled feeding study. Eighty healthy adult males and females completed two 28-day feeding periods differing by glycemic load, refined carbohydrate, and fiber content. Lignan intake was calculated from food records using a polyphenol database. Targeted metabolomics was performed by LC-MS on plasma from fasting blood samples collected at the end of each feeding period. Enterolactone (ENL) and enterodiol, were measured in 24 h urine samples collected on the penultimate day of each study period using GC-MS. Linear mixed models were used to test the association between enterolignan excretion and metabolite abundances. Pathway analyses were conducted using the Global Test. Benjamini-Hochberg false discovery rate (FDR) was used to control for multiple testing. Of the metabolites assayed, 121 were detected in all samples. ENL excretion was associated positively with plasma hippuric acid and melatonin, and inversely with epinephrine, creatine, glycochenodeoxycholate, and glyceraldehyde (P < 0.05). Hippuric acid only satisfied the FDR of q < 0.1. END excretion was associated with myristic acid and glycine (q < 0.5). Two of 57 pathways tested were associated significantly with ENL, ubiquinone and terpenoid-quinone biosynthesis, and inositol phosphate metabolism. These results suggest a potential role for ENL or ENL-metabolizing gut bacteria in regulating plasma metabolites.

Antibiotics excreted into the intestinal tract may disrupt the microbiota that provide colonization resistance against enteric pathogens and alter normal metabolic functions of the microbiota. Many of the bacterial metabolites produced in the intestinal tract are absorbed systemically and excreted in urine. Here, we used a mouse model to test the hypothesis that alterations in levels of targeted bacterial metabolites in urine specimens could provide useful biomarkers indicating disrupted or intact colonization resistance. To assess in vivo colonization resistance, mice were challenged with Clostridium difficile spores orally 3, 6, and 11 days after the completion of 2 days of treatment with piperacillin-tazobactam, aztreonam, or saline. For concurrent groups of antibiotic-treated mice, urine samples were analyzed by using liquid chromatography-tandem mass spectrometry (LC-MS/MS) to quantify the concentrations of 11 compounds targeted as potential biomarkers of colonization resistance. Aztreonam did not affect colonization resistance, whereas piperacillin-tazobactam disrupted colonization resistance 3 days after piperacillin-tazobactam treatment, with complete recovery by 11 days after treatment. Three of the 11 compounds exhibited a statistically significant and >10-fold increase (the tryptophan metabolite N -acetyltryptophan) or decrease (the plant polyphenyl derivatives cinnamoylglycine and enterodiol) in concentrations in urine 3 days after piperacillin-tazobactam treatment, followed by recovery to baseline that coincided with the restoration of in vivo colonization resistance. These urinary metabolites could provide useful and easily accessible biomarkers indicating intact or disrupted colonization resistance during and after antibiotic treatment., (Copyright © 2017 American Society for Microbiology.)

The aim of this study was to examine the relationship between dietary contribution of ultra-processed foods and urinary phytoestrogen concentrations in the US. Participants from cross-sectional 2009-2010 National Health and Nutrition Examination Survey aged 6+ years, selected to measure urinary phytoestrogens and with one 24-h dietary recall were evaluated (2692 participants). Food items were classified according to NOVA (a name, not an acronym), a four-group food classification based on the extent and purpose of industrial food processing. Ultra-processed foods are formulations manufactured using several ingredients and a series of processes (hence "ultra-processed"). Most of their ingredients are lower-cost industrial sources of dietary energy and nutrients, with additives used for the purpose of imitating sensorial qualities of minimally processed foods or of culinary preparations of these foods. Studied phytoestrogens included lignans (enterolactone and enterodiol) and isoflavones (genistein, daidzein, O -desmethylangolensin and equol). Gaussian regression was used to compare average urinary phytoestrogen concentrations (normalized by creatinine) across quintiles of energy share of ultra-processed foods. Models incorporated survey sample weights and were adjusted for age, sex, race/ethnicity, family income, and education, among other factors. Adjusted enterodiol geometric means decreased monotonically from 60.6 in the lowest quintile to 35.1 µg/g creatinine in the highest, while adjusted enterolactone geometric means dropped from 281.1 to 200.1 across the same quintiles, respectively. No significant linear trend was observed in the association between these quintiles and isoflavone concentrations. This finding reinforces the existing evidence regarding the negative impact of ultra-processed food consumption on the overall quality of the diet and expands it to include non-nutrients such as lignans.

Objective: This study examined the cross-sectional association between phytoestrogens and speed of processing. We hypothesized that higher levels of phytoestrogens would be related to better cognitive performance among older women., Methods: Participants were from the National Health and Nutrition Examination Survey and consisted of 200 older women (M = 74.4 y). Stepwise regressions examined indicators of speed of processing, measured by the Digit Symbol Substitution Test. Isoflavones, lignans, and individual phytoestrogens were added to the regression after including covariates of age, education, race, smoking, and creatinine. Isoflavones were further broken into quartiles among the sample to further evaluate the nature of the curvilinear association., Results: Results showed a relationship between cognition and lignans, explaining 3.8% of the variance after including the covariates, indicating fewer lignans were associated with better speed of processing (P < 0.001). A significant curvilinear relationship with isoflavones explained 1.3% additional variance (P < 0.001). The moderate-high, low-moderate, and the lowest quartile of isoflavones were associated with better cognition, whereas the highest amount was associated with worse speed of processing. Among the individual phytoestrogens, only enterodiol accounted for 4.4% additional variance after taking into account covariates and indicated a negative association with cognition (P = 0.03)., Conclusions: Results suggest that moderate levels of isoflavones, but not lignans, may be associated with better speed of processing. Caution must remain for high isoflavone amounts due to the negative association with cognition. Given the results, phytoestrogens have the potential to be an intervention target for older females' cognition. To become a viable intervention, further research is needed.

Background: Equol is a metabolite of daidzein that is produced by intestinal microbiota. The oestrogenic activity of equol is stronger than daidzein. Equol-producing bacteria are believed to play an important role in the gut. The rod-shaped and Gram-positive anaerobic equol-producing intestinal bacterium Slackia TM-30 was isolated from healthy human faeces and its effects on urinary phyto-oestrogen, plasma and faecal lipids were assessed in adult mice., Results: The urinary amounts of equol in urine were significantly higher in mice receiving the equol-producing bacterium TM-30 (BAC) group than in the control (CO) group (P < 0.05). However, no significant differences were observed between the urinary amounts of daidzein, dihydrodaidzein, enterodiol, and enterolactone between the BAC and CO groups. No significant differences in the plasma lipids were observed between the two groups. The lipid content (% dry weight) in the faeces sampled on the final day of the experiment tended to be higher in the BAC group than in the CO group (P = 0.07)., Conclusion: Administration of equol-producing bacterium TM-30 affected the urinary amounts of phyto-oestrogens and the faecal lipid contents of mice. The equol-producing bacterium TM-30 likely influences the metabolism of phyto-oestrogen via changes in the gastrointestinal environment. © 2015 Society of Chemical Industry., (© 2015 Society of Chemical Industry.)

Scope: This study aimed to improve the knowledge of secoisolariciresinol diglucoside (SDG) transformation by human gut microbiota., Methods and Results: SDG-supplemented microbiota cultures were inoculated with the feces of five subjects. The same volunteers received a flaxseed supplement for 7 days. SDG metabolites in cultures, feces, and urine were monitored by LC-ESI-QTOF and LC-DAD. In all cultures, SDG was deglycosylated to secoisolariciresinol (SECO) within 12 h. SECO underwent successive dehydroxylations and demethylations yielding enterodiol (4-18% conversion) and enterolactone (0.2-6%) after 24 h. Novel intermediates related to SECO, matairesinol (MATA), and anhydrosecoisolariciresinol (AHS) were identified in fecal cultures. These metabolites were also found after flaxseed consumption in feces and urine (in approximate amounts between 0.01-47.03 μg/g and 0.01-13.49 μg/mL, respectively) in their native form and/or modified by phase II human enzymes (glucuronide, sulfate and sulfoglucuronide conjugates)., Conclusions: Derivatives of MATA and AHS are described for the first time as intermediates of SDG biotransformation by intestinal bacteria, providing a more comprehensive knowledge of lignan intestinal metabolism. The transformations observed in vitro seem to occur in vivo as well. The detection in urine of SDG intermediates indicates their gut absorption, opening new perspectives on the study of their systemic biological effects., (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Plant lignans are diphenolic compounds ingested with whole grains and seeds and converted to enterolignans by the colonic microbiota. In the present study, we investigated absorption and metabolism of plant lignans and enterolignans in vivo after consumption of cereal-based diets. Six pigs fitted with catheters in the mesenteric artery and portal vein and with a flow probe attached to the portal vein along with twenty pigs for quantitative collection of urine were used for this study. The animals were fed bread based on wheat flour low in plant lignans and three lignan-rich breads based on whole-wheat grain, wheat aleurone flour or rye aleurone flour. Plant lignans and enterolignans in plasma were monitored daily at fast after 0-3 d of lignan-rich intake, and on the 4th day of lignan-rich intake a 10-h profile was completed. Urine samples were collected after 11 d of lignan-rich diet consumption. The concentrations of plant lignans were low at fast, and was 1·2-2·6 nmol/l after switching from the low-lignan diet to the lignan-rich diets. However, on the profile day, the concentration and quantitative absorption of plant lignans increased significantly from 33 nmol/h at fast to 310 nmol/h 0-2·5 h after ingestion with a gradual increase in the following periods. Quantitatively, the absorption of plant lignans across diets amounted to 7 % of ingested plant lignans, whereas the urinary excretion of plant lignans was 3 % across diets. In conclusion, there is a substantial postprandial uptake of plant lignans from cereals, suggesting that plant lignans are absorbed from the small intestine.

We evaluated the relationship between urine concentrations of phyto-oestrogens (isoflavones and lignans) and risk of incident type 2 diabetes in middle-aged and elderly Chinese residing in Singapore. Urine metabolites of isoflavones and lignans were assayed by HPLC among 564 diabetes cases and 564 matched controls in a case-control study nested within the Singapore Chinese Health Study cohort. Participants were free of diagnosed diabetes, CVD and cancer at morning urine collections during 1999-2004. Cases were participants who reported to have physician-diagnosed diabetes at follow-up visits during 2006-2010, whereas controls were randomly selected among those who remained free of diabetes and were matched to the index cases by age, sex, dialect group and date of urine collection. Conditional logistic regression models were used to calculate OR and 95 % CI with adjustment for potential confounders. The mean age of the participants at the time of urine collection was 59·8 years, and the average interval between urine collection and diabetes diagnosis was 4·0 years. The multivariate-adjusted OR for diabetes were 1·00 (reference), 0·76 (95 % CI 0·52, 1·11), 0·78 (95 % CI 0·53, 1·14) and 0·79 (95 % CI 0·54, 1·15) across quartiles of urine isoflavones (P for trend=0·54), and were 1·00 (reference), 0·87 (95 % CI 0·60, 1·27), 1·10 (95 % CI 0·77, 1·56) and 0·93 (95 % CI 0·63, 1·37) for lignans (P for trend=0·93). The results were similar in men and women, as well as for individual metabolites of isoflavones (genistein, daidzein, glycitin and equol) or lignans (enterodiol and enterolactone). The present study did not find a significant association between urine phyto-oestrogen metabolites and risk of type 2 diabetes in Chinese adults.

Purpose: Experimental studies suggest that phytoestrogen intake alters cancer and cardiovascular risk. This study investigated the associations of urinary phytoestrogens with total cancer (n = 79), cardiovascular (n = 108), and all-cause (n = 290) mortality among 5179 participants in the continuous National Health and Nutrition Examination Survey (1999-2004)., Methods: Urinary phytoestrogens were measured using high-performance liquid chromatography with tandem mass spectrometric detection. Survival analysis was performed to evaluate hazard ratios (HRs) and 95 % confidence intervals (CIs) for each of the three outcomes in relation to urinary phytoestrogens., Results: After adjustment for confounders, higher urinary concentrations of total enterolignans were associated with a reduced risk of death from cardiovascular disease (HR for tertile 3 vs. tertile 1 0.48; 95 % CI 0.24, 0.97), whereas higher urinary concentrations of total isoflavones (HR for tertile 3 vs. tertile 1 2.14; 95 % CI 1.03, 4.47) and daidzein (HR for tertile 3 vs. tertile 1 2.05; 95 % CI 1.02, 4.11) were associated with an increased risk. A reduction in all-cause mortality was observed for elevated urinary concentrations of total enterolignans (HR for tertile 3 vs. tertile 1 0.65; 95 % CI 0.43, 0.96) and enterolactone (HR for tertile 3 vs. tertile 1 0.65; 95 % CI 0.44, 0.97)., Conclusions: Some urinary phytoestrogens were associated with cardiovascular and all-cause mortality in a representative sample of the US population. This is one of the first studies that used urinary phytoestrogens as biomarkers of their dietary intake to evaluate the effect of these bioactive compounds on the risk of death from cancer and cardiovascular disease.

Background: Exposure to artificial or natural endocrine disruptors, such as bisphenol A (BPA) and phytoestrogens has been demonstrated to have health effects, especially in children. Biomonitoring of BPA and phytoestrogens in human urine can be used to assess the intake levels of these compounds., Methods: In this study, BPA and phytoestrogens in urine specimens (n = 256) collected from children in China were measured by liquid chromatography (LC)-tandem mass spectrometry (MS/MS)., Results: BPA was detected in most specimens, with a geometric mean concentration of 1.58 ng/mL. For the first time, levels of urinary phytoestrogens in Chinese children were reported. Daidzein and enterolactone are the typical isoflavones and lignans compounds in urine, respectively., Conclusions: Relatively high levels of urinary BPA indicate an increasing risk of BPA exposure to Chinese children. Urinary concentrations of daidzein in Chinese children are higher when compared with those reported in the U.S. children, while concentrations of urinary enterolactone and enterodiols are significantly lower. This suggests a significant difference in phytoestrogen intake between the children from China and from the U.S.

Background: Phytoestrogens have been associated with subtle hormonal changes, although effects on male fecundity are largely unknown., Objective: We evaluated associations between male urinary phytoestrogen (isoflavone and lignan) concentrations and semen quality., Methods: This study was a prospective cohort study of 501 male partners of couples desiring pregnancy and discontinuing contraception. Each participant provided up to 2 semen samples that were analyzed for 35 semen quality endpoints the following day. Linear mixed-effects models were used to estimate associations between baseline urinary phytoestrogen concentrations and semen quality parameters, adjusted for age, body mass index (BMI), research site, and serum lipid and cotinine concentrations., Results: Most associations between urinary phytoestrogens and semen quality parameters were null. However, select individual phytoestrogens were associated with semen quality parameters, with associations dependent on the class of phytoestrogens and modified by BMI. Specifically, genistein and daidzein were associated with a lower percentage of normal sperm and increased abnormalities in semen morphology, with reduced associations observed as BMI increased (P < 0.05) [percentages (95% CIs) of normal morphology by WHO traditional criteria: genistein, main effect: -5.61% (-9.42%, -1.79%); interaction: 0.19% (0.06%, 0.31%) per log unit increase; daidzein, main effect: -5.35% (-9.36%, -1.34%); interaction: 0.18% (0.05%, 0.32%) per log unit increase]. Enterolactone was associated with fewer abnormalities in semen morphometry and morphology and decreased DNA fragmentation, with reduced associations observed as BMI increased (P < 0.05) [percentages (95% CIs) of abnormalities in the neck and midpiece: enterolactone, main effect: -3.35% (-6.51%, -0.19%); interaction: 0.11% (0.01%, 0.21%) per log unit increase]., Conclusions: These results suggest that male urinary phytoestrogen concentrations characteristic of the US population may be associated with subtle indicators of male fecundity and semen quality but were not associated with couple fecundity., (© 2015 American Society for Nutrition.)

During pregnancy, human exposure to endogenous estrogens and xenoestrogens (such as lignans) may comprehensively impact the gestational maintenance and fetal growth. We measured the concentrations of 5 lignans and the profile of 13 estrogen metabolites (EMs) in the urine samples of 328 pregnant women and examined their associations with birth outcomes. We found significantly positive associations between gestational age and urinary matairesinol (MAT), enterodiol (END) and enterolactone (ENL), as well as 16-hydroxylation pathway EMs. There were consistently positive relationships between END and the 16-hydroxylation pathway EMs. The positive relationships of MAT, END and ENL exposures with the length of gestation were mainly in the low exposure strata of the levels of these EMs. This study reveals that MAT, END and ENL as well as 16-hydroxylation pathway EMs are associated with birth outcomes, and that there are interactive relationships between lignans and 16-hydroxylation pathway EMs with birth outcomes., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Objective: To examine the association between urinary phytoestrogens and self-reported urinary incontinence in postmenopausal women in the United States using a large, cross-sectional, population-based cohort survey., Methods: Data were analyzed for 1789 postmenopausal women aged 50 years or older who participated in one of the 2001-2010 cycles of National Health and Nutrition Examination Survey and underwent measurement of 4 isoflavone (soy derived) and 2 lignan (flax derived) phytoestrogens in their urine. Incontinence was defined as self-reported stress, urge, other, or mixed incontinence. Urine phytoestrogen concentrations were examined in weighted, multivariate logistic regression models for association with each of the lower urinary tract symptoms. All models were adjusted for age, body mass index, diabetes, race, smoking, and parity., Results: Increasing urine concentrations of the lignan phytoestrogen enterodiol was associated with decreased likelihood of urge (odds ratio [OR], 0.92; 95% confidence interval [CI], 0.85-0.99), mixed (OR, 0.90; 95% CI, 0.82-0.98), and other (OR, 0.90; 95% CI, 0.81-0.99) incontinence, whereas increasing urine concentrations of the lignan phytoestrogen enterolactone was associated with decreased likelihood of urge (OR, 0.92; 95% CI, 0.86-0.99) and mixed (OR, 0.91; 95% CI, 0.84-0.99) incontinence. No association was observed between any isoflavone phytoestrogens and types of incontinence., Conclusion: This study demonstrates that lignan phytoestrogens may have a protective effect against incontinence in postmenopausal women. Prospective clinical and laboratory studies are warranted to investigate the mechanism of this relationship., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Results from animal studies have consistently suggested that lignans play a role in the regulation of in body weight, but evidence from human studies has been limited. We examined the associations between urinary excretion of enterolactone and enterodiol, the major intestinal microbial metabolites of dietary lignans, and 10-year prospective weight change using data from 2 well-characterized cohort studies of US women: the Nurses' Health Study (2000-2010) and Nurses' Health Study II (1997-2007). Urinary excretion levels of enterolactone and enterodiol were measured at baseline. Associations with prospective weight change were analyzed using a multivariable-adjusted linear mixed-effects model. We observed that women in the highest quartile of urinary excretion of total lignans had significantly lower baseline body mass indices (weight in kilograms divided by height in meters squared) (mean, 24.6, 95% confidence interval (CI): 23.9, 25.2) than did those in the lowest quartile (mean, 27.7, 95% CI: 27.0, 28.4; P for trend < 0.01). Compared with women in the lowest quartile of enterodiol excretion, those in the highest quartile gained 0.27 kg/year less weight (95% CI: 0.12, 0.41; P for trend < 0.01) during the 10-year follow-up. The association was borderline significant for enterolactone (for the fourth vs. first quartile, least square mean of weight change rate = -0.14 kg/year, 95% CI: -0.29, 0.00). Our data suggest that higher urinary excretion of lignan metabolites, especially enterodiol, is associated with modestly slower weight gain., (© The Author 2015. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Lignans have gained nutritional interest due to their promising role in the prevention of lifestyle diseases. However, epidemiological studies are in need of more evidence to link the intake of lignans to this promising role. In this context, it is necessary to study large population groups to obtain sufficient statistical power. Therefore, there is a demand for fast, sensitive, and accurate methods for quantitation with high throughput of samples. This paper presents a validated LC-MS/MS method for the quantitation of eight plant lignans (matairesinol, hydroxymatairesinol, secoisolariciresinol, lariciresinol, isolariciresinol, syringaresinol, medioresinol, and pinoresinol) and two enterolignans (enterodiol and enterolactone) in both human and pig plasma and urine. The method showed high selectivity and sensitivity allowing quantitation of lignans in the range of 0.024-100 ng/mL and with a run time of only 4.8 min per sample. The method was successfully applied to quantitate lignans in biofluids from ongoing studies with humans and pigs.

Phyto-oestrogens are a family of plant-derived xeno-oestrogens that appear to have beneficial effects on human health. To date, no data are available about phyto-oestrogen consumption affecting liver health in a population. The present study aimed to explore the relationship of urinary phyto-oestrogen metabolites with serum liver enzymes in US adults. A nationally representative sample of US adults in the National Health and Nutrition Examination Survey (NHANES) 2003-10 was analysed. The cross-sectional study sample consisted of 6438 adults with data on urinary phyto-oestrogen levels, serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and γ-glutamyl transaminase (GGT) concentrations and data on other potential confounders. Multivariate logistic regression and linear regression were applied to assess associations between urinary phyto-oestrogen levels and ALT, AST, ALP and GGT concentrations. We found a remarkable association between urinary enterolactone and GGT in both adult males (OR 0.37, 95 % CI 0.22, 0.61; P= 0.003) and females (OR 0.37, 95 % CI 0.26, 0.54; P= 0.009). Moreover, elevated enterolactone levels were inversely associated with ALT and AST levels in adult males. However, no association was present between levels of urinary daidzein, O-desmethylangolensin, equol, enterodiol or genistein with liver enzyme levels in this population. The present study results provide epidemiological evidence that urinary enterolactone levels are associated with liver GGT levels in humans. This suggests a potential protective effect of enterolactone on human liver function. However, the underlying mechanisms still need further investigation.

Phyto-oestrogens are a family of plant-derived xeno-oestrogens that have been shown to prevent cancer in some studies. Whether phyto-oestrogen intake affects obesity status in a population is still unclear. In the present cross-sectional study, we examined the association of urinary phyto-oestrogen metabolites with obesity and metabolic parameters in children and adults. Data from 1294 children (age 6-19 years) and from 3661 adults (age ≥ 20 years) who participated in the US National Health and Nutrition Examination Survey 2001-10 were analysed. Multivariate logistic regression was applied to investigate the associations of BMI, waist circumference, serum metabolites (total cholesterol, HDL-cholesterol, LDL-cholesterol, TAG, fasting glucose and fasting insulin) and the metabolic syndrome with urinary phyto-oestrogen levels. When stratified by age and sex, we found a stronger association (OR 0·30, 95 % CI 0·17, 0·54; P< 0·001) between urinary enterolactone levels and obesity in adult males (age 20-60 years) than in children (age 12-19 years) or the elderly (age >60 years) in the same survey. However, no associations with urinary daidzein, O-desmethylangolensin, equol, enterodiol or genistein were found in the overall population. We also found that the elevation of enterolactone levels was inversely associated with TAG levels, fasting glucose levels, fasting insulin levels and the metabolic syndrome in males aged 20-60 years, but positively associated with HDL-cholesterol levels. The present results provide epidemiological evidence that urinary enterolactone is inversely associated with obesity in adult males.

The fruit of Schisandra chinensis is a well-known herbal medicine and dietary supplement due to a variety of biological activities including antihepatotoxic and antihyperlipidemic activities. However, the simultaneous validation methodology and pharmacokinetic investigation of nine lignans of S. chinensis extract in biological samples have not been proved yet. Thus, the present study was undertaken to develop the proper sample preparation method and simultaneous analytical method of schisandrol A, gomisin J, schisandrol B, tigloylgomisin H, angeloylgomisin H, schisandrin A, schisandrin B, gomisin N, and schisandrin C in the hexane-soluble extract of S. chinensis to apply for the pharmacokinetic study in rats. All intra- and interprecisions of nine lignans were below 13.7% and accuracies were 85.1-115% and it is enough to evaluate the pharmacokinetic parameters after both intravenous and oral administration of hexane-soluble extract of S. chinensis to rats., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The study objective was to evaluate independent and interactive associations of dietary fiber intake and high urinary enterolignans with cardiometabolic risk factors. The analysis included 2260 adults (≥20 y of age) from the 2003-2010 NHANES. Logistic regression models were used to evaluate obesity and clinically defined cardiometabolic risk factors in relation to dietary fiber intake and urinary enterolignan concentrations. Three sets of models were created: 1) independent associations, 2) mutually adjusted associations, and 3) interactions. Models were adjusted for age, gender, race/ethnicity, education, smoking status, and energy intake. High concentrations were considered to be above the 90th percentile of urinary enterolignan concentrations. Increasing dietary fiber intake was associated with high blood pressure (P = 0.02) and low serum HDL cholesterol (P-trend = 0.03). High urinary enterodiol concentration was not associated with obesity or cardiometabolic risk factors. High urinary enterolactone concentration was inversely associated with obesity (OR: 0.44; 95% CI: 0.29, 0.66), abdominal obesity (OR: 0.58; 95% CI: 0.39, 0.87), high serum C-reactive protein (CRP; OR: 0.52; 95% CI: 0.37, 0.74), high serum triglycerides (OR: 0.39; 95% CI: 0.23, 0.61), low serum HDL cholesterol (OR: 0.37; 95% CI: 0.23, 0.61), and metabolic syndrome (OR: 0.47; 95% CI: 0.30, 0.74). In mutually adjusted models, enterolactone associations observed in independent models remained similar, but associations for dietary fiber intake were attenuated, with the exception of blood pressure. In interaction models, there were 2 significant interactions: between high urinary enterodiol concentration and dietary fiber intake for high serum CRP (P = 0.04) and high plasma glucose (P = 0.04). Overall, being in the highest 10% of urinary enterolactone concentration was associated with cardiometabolic risk factors, independent of dietary fiber intake and enterodiol concentration. Future studies are warranted to evaluate physiologic actions of enterolactone or aspects of the gut microbial profile responsible for lignan metabolism to enterolactone., (© 2014 American Society for Nutrition.)

This study aims at investigating the effect of an experimental period of intake of whole grain foods rich in lignans as part of an habitual diet on the plasma and urinary excretion of enterolignans, the biomarkers of lipid metabolism and the immunological and antioxidant status in a group of postmenopausal women with moderate serum cholesterol. A randomized double-blind crossover study was completed on 13 subjects in 12-weeks after protocol approval of an ethical committee. The subjects consumed whole grain foods high in lignans (30 g/d of breakfast cereals or biscuits, etc., 80 g/d of whole grain pasta) or refined grain foods for 4 weeks, separated by a 2-weeks wash-out period. A modest hypocholesterolemic effect (p < 0.05) of the whole grain diet was observed and the intake of whole grain products rich in lignans was also associated with an increase in urinary enterodiol excretion (p < 0.05).

Phytoestrogens are plant-derived compounds that may interact with estrogen receptors and mimic estrogenic effects. It remains unclear whether the individual variability in metabolizing phytoestrogens contributes to phytoestrogens-induced beneficial or detrimental effects. Our aim was to determine whether there is any interaction between metabolic rates (MR) of phytoestrogens and genetic polymorphisms in related xenobiotic metabolizing enzyme genes. MR was used to assess phytoestrogen exposure and individual metabolic ability. The amount of phytoestrogens in urine was measured by ultra-high performance liquid chromatography-tandem mass spectrometry in 600 idiopathic infertile male patients and 401 controls. Polymorphisms were genotyped using the SNPstream platform combined with the Taqman method. Prototypes and metabolites of secoisolariciresinol (SEC) have inverse effects on male reproduction. It was found that low MR of SEC increased the risk of male infertility (OR 2.49, 95 % CI 1.78, 3.48, P trend = 8.00 × 10(-8)). Novel interactions were also observed between the MR of SEC and rs1042389 in CYP2B6, rs1048943 in CYP1A1, and rs1799931 in NAT2 on male infertility (P inter = 1.06 × 10(-4), 1.14 × 10(-3), 3.55 × 10(-3), respectively). By analyzing the relationships between urinary phytoestrogen concentrations, their metabolites and male infertility, we found that individual variability in metabolizing SEC contributed to the interpersonal differences in SEC's effects on male reproduction.

A prospective and double-blind study was conducted on 35 women with weight excess who consumed 25 grams of quinoa flakes (QF) or corn flakes (CF) daily during a period of four consecutive weeks. At the beginning (T1) and at the end (T2) of the intervention, total calorie intake was evaluated, anthropometric assessment was performed, blood was collected for the determination of glucose, total cholesterol and fractions, oxidative stress markers, vitamin E and enterolignans. Significant reductions were detected in serum triglyceride (CF group = 133.9 ± 89.4 to 113.7 ± 57 mg/dl and QF group = 112.3 ± 35 to 107.9 ± 33.1 mg/dl), TBARS (CF group = 3.2 ± 0.8 to 2.9 ± 0.5 µmol/l and QF group = 3.06 ± 0.6 to 2.89 ± 0.5 µmol/l) and vitamin E concentrations (CF group = 19.5 ± 5 to 17.9 ± 4 µM and QF group = 17.9 ± 4 to 16.9 ± 3 µM) and an increase in urinary excretion of enterolignans (CF group = 2.05 ± 1.3 to 2.24 ± 1.4 nm/ml and QF group = 2.9 ± 1.6 to 3.2 ± 2.7 nm/l), in both study groups. The reduction of total cholesterol (191 ± 35 to 181 ± 28 mg/dl) and LDL-cholesterol (LDL-c) (129 ± 35 to 121 ± 26 mg/dl), and the increase in GSH (1.78 ± 0.4 to 1.91 ± 0.4 µmol/l) occurred only in the QF group, showing a possible beneficial effect of QF intake.

Purpose: Chronic inflammation has been implicated in the etiology of various chronic diseases. We previously found that certain urinary isoflavones are associated with markers of inflammation. In the present study, we examined the associations of serum C-reactive protein (CRP) and white blood cell (WBC) count with lignans, which are more frequent in the Western diet than isoflavones., Methods: Our analysis included 2,028 participants of NHANES 2005-2008 and 2,628 participants of NHANES 1999-2004 aged 18 years and older. The exposures of interest were urinary mammalian lignans (enterodiol and enterolactone). Outcome variables were two inflammatory markers (CRP [≤10 mg/L] and WBC [≥3.0 and ≤11.7 (1,000 cells/μL)]). Log-transformed CRP concentration and WBC count by log-transformed creatinine-standardized concentrations of mammalian lignans were used for linear regression., Results: Statistically significant inverse associations of urinary lignan, enterodiol, and enterolactone concentrations with circulating CRP and WBC counts were observed in the multivariate-adjusted models: In NHANES 2005-2008, per one-percent increase in lignan concentrations in the urine, CRP concentrations and WBC counts decreased by 8.1 % (95 % CI -11.5, -4.5) and 1.9 % (95 % CI -2.7; -1.2), respectively. Per one-percent increase in enterodiol and enterolactone, WBC counts decreased by 2.1 % (95 % CI -2.8, -1.3) and 1.3 % (95 % CI -1.9, -0.6), respectively. In NHANES 1999-2004, analogous results were 3.0 % (95 % CI -5.6, -0.3), 1.2 % (95 % CI -2.0; -0.4), 1.0 % (95 % CI -1.8, -0.2), and 0.8 % (95 % CI -1.4, 0.2)., Conclusions: Mammalian lignans were inversely associated with markers of chronic inflammation. Due to the cross-sectional design, our findings require confirmation in prospective studies.

Background: Fluctuating hormonal levels observed during the menopausal transition may increase vulnerability to depression in susceptible women. Thus, it is of interest to examine the effect of natural estrogens such as phytoestrogens on the risk of depression in perimenopausal women., Methods: Our analysis included 193 perimenopausal women of the National Health and Nutrition Survey (NHANES) 2005-2008 aged 45-55 years. Urinary concentrations of phytoestrogens (isoflavones and lignans) were measured by HPLC-APPI-MS/MS. Depression was assessed using the Patient Health Questionnaire-9 (PHQ-9). Logistic regression models examined the association of phytoestrogens concentrations (creatinine-standardized and log-transformed) with depression (yes/no)., Results: Unadjusted odds ratios (OR) of the associations between urinary phytoestrogen concentrations and perimenopausal depression were below 1; however, only lignans were significantly inversely associated with depression. The latter findings were not attenuated in multivariate analysis including age, race, body mass index, poverty income ratio, smoking, alcohol consumption, cancer, diabetes, and cardiovascular disease (lignans: OR=0.66; 95% confidence intervals (CI) 0.50-0.87, enterodiol: OR=0.63; 95% CI 0.51-0.78, enterolactone: OR=0.75; 95% CI 0.60-0.93)., Limitations: Our cross-sectional study design does not allow for causal inferences. Because information to precisely assess perimenopausal symptoms was missing, we defined perimenopause based on women's age., Conclusions: Lower lignans but not isoflavones concentrations were statistically significantly associated with an increased risk of depression in perimenopausal women. Because of medical risks associated with the use of hormone therapy, further investigation on the effect of lignans on the risk of depression in perimenopausal women is warranted., (Copyright © 2014. Published by Elsevier B.V.)

Phytoestrogens have been associated with subtle hormonal changes, although effects on fecundity are unknown. Our objective was to evaluate the association between male and female urinary phytoestrogen (isoflavone and lignan) concentrations and time to pregnancy (TTP) in a population-based cohort of 501 couples desiring pregnancy and discontinuing contraception. Couples were followed for 12 mo or until pregnancy. Fecundability ORs (FORs) and 95% CIs were estimated after adjusting for age, body mass index, race, site, creatinine, supplement use, and physical activity in relation to female, male, and joint couple concentrations. Models included the phytoestrogen of interest and the sum of the remaining individual phytoestrogens. FORs <1 denote a longer TTP and FORs >1 a shorter TTP. Urinary lignan concentrations were higher, on average, among female partners of couples who became pregnant during the study compared with women who did not become pregnant (median enterodiol: 118 vs. 80 nmol/L; P < 0.10; median enterolactone: 990 vs. 412 nmol/L; P < 0.05) and were associated with significantly shorter TTP in models based on both individual and couples' concentrations (couples' models: enterodiol FOR, 1.13; 95% CI: 1.02, 1.26; enterolactone FOR, 1.11; 95% CI: 1.01, 1.21). Male lignan concentrations were not associated with TTP, nor were isoflavone concentrations. Sensitivity analyses showed that associations observed are unlikely to be explained by potential unmeasured confounding by lifestyle or other nutrients. Our results suggest that female urinary lignan concentrations at levels characteristic of the U.S. population are associated with a shorter TTP among couples who are attempting to conceive, highlighting the importance of dietary influences on fecundity.

Secoisolariciresinol-diglycoside (SDG), a natural dietary lignan of flaxseeds now available in dietary supplements, is converted by intestinal bacteria to the mammalian lignans enterodiol and enterolactone. High levels of these lignans in blood and urine are associated with reduced risk of many chronic diseases. Our objective was to determine the bioavailability and pharmacokinetics of SDG in purified flaxseed extracts under dose-ranging and steady-state conditions, and to examine whether differences in secoisolariciresinol-diglycoside purity influence bioavailability. Pharmacokinetic studies were performed on healthy postmenopausal women after oral intake of 25, 50, 75, 86 and 172 mg of secoisolariciresinol-diglycoside. Extracts differing in secoisolariciresinol-diglycoside purity were compared, and steady-state lignan concentrations measured after daily intake for one week. Blood and urine samples were collected at timed intervals and secoisolariciresinol, enterodiol and enterolactone concentrations measured by mass spectrometry. Secoisolariciresinol-diglycoside was efficiently hydrolyzed and converted to secoisolariciresinol. Serum concentrations increased rapidly after oral intake, peaking after 5-7 h and disappearing with a plasma elimination half-life of 4.8 h. Maximum serum concentrations of the biologically active metabolites, enterodiol and enterolactone were attained after 12-24 h and 24-36 h, respectively, and the half-lives were 9.4 h and 13.2 h. Linear dose-responses were observed and secoisolariciresinol bioavailability correlated (r(2) = 0.835) with cumulative lignan excretion. There were no significant differences in the pharmacokinetics of extracts differing in purity, and steady-state serum lignan concentrations were obtained after one-week of daily dosing. In conclusion, this study defines the pharmacokinetics of secoisolariciresinol-diglycoside and shows it is first hydrolyzed and then metabolized in a time-dependent sequence to secoisolariciresinol, enterodiol and ultimately enterolactone, and these metabolites are efficiently absorbed.

Deoxyschizandrin is an active lignin ingredient originating from Schisandra chinensis (Turcz.) Baill or Schisandrae Sphenantherae Fructus. In the present study, a novel and efficient strategy was developed for the in vivo screening and identification of deoxyschizandrin metabolites using ultra high performance liquid chromatography combined with triple TOF mass spectrometry (UPLC-TOF/MS/MS). This strategy was characterized by the following: a novel and unique multiple mass defect filter (MMDF) combined with an on-line data acquisition method that is dependent on dynamic background subtraction (DBS) was developed to trace all of the probable metabolites of deoxyschizandrin. The MMDF and DBS methods could trigger an IDA scan for the low-level metabolites that are masked by background noise and endogenous components. A combination of data processing methods including extracted ion chromatography (XIC), mass defect filtering (MDF), product ion filtering (PIF) and neutral loss filtering (NLF) were employed to identify the metabolites of deoxyschizandrin. Next, the structures of the metabolites were elucidated based on an accurate mass measurement, the fragmentation patterns of the parent drug and relevant drug bio-transformation knowledge. Finally, an important parameter ClogP was used to estimate the retention time of isomers. Based on the proposed strategy, 51 metabolites (including 49 phase I and 2 phase II metabolites) were identified in rats after the oral administration of deoxyschizandrin. Among these metabolites, 41 metabolites were characterized in the rat urine, and 28 metabolites were identified in the rat bile. The results indicated that oxidization was the main metabolic pathway and that the methoxy group and the biphenyl cyclooctene were the metabolic sites. Conjugation with sulfate and cysteine groups produced two phase-II metabolites. This study firstly reported the description of deoxyschizandrin metabolism in vivo. This study provided a practical strategy for rapidly screening and identifying metabolites, and this methodology can be widely applied for the structural characterization of the metabolites of other compounds., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Use of complementary approaches is common among breast cancer survivors. Potential interactions between aromatase inhibitors (AI) and high phytoestrogen foods, such as flaxseed (FS), are not often described. We conducted a pilot 2 × 2 factorial, randomized intervention study between tumor biopsy and resection, in 24 postmenopausal women with estrogen receptor positive (ER+) breast cancer, to assess the effects of FS and anastrozole, and possible interactions between them, on serum steroid hormone and tumor-related characteristics associated with long-term survival (Roswell Park Cancer Institute, 2007-2010). The effect of each treatment vs. placebo on outcomes was determined by linear regression adjusting for pretreatment measure, stage, and grade. Although not statistically significant, mean ERβ expression was approximately 40% lower from pre- to postintervention in the FS + AI group only. We observed a statistically significant negative association (β ± SE -0.3 ± 0.1; P = 0.03) for androstenedione in the FS + AI group vs. placebo and for DHEA with AI treatment (β ± SE -1.6 ± 0.6; P = 0.009). Enterolactone excretion was much lower in the FS + AI group compared to the FS group. Our results do not support strong effects of FS on AI activity for selected breast tumor characteristics or serum steroid hormone levels but suggest AI therapy might reduce the production of circulating mammalian lignans from FS.

Many healthy phytochemicals occur in food in the form of esters, glycoconjugates, or polymers, which are not directly bioavailable. Probiotic lactobacilli and bifidobacteria, which have evolved within the colonic ecosystem where indigestible oligo- and polysaccharides are their sole carbon sources, bear several glycosyl-hydrolases and can contribute to release the aglycones from glycoconjugated phytochemicals. Among the glycosyl-hydrolases, β-glucosidases are the most pertinent, because many phytochemicals are glucoconjugates. β-Glucosidase-positive probiotic bacteria were proved to release the aglycones of isoflavones and lignans in vitro, but studies in vivo are scarce. A positive correlation between probiotic consumption and urinary and/or plasma levels of isoflavone or lignan metabolites was not established. However, the strains used in the trials were not validated for the enzymatic properties or for the ability to hydrolyze lignans or isoflavones. Thus, activation of specific phytochemicals by probiotic bacteria still needs substantial efforts to be proved.

Phytoestrogens (PEs) are naturally occurring chemical constituents of certain plants. The internal PE exposures, mainly from diet, vary among different populations and in different regions due to various eating habits. To investigate the potential relationship between urinary PE levels and idiopathic male infertility and semen quality in Chinese adult males, 608 idiopathic infertile men and 469 fertile controls were recruited by eligibility screening procedures. Individual exposure to PEs was measured using UPLC-MS/MS as spot urinary concentrations of 6 PEs (daidzein, DAI; equol, EQU; genistein, GEN; naringenin, NAR; coumestrol, COU; and secoisolariciresinol, SEC), which were adjusted with urinary creatinine (CR). Semen quality was assessed by sperm concentration, number per ejaculum and motility. We found that exposures to DAI, GEN and SEC were significantly associated with idiopathic male infertility (P-value for trend=0.036; 0.002; and 0.0001, respectively), while these exposures had stronger association with infertile subjects with at least one abnormal semen parameter than those with all normal semen parameters. Exposures to DAI, GEN and SEC were also related to idiopathic male infertility with abnormal sperm concentration, number per ejaculum and motility (P-value for trend<0.05), while these exposures had stronger association with the infertile men with abnormal sperm number per ejaculum. These findings provide the evidence that PE exposures are related to male reproductive function and raise a public health concern because that exposure to PEs is ubiquitous in China., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Objectives: High consumption of soybean products has been associated with a reduced risk of hormone-sensitive tumors. Soybean products contain phytoestrogens, such as daidzein, and sesame seeds contain secoisolariciresinol. These compounds are further metabolized to equol, enterodiol, and enterolactone by intestinal bacteria. However, individual differences in the metabolizing potential remain unclear. The aim of this study was to evaluate the urinary daidzein, equol, enterodiol, and enterolactone concentrations in women from several different regions of Japan according to age group., Methods: Five hundred urine samples collected from Japanese women living in Sapporo, Sendai, Kyoto, Kochi, and Naha were analyzed for daidzein, equol, enterodiol, and enterolactone concentration by gas chromatography-mass spectrometry., Results: The urinary isoflavone and lignan polyphenol levels did not differ significantly among the sampling sites, except for daidzein, which was highest in urine collected at Naha. The prevalence of equol producers was 39 % in the total study cohort. In equol producers, a positive correlation was observed between the urinary daidzein and equol levels (r = 0.399, p < 0.001). However, there was no significant difference between daidzein concentrations in equol producers and non-producers. Moreover, the levels of enterodiol and enterolactone were higher in equol producers than in equol non-producers. In the multivariate logistic analyses, two factors, Sendai dwelling and current smoking, were found to be significant [equol producers to non-producers: odds ratio 2.15 (95 % confidence interval: 1.17-4.02) and odds ratio 0.32 (0.15-0.63), respectively]., Conclusions: Our data suggest that geographic factors and smoking status should be considered during the evaluation of equol in urine samples and that the same pathway may be responsible for the metabolism of both isoflavones and lignan polyphenols.

The gut microbial environment (bacteria and metabolites) may have a role in obesity. Urinary enterolignan concentrations can provide a marker of interindividual differences in microbial environments. Analysis was conducted on 6806 individuals from 2003 to 2008 National Health and Nutrition Examination Survey data, and weight status, waist circumference groups and high- vs low-enterolignan concentration was evaluated using multinomial logistic regression, adjusted for personal and dietary factors. High-enterolignan concentrations were defined as the 90th percentile value and greater. High-enterodiol concentration was associated with 18% and 42% lower likelihood of being overweight and obese, respectively, and 48% lower likelihood of having high-risk waist circumference among adults. High-enterolactone concentration was associated with 24% and 64% lower likelihood of being overweight and obese, respectively. Age and sex were not modifiers of these associations. These results from a large human study population provide additional evidence supporting the microbiome-obesity relationship.

Lignans and flavonols are dietary phytoestrogens found at high concentrations in the Western Diet. They have potential to influence the timing of puberty. We hypothesized that greater consumption of these 2 phytoestrogens would be related to later age at pubertal onset among girls. Pubertal assessment and 24-hour diet recall data were available for 1178 girls, ages 6 to 8 years (mean 7.3 years) in the Breast Cancer and Environment Research Project Puberty Study. Lignan and flavonol intakes were mainly derived from fruit and vegetable consumption. Average consumption was 6.5 mg/d for flavonols and 0.6 mg/d for lignans. Highest flavonol consumption (>5 mg/d) was associated with later breast development (adjusted hazards ratio [HR]: 0.74, 95% CI: [0.61-0.91]) compared to 2 to 5 mg/d (adjusted HR: 0.84, 95% CI: [0.70-1.0]) and <2 mg/d (referent group; P-trend = .006). Flavonol intake was not associated with pubic hair development. Lignan intake was not associated with either breast or pubic hair development. Dietary intake was only weakly correlated with urinary enterolactone, a biomarker for lignans (RS = 0.13). Consistent with biologic properties of phytoestrogens that indicate hormonal activity, their consumption may be associated with reproductive end points, even in childhood., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Isoflavones and lignans are plant-derived dietary compounds generally believed to be beneficial to human health. We investigated the extent to which sociodemographic (age, sex, race-ethnicity, education, and income) and lifestyle variables (smoking, alcohol consumption, BMI, physical activity, and dietary supplement use) were correlates of spot urine concentration for daidzein, genistein, O-desmethylangolensin (DMA), equol, enterodiol, and enterolactone in the U.S. population aged ≥ 20 y (NHANES 2003-2006). We performed correlation analyses with continuous variables and calculated stratified unadjusted geometric means for each sociodemographic and lifestyle variable. We used bivariate significance testing and covariate adjustment by use of multiple regression models to identify influential variables and used β coefficients to estimate relative effects. Urine creatinine was also included in our analyses because of its use in correcting for variable dilution in spot urine samples. We observed many significant (P < 0.05) associations with the sociodemographic and lifestyle variables that withstood covariate adjustment. Smoking was a significant correlate of urine DMA and enterolactone, with concentrations at least 25% lower in smokers vs. nonsmokers. Consumers of 1 daily alcoholic drink vs. none were estimated to have 18-21% lower urine equol and DMA concentrations. A 25% increase in BMI was associated with a 21% lower urine enterolactone concentration, and increasing physical activity was associated with a >6% higher urine enterolactone concentration. Dietary supplement use was not significantly associated with any of the urine phytoestrogens. Overall, we found that relationships between sociodemographic and lifestyle variables and urine phytoestrogen concentration were highly compound and class specific.

Enterolactone and enterodiol, mammalian lignans derived from dietary sources such as flaxseed, sesame seeds, kale, broccoli, and apricots, may impede tumor proliferation by inhibiting activation of nuclear factor kappa B (NFκB) and vascular endothelial growth factor (VEGF). We examined the associations between urinary enterolactone and enterodiol with prostatic tumor expression of NFκB, VEGF, and Ki67 among 147 patients with prostate cancer who participated in a presurgical trial of flaxseed supplementation (30 g/day) for ~30 days. Urinary enterolignans and tissue biomarkers were determined by high-performance liquid chromatography and immunohistochemistry, respectively. After supplementation, we observed significant correlations between intakes of plant lignan and urinary concentrations of total enterolignans (ρ=0.677, P<.0001), enterolactone (ρ=0.676, P<.0001), and enterodiol (ρ=0.628, P<.0001). Importantly, we observed that total urinary enterolignans and enterolactone were significantly and inversely correlated with Ki67 in the tumor tissue (ρ=-0.217, P=.011, and ρ=-0.230, P=.007, respectively), and a near-significant inverse association was observed for enterodiol (ρ=-0.159, P=.064). An inverse association was observed between enterolactone and VEGF (ρ=-0.143, P=.141), although this did not reach statistical significance. We did not observe an association between enterolignans and NFκB. In conclusion, flaxseed-derived enterolignans may hinder cancer cell proliferation via VEGF-associated pathways.

Arctiin, an important lignan compound in Fructus Arctii, has been reported to possess various kinds of bioactivities. Previous studies on the pharmacokinetic of arctiin after oral administration showed that it had a rapid absorption phase followed by a sharp but lasting disappearance. To gain deep insight into the action mechanism of arctiin, the excretion and metabolism of arctiin in vivo should be further studied. In this paper, three metabolites were isolated and identified in rat feces as (-)-enterolactone (M-1), (-)-arctigenin (M-2) and [(2R,3R)-2-(3'-hydroxybenzyl)-3-(3″,4″-dimethoxybenzyl)-butyrolactone] (M-3). Based on the structures of three metabolites, possible metabolic pathways of arctiin in rats are proposed. At the same time, the cumulative excretion rate of arctiin and its metabolites in rat urine and feces were determined, indicating that arctiin was excreted 19.84% in urine and 1.80% in feces, respectively, enterolactone, the most main metabolite, was excreted 35.80% in feces. These results provide very important information for understanding the metabolism and excretion of arctiin in vivo and speculating its action mechanism, they can provide useful information and reference for further metabolic investigations on arctiin in humans., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Scope: Non-targeted urine metabolite profiling has not been previously exploited in the field of whole grain (WG) products. WG products, particularly rye, are important elements in a healthy Nordic diet. The aim of this study was to identify novel urinary biomarkers of WG rye bread (RB) intake in a randomised crossover study with RB versus refined wheat bread (WB)., Methods and Results: UPLC-QTOF/MS metabolite profiling was applied to urine from a 2 × 4 wk crossover intervention with RB versus WB in 20 subjects. Sixteen metabolites were revealed as major contributing biomarkers. The most discriminative metabolite after the cereal intervention was identified as 3-(3,5-dihydroxyphenyl)-1-propanoic acid sulphate, which was excreted to a higher extent after the RB versus WB intervention. Other alkylresorcinol metabolites were identified, as well as enterolactone glucuronide, azelaic acid, 2-aminophenol sulphate and its benzoxazinoid precursor 2,4-dihydroxy-1,4-benzoxazin-3-one. Our study also suggests that nitrogen-containing metabolites are other major markers. However, other methodologies will be needed to elucidate their final structure., Conclusion: The present non-targeted metabolite profiling proved to be a useful approach to identify major urine metabolites discriminating RB intake from that of white wheat bread. Once validated these markers could help evaluate compliance to healthy Nordic diets., (© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Ruminal microbiota plays an important role in the conversion of plant lignans into mammalian lignans. The main mammalian lignan present in the milk of dairy cows fed flax products is enterolactone (EL). The objectives of the present study were to investigate the effects of abomasal infusion of flax oil on the metabolism of flax lignans and concentrations of EL in biological fluids of dairy cows. A total of six rumen-cannulated dairy cows were assigned within a 2 × 3 factorial arrangement of six treatments utilising flax hulls (0 and 15·9 % of DM) and abomasal infusion of flax oil (0, 250 and 500 g/d). There were six periods of 21 d each. Samples were collected during the last 7 d of each period and subjected to chemical analysis. Flax hull supplementation increased concentrations of EL in ruminal fluid, plasma, urine and milk, while flax oil infusion had no effect. Post-feeding, β-glucuronidase activity in the ruminal fluid of cows infused with 250 g flax oil was significantly lower for cows fed hulls than for those fed the control diet. The present study demonstrated that the presence of a rich source of n-3 fatty acids such as flax oil in the small intestine does not interfere with the absorption of the mammalian lignan EL and that lower ruminal β-glucuronidase activity had no effect on the conversion of flax lignans into EL in the rumen of dairy cows.

Background/aims: A deficit of various hormones during the process of aging and/or a heightened inflammatory state may be causally linked to the development of frailty. Phytoestrogens as weak estrogens, antioxidants, and anti-inflammatory agents may counteract this process., Methods: In a cross-sectional study including two cycles of the National Health and Nutrition Examination Survey (NHANES, i.e. 1999-2002), logistic regression was used to analyze the association between urinary concentrations of isoflavones and lignans and frailty in 600 females aged 50 years or older (median age 66.5 years). Participants were classified as 'frail' (meeting 3 or more of the 5 frailty criteria), 'prefrail' (meeting 1 or 2 of the criteria), or 'robust' (meeting none of the criteria). Four percent were frail., Results: For all of the phytoestrogens considered, the unadjusted OR were lower than 1 but generally not statistically significant aside from the association with O-desmethylangolensin (O-DMA) (OR = 0.76; 95% CI 0.61-0.92). Multivariate analysis did not attenuate this finding (OR = 0.74; 95% CI 0.61-0.90)., Conclusions: This first analysis of the relationship between phytoestrogens and frailty revealed an inverse association between urinary O-DMA levels and frailty in women. However, the number of frail women was low. Although this finding may be confounded or biased, it seems worthwhile to intensify research on the potential preventive effects of O-DMA.

Some clinical trials have shown that high phytoestrogen intake may decrease serum concentrations of prostate-specific antigen (PSA), and phytoestrogens may also lower prostate cancer risk. It was the aim of this study to examine the relationship between the serum PSA level and urine phytoestrogen concentration in generally healthy U.S. men. Eight hundred twenty-four men, 40+ yr old without prostate cancer, who participated in the 2001-2004 NHANES surveys, were included in the analysis. The association of total PSA, free PSA, and PSA ratio [free PSA/total PSA * 100] with concentrations of isoflavones and lignans (standardized for urinary creatinine concentration) was examined using multivariable-adjusted linear and logistic regression models. The linear regression analyses showed no clear association between creatinine-standardized urinary phytoestrogen concentrations and serum total or free PSA levels or PSA ratio. However, the odds of having a PSA ratio <15% rose from Quartile 1 to Quartile 4 of isoflavone excretion (odds ratio = 2.82, 95% confidence interval 1.28-6.22 for top vs. bottom quartile), but there were no associations with having a PSA ratio <25%. In generally healthy U.S. men, 40+ yr old without a diagnosis of prostate cancer, urinary isoflavone, and lignan concentrations were not associated with serum PSA level.