Chronic inflammation and gut barrier breakdown contribute to the progression of metabolic syndrome and affect the development of cardiometabolic diseases, especially in persons consuming low-quality diets with limited bioactive compounds. Almonds are a rich source of bioactive compounds with antioxidant and anti-inflammatory properties. We hypothesize almond consumption can help disrupt metabolic syndrome progression by improving gut and cardiometabolic health and decreasing inflammation and oxidative stress. To test this hypothesis, adults with metabolic syndrome were randomized to consume either almonds (2 oz, whole, dry roasted, n = 38) or crackers (control, equal caloric content, n = 39), as a daily snack for 12 weeks, and samples were collected (0, 4, and 12 weeks). Compared with participants consuming crackers, almond consumption resulted in lower plasma total and low-density lipoprotein-cholesterol concentrations, a modest improvement in waist circumference (week 4), and improved dietary intakes of α-tocopherol, soluble fiber, copper, biotin, magnesium, polyunsaturated fatty acids, and monounsaturated fatty acids. Almond consumption raised plasma α-tocopherol concentrations (relative to cholesterol concentrations) and increased excretion of a vitamin E biomarker (α-CEHC). Almond consumption improved biomarkers of gut barrier function and intestinal inflammation (fecal calprotectin, myeloperoxidase) in participants with elevated inflammation at baseline. Total body weight, caloric intake, and markers of carbohydrate metabolism (glucose, insulin), systemic inflammation (plasma interleukin-6, C-reactive protein, lipopolysaccharide-binding protein, CD14), and oxidative damage (malondialdehyde) were not altered by almond consumption. In conclusion, daily almond snacking improves nutrient intake and decreases gut inflammation in participants with metabolic syndrome. These beneficial dietary and inflammatory changes may contribute to the improvements in cardiovascular health observed.
Per- and polyfluoroalkyl substances (PFAS) are a widespread and persistent class of contaminants posing significant environmental and human health concerns. Comprehensive understanding of the modes of action underlying toxicity among structurally diverse PFAS is mostly lacking. To address this need, we recently reported on our application of developing zebrafish to evaluate a large library of PFAS for developmental toxicity. In the present study, we prioritized 15 bioactive PFAS that induced significant morphological effects and performed RNA-sequencing to characterize early transcriptional responses at a single timepoint (48 h post fertilization) after early developmental exposures (8 h post fertilization). Internal concentrations of 5 of the 15 PFAS were measured from pooled whole fish samples across multiple timepoints between 24–120 h post fertilization, and additional temporal transcriptomics at several timepoints (48–96 h post fertilization) were conducted for Nafion byproduct 2. A broad range of differentially expressed gene counts were identified across the PFAS exposures. Most PFAS that elicited robust transcriptomic changes affected biological processes of the brain and nervous system development. While PFAS disrupted unique processes, we also found that similarities in some functional head groups of PFAS were associated with the disruption in expression of similar gene sets. Body burdens after early developmental exposures to select sulfonic acid PFAS, including Nafion byproduct 2, increased from the 24–96 h post fertilization sampling timepoints and were greater than those of sulfonamide PFAS of similar chain lengths. In parallel, the Nafion byproduct 2-induced transcriptional responses increased between 48 and 96 h post fertilization. PFAS characteristics based on toxicity, transcriptomic effects, and modes of action will contribute to further prioritization of PFAS structures for testing and informed hazard assessment.
Introduction: The space environment astronauts experience during space missions consists of multiple environmental challenges, including microgravity. In this study, we assessed the behavioral and cognitive performances of male Fisher rats 2 months after sham irradiation or total body irradiation with photons in the absence or presence of simulated microgravity. We analyzed the plasma collected 9 months after sham irradiation or total body irradiation for distinct alterations in metabolic pathways and to determine whether changes to metabolic measures were associated with specific behavioral and cognitive measures.Methods: A total of 344 male Fischer rats were irradiated with photons (6 MeV; 3, 8, or 10 Gy) in the absence or presence of simulated weightlessness achieved using hindlimb unloading (HU). To identify potential plasma biomarkers of photon radiation exposure or the HU condition for behavioral or cognitive performance, we performed regression analyses.Results: The behavioral effects of HU on activity levels in an open field, measures of anxiety in an elevated plus maze, and anhedonia in the M&M consumption test were more pronounced than those of photon irradiation. Phenylalanine, tyrosine, and tryptophan metabolism, and phenylalanine metabolism and biosynthesis showed very strong pathway changes, following photon irradiation and HU in animals irradiated with 3 Gy. Here, 29 out of 101 plasma metabolites were associated with 1 out of 13 behavioral measures. In the absence of HU, 22 metabolites were related to behavioral and cognitive measures. In HU animals that were sham-irradiated or irradiated with 8 Gy, one metabolite was related to behavioral and cognitive measures. In HU animals irradiated with 3 Gy, six metabolites were related to behavioral and cognitive measures.Discussion: These data suggest that it will be possible to develop stable plasma biomarkers of behavioral and cognitive performance, following environmental challenges like HU and radiation exposure.
IntroductionEffects and interactions between different spaceflight stressors are expected to be experienced by crew on missions when exposed to microgravity and galactic cosmic rays (GCRs). One of the limitations of previous studies on simulated weightlessness using hindlimb unloading (HU) is that a control HU condition was not included.MethodsWe characterized the behavioral performance of male Fischer rats 2 months after sham or total body irradiation with a simplified 5-ion 6-mixed-beam exposure representative of GCRs in the absence or presence of HU. Six months later, the plasma, hippocampus, and cortex were processed to determine whether the behavioral effects were associated with long-term alterations in the metabolic pathways.ResultsIn the open field without and with objects, interactions were observed for radiation × HU. In the plasma of animals that were not under the HU or control HU condition, the riboflavin metabolic pathway was affected most for sham irradiation vs. 0.75 Gy exposure. Analysis of the effects of control HU on plasma in the sham-irradiated animals showed that the alanine, aspartate, glutamate, riboflavin, and glutamine metabolisms as well as arginine biosynthesis were affected. The effects of control HU on the hippocampus in the sham-irradiated animals showed that the phenylalanine, tyrosine, and tryptophan pathway was affected the most. Analysis of effects of 0.75 Gy irradiation on the cortex of control HU animals showed that the glutamine and glutamate metabolic pathway was affected similar to the hippocampus, while the riboflavin pathway was affected in animals that were not under the control HU condition. The effects of control HU on the cortex in sham-irradiated animals showed that the riboflavin metabolic pathway was affected. Animals receiving 0.75 Gy of irradiation showed impaired glutamine and glutamate metabolic pathway, whereas animals receiving 1.5 Gy of irradiation showed impaired riboflavin metabolic pathways. A total of 21 plasma metabolites were correlated with the behavioral measures, indicating that plasma and brain biomarkers associated with behavioral performance are dependent on the environmental conditions experienced.DiscussionPhenylalanine, tyrosine, and tryptophan metabolism as well as phenylalanine and tryptophan as plasma metabolites are biomarkers that can be considered for spaceflight as they were revealed in both Fischer and WAG/Rij rats exposed to simGCRsim and/or HU.
The unpredictable biodegradation of fluorotelomer (FT)-based per- and polyfluoroalkyl substances (PFAS) causes complicated risk management of PFAS-impacted sites. Here, we have successfully used redundancy analysis to link FT-based precursor biodegradation to key microbes and genes of soil microbiomes shaped by different classes of carbon sources: alcohols (C2-C4), alkanes (C6 and C8), an aromatic compound (phenol), or a hydrocarbon surfactant (cocamidopropyl betaine [CPB]). All the enrichments defluorinated fluorotelomer alcohols (n:2 FtOH; n = 4, 6, 8) effectively and grew on 6:2 fluorotelomer sulfonate (6:2 FtS) as a sulfur source. The butanol-enriched culture showed the highest defluorination extent for FtOHs and 6:2 FtS due to the high microbial diversity and the abundance of desulfonating and defluorinating genes. The CPB-enriched culture accumulated more 5:3 fluorotelomer carboxylic acid, suggesting unique roles of Variovorax and Pseudomonas. Enhanced 6:2 FtOH defluorination was observed due to a synergism between two enrichments with different carbon source classes except for those with phenol- and CPB-enriched cultures. While the 6:2 fluorotelomer sulfonamidoalkyl betaine was not degraded, trace levels of 6:2 fluorotelomer sulfonamidoalkyl amines were detected. The identified species and genes involved in desulfonation, defluorination, and carbon source metabolism are promising biomarkers for assessing precursor degradation at the sites.
VacciniumL., a globally distributed genus, encompasses economically and nutritionally valuable species such as blueberry ( V. corymbosumL. and its hybrids), cranberry ( V. macrocarponA.), bilberry ( V. myrtillusL.), and lingonberry ( V. vitis-ideaL.). There has been a robust growth of blueberry cultivation in the tropical and subtropical regions of the world, such as Central and South America, the Southern United States, Australia, and the Mediterranean. This growth has been enabled by the integration of various wild species such as northern lowbush blueberry V. angustifolium(Aiton), evergreen blueberry V. darrowii(Camp), and rabbiteye blueberry V. virgatum(Aiton) into highbush blueberry breeding programs. Still, numerous under-studied wild Vacciniumspecies have untapped potential for breeding use and local cultivation in diverse climates. The harvest of wild Vacciniumfruit has long contributed to the nutrition of local communities throughout Southeast Asia and the Americas. Our objective was to conduct preliminary investigations into the fruit qualities and anthocyanin profiles of two such under-studied species, V. myrtoides(Blume) and V. floribundum(Kunth), and compare their characteristics to that of the southern highbush blueberry cultivar ‘O’Neal’ ( V. corymbosumhybrid). Over the spring and summer of 2021, we determined fruit size, percent soluble solids, pH, total anthocyanin concentration, and anthocyanin aglycons profiles. The fruit was sourced from the US Department of Agriculture (USDA), National Clonal Germplasm Repository (NCGR) in Corvallis, Oregon. The wild species’ fruit size, soluble solids, and pH were not significantly different from those of ‘O’Neal.’ The total anthocyanin levels for V. floribundum(87.4 mg anthocyanin/100 g frozen fruit) and V. myrtoides(80.4 mg/100 g frozen fruit) were significantly higher than those for ‘O’Neal’ (32 mg/100 g frozen fruit). Anthocyanin profiles were also unique to each species. V. myrtoideshad the most complex profile with eight anthocyanin peaks; V. floribundumhad four peaks ‘O’Neal’ had three. One of the most prominent anthocyanins in blueberries, petunidin-3- galactoside, occurred in ‘O’Neal’ and V. myrtoidesbut was absent from V. floribundum. Del-3-arabinoside was present in both V. myrtoidesand V. floribundumyet absent in ‘O’Neal’. The unique anthocyanin profiles of the two wild species could have value in diversifying the anthocyanins available in cultivated blueberries and deserve further investigation.
Muscle wasting occurs with aging and may be a result of oxidative stress damage and potentially inadequate protection by lipophilic antioxidants, such as vitamin E. Previous studies have shown muscular abnormalities and behavioral defects in vitamin E-deficient adult zebrafish. To test the hypothesis that there is an interaction between muscle degeneration caused by aging and oxidative damage caused by vitamin E deficiency, we evaluated long-term vitamin E deficiency in the skeletal muscle of aging zebrafish using metabolomics. Zebrafish (55 days old) were fed E+ and E− diets for 12 or 18 months. Then, skeletal muscle samples were analyzed using UPLC-MS/MS. Data were analyzed to highlight metabolite and pathway changes seen with either aging or vitamin E status or both. We found that aging altered purines, various amino acids, and DHA-containing phospholipids. Vitamin E deficiency at 18 months was associated with changes in amino acid metabolism, specifically tryptophan pathways, systemic changes in the regulation of purine metabolism, and DHA-containing phospholipids. In sum, while both aging and induced vitamin E deficiency did have some overlap in altered and potentially dysregulated metabolic pathways, each factor also presented unique alterations, which require further study with more confirmatory approaches.
Although vitamin E acetate (VEA) is suspected to play a causal role in the development of electronic-cigarette, or vaping, product use-associated lung injury (EVALI), the underlying biological mechanisms of pulmonary injury are yet to be determined. In addition, no study has replicated the systemic inflammation observed in humans in a murine EVALI model, nor investigated potential additive toxicity of viral infection in the setting of exposure to vaping products. To identify the mechanisms driving VEA-related lung injury and test the hypothesis that viral infection causes additive lung injury in the presence of aerosolized VEA, we exposed mice to aerosolized VEA for extended times, followed by influenza infection in some experiments. We used mass spectrometry to evaluate the composition of aerosolized VEA condensate and the VEA deposition in murine or human alveolar macrophages. Extended vaping for 28 days versus 15 days did not worsen lung injury but caused systemic inflammation in the murine EVALI model. Vaping plus influenza increased lung water compared with virus alone. Murine alveolar macrophages exposed to vaped VEA hydrolyzed the VEA to vitamin E with evidence of oxidative stress in the alveolar space and systemic circulation. Aerosolized VEA also induced cell death and chemokine release and reduced efferocytotic function in human alveolar macrophages in vitro. These findings provide new insights into the biological mechanisms of VEA toxicity.
Background: Numerous abnormalities in cystic fibrosis (CF) could influence tocopherol absorption, transportation, storage, metabolism and excretion. We hypothesized that the oxidative distress due to inflammation in CF increases vitamin E utilization, which could be positively influenced by supplemental vitamin C administration. Methods: Immediately before and after receiving vitamin C (500 mg) twice daily for 3.5 weeks, adult CF patients (n = 6) with moderately advanced respiratory tract (RT) disease consumed a standardized breakfast with 30% fat and a capsule containing 50 mg each hexadeuterium (d6)-α- and dideuterium (d2)-γ-tocopheryl acetates. Blood samples were taken frequently up to 72 h; plasma tocopherol pharmacokinetics were determined. During both trials, d6-α- and d2-γ-tocopherols were similarly absorbed and reached similar maximal plasma concentrations ~18–20 h. As predicted, during vitamin C supplementation, the rates of plasma d6-α-tocopherol decline were significantly slower. Conclusions: The vitamin C-induced decrease in the plasma disappearance rate of α-tocopherol suggests that vitamin C recycled α-tocopherol, thereby augmenting its concentrations. We conclude that some attention should be paid to plasma ascorbic acid concentrations in CF patients, particularly to those individuals with more advanced RT inflammatory disease and including those with severe exacerbations.
An evaluation of the impact of vitamin E deficiency on expression of the alpha-tocopherol transfer protein (alpha-TTP) and related CRAL_TRIO genes was undertaken using livers from adult zebrafish based on the hypothesis that increased lipid peroxidation would modulate gene expression. Zebrafish were fed either a vitamin E sufficient (E + ) or deficient (E-) diet for 9 months, then fish were euthanized, and livers were harvested. Livers from the E + relative to E- fish contained 40-times more alpha-tocopherol (P < 0.0 0 01) and one fourth the malondialdehyde (P = 0.0153). RNA was extracted from E + and E- livers, then subject to evaluation of gene expression of ttpa and other genes of the CRAL_TRIO family, genes of antioxidant markers, and genes related to lipid metabolism. Ttpa expression was not altered by vitamin E status. However, one member of the CRAL_TRIO family, tyrosine-protein phosphatase non-receptor type 9 gene (ptpn9a), showed a 2.4-fold increase (P = 0.029) in E- relative to E + livers. Further, we identified that the gene for choline kinase alpha (chka) showed a 3.0-fold increase (P = 0.010) in E- livers. These outcomes are consistent with our previous findings that show vitamin E deficiency increased lipid peroxidation causing increases in phospholipid turnover. (C) 2021 Elsevier Inc. All rights reserved.
3,3\u0027-Diindolylmethane (DIM), a major phytochemical derived from ingestion of cruciferous vegetables, is also a dietary supplement. In preclinical models, DIM is an effective cancer chemopreventive agent and has been studied in a number of clinical trials. Previous pharmacokinetic studies in preclinical and clinical models have not reported DIM metabolites in plasma or urine following oral dosing and the pharmacological actions of DIM on target tissues is assumed to be solely via the parent compound. Seven subjects (6 males and 1 female) ranging from 26-65 years of age, on a cruciferous vegetable-restricted diet prior to and during the study, took 2 BioResponse-DIM ® 150 mg capsules (45.3 mg DIM/capsule) every evening for one week with a final dose the morning of the first blood draw. A complete time course was performed with plasma and urine collected over 48 hours and analyzed by UPLC-MS/MS. In addition to parent DIM, two mono-hydroxylated metabolites and 1 di-hydroxylated metabolite, along with their sulfate and glucuronide conjugates, were present in both plasma and urine. Results reported here are indicative of significant phase 1 and phase 2 metabolism and differ from previous pharmacokinetic studies in rodents and humans which reported only parent DIM present following oral administration. 2-Ox-DIM, identified as one of the mono-hydroxylated products, exhibited greater potency and efficacy as an AHR agonist when tested in an XRE-luciferase reporter assay using Hepa1 cells. In addition to competitive phytochemical-drug adverse reactions, additional metabolites may exhibit pharmacological activity highlighting the importance of further characterization of DIM metabolism in humans. Significance Statement 3,3\u0027-Diindolylmethane (DIM), derived from indole-3-carbinol in cruciferous vegetables, is an effective cancer chemopreventive agent in pre-clinical models and a popular dietary supplement currently in clinical trials. Pharmacokinetic studies to date found little or no metabolites in plasma or urine. In marked contrast, we demonstrate rapid appearance of mono- and di-hydroxylated metabolites in human plasma and urine as well as sulfate and glucuronide conjugates. 2-Ox-DIM exhibited significant AHR agonist activity emphasizing the need for characterization of pharmacological properties of DIM metabolites.
A limitation of simulated space radiation studies is that radiation exposure is not the only environmental challenge astronauts face during missions. Therefore, we characterized behavioral and cognitive performance of male WAG/Rij rats 3 months after sham-irradiation or total body irradiation with a simplified 5-ion mixed beam exposure in the absence or presence of simulated weightlessness using hindlimb unloading (HU) alone. Six months following behavioral and cognitive testing or 9 months following sham-irradiation or total body irradiation, plasma and brain tissues (hippocampus and cortex) were processed to determine whether the behavioral and cognitive effects were associated with long-term alterations in metabolic pathways in plasma and brain. Sham HU, but not irradiated HU, rats were impaired in spatial habituation learning. Rats irradiated with 1.5 Gy showed increased depressive-like behaviors. This was seen in the absence but not presence of HU. Thus, HU has differential effects in sham-irradiated and irradiated animals and specific behavioral measures are associated with plasma levels of distinct metabolites 6 months later. The combined effects of HU and radiation on metabolic pathways in plasma and brain illustrate the complex interaction of environmental stressors and highlights the importance of assessing these interactions.
Vitamin E (α-tocopherol, VitE) was discovered as a nutrient essential to protect fetuses, but its molecular role in embryogenesis remains undefined. We hypothesize that the increased lipid peroxidation due to VitE deficiency drives a complex mechanism of overlapping biochemical pathways needed to maintain glutathione (GSH) homeostasis that is dependent on betaine and its methyl group donation. We assess amino acids and thiol changes that occur during embryogenesis [12, 24 and 48 h post fertilization (hpf)] in VitE-sufficient (E+) and deficient (E−) embryos using two separate, novel protocols to quantitate changes using UPLC-MS/MS. Using partial least squares discriminant analysis, we found that betaine is a critical feature separating embryos by VitE status and is higher in E− embryos at all time points. Other important features include: glutamic acid, increased in E− embryos at 12 hpf; choline, decreased in E− embryos at 24 hpf; GSH, decreased in E− embryos at 48 hpf. By 48 hpf, GSH was significantly lower in E− embryos (P < 0.01), as were both S-adenosylmethionine (SAM, P < 0.05) and S-adenosylhomocysteine (SAH, P < 0.05), while glutamic acid was increased (P < 0.01). Since GSH synthesis requires cysteine (which was unchanged), these data suggest that both the conversion of homocysteine and the uptake of cystine via the Xc– exchanger are dysregulated. Our data clearly demonstrates the highly inter-related dependence of methyl donors (choline, betaine, SAM) and the methionine cycle for maintenance of thiol homeostasis. Additional quantitative flux studies are needed to clarify the quantitative importance of these routes.
BACKGROUND:Human vitamin E (α-tocopherol) catabolism is a mechanism for regulating whole-body α-tocopherol. OBJECTIVES:To determine the roles of the intestine and liver on α-tocopherol catabolism as affected by fat or fasting, 2 deuterium-labeled (intravenous d6- and oral d3-) forms of α-tocopherol were used. METHODS:Healthy women received intravenous d6-α-tocopherol and consumed d3-α-tocopherol with a 600-kcal defined liquid meal (DLM; 40% or 0% fat, n = 10) followed by controlled meals; or the 0% fat DLM (n = 7) followed by a 12-h fast (0% fat-fast), then controlled meals ≤72 h. The order of the 3-phase crossover design was not randomized and there was no blinding. Samples were analyzed by LC/MS to determine the α-tocopherol catabolites and α-carboxyethyl hydroxychromanol (α-CEHC) in urine, feces, and plasma that were catabolized from administered oral d3- and intravenous d6-α-tocopherols. RESULTS:Urinary and plasma d3- and d6-α-CEHC concentrations varied differently with the interventions. Mean ± SEM cumulative urinary d6-α-CEHC derived from the intravenous dose excreted over 72 h during the 40% fat (2.50 ± 0.37 μmol/g creatinine) and 0% fat (2.37 ± 0.37 μmol/g creatinine) interventions were similar, but a ∼50% decrease was observed during the 0% fat-fast (1.05 ± 0.39 μmol/g creatinine) intervention (compared with 0% fat, P = 0.0005). Cumulative urinary d3-α-CEHC excretion was not significantly changed by any intervention. Total urinary and fecal excretion of catabolites accounted for <5% of each of the administered doses. CONCLUSIONS:Differential catabolism of the intravenous d6-α-tocopherol and oral d3-α-tocopherol doses shows both liver and intestine have roles in α-tocopherol catabolism. During the 40% fat intervention, >90% of urinary d3-α-CEHC excretion was estimated to be liver-derived, whereas during fasting <50% was from the liver with the remainder from the intestine, suggesting that there was increased intestinal α-tocopherol catabolism while d3-α-tocopherol was retained in the intestine in the absence of adequate fat/food for α-tocopherol absorption.This trial was registered at clinicaltrials.gov as NCT00862433.
3,3'-Diindolylmethane (DIM), a major phytochemical derived from ingestion of cruciferous vegetables, is also a dietary supplement. In preclinical models, DIM is an effective cancer chemopreventive agent and has been studied in a number of clinical trials. Previous pharmacokinetic studies in preclinical and clinical models have not reported DIM metabolites in plasma or urine after oral dosing, and the pharmacological actions of DIM on target tissues is assumed to be solely via the parent compound. Seven subjects (6 males and 1 female) ranging from 26-65 years of age, on a cruciferous vegetable-restricted diet prior to and during the study, took 2 BioResponse DIM 150-mg capsules (45.3 mg DIM/capsule) every evening for one week with a final dose the morning of the first blood draw. A complete time course was performed with plasma and urine collected over 48 hours and analyzed by UPLC-MS/MS. In addition to parent DIM, two monohydroxylated metabolites and 1 dihydroxylated metabolite, along with their sulfate and glucuronide conjugates, were present in both plasma and urine. Results reported here are indicative of significant phase 1 and phase 2 metabolism and differ from previous pharmacokinetic studies in rodents and humans, which reported only parent DIM present after oral administration. 3-((1H-indole-3-yl)methyl)indolin-2-one, identified as one of the monohydroxylated products, exhibited greater potency and efficacy as an aryl hydrocarbon receptor agonist when tested in a xenobiotic response element-luciferase reporter assay using Hepa1 cells. In addition to competitive phytochemical-drug adverse reactions, additional metabolites may exhibit pharmacological activity highlighting the importance of further characterization of DIM metabolism in humans. SIGNIFICANCE STATEMENT: 3,3'-Diindolylmethane (DIM), derived from indole-3-carbinol in cruciferous vegetables, is an effective cancer chemopreventive agent in preclinical models and a popular dietary supplement currently in clinical trials. Pharmacokinetic studies to date have found little or no metabolites of DIM in plasma or urine. In marked contrast, we demonstrate rapid appearance of mono- and dihydroxylated metabolites in human plasma and urine as well as their sulfate and glucuronide conjugates. The 3-((1H-indole-3-yl)methyl)indolin-2-one metabolite exhibited significant aryl hydrocarbon receptor agonist activity, emphasizing the need for further characterization of the pharmacological properties of DIM metabolites.
ScopeThe polyphenol xanthohumol (XN) improves dysfunctional glucose and lipid metabolism in diet‐induced obesity animal models. Because XN changes intestinal microbiota composition, the study hypothesizes that XN requires the microbiota to mediate its benefits.Methods and ResultsTo test the hypothesis, the study feeds conventional and germ‐free male Swiss Webster mice either a low‐fat diet (LFD, 10% fat derived calories), a high‐fat diet (HFD, 60% fat derived calories), or a high‐fat diet supplemented with XN at 60 mg kg−1body weight per day (HXN) for 10 weeks, and measure parameters of glucose and lipid metabolism. In conventional mice, the study discovers XN supplementation decreases plasma insulin concentrations and improves Homeostatic Model Assessment of Insulin Resistance (HOMA‐IR). In germ‐free mice, XN supplementation fails to improve these outcomes. Fecal sample 16S rRNA gene sequencing analysis suggests XN supplementation changes microbial composition and dramatically alters the predicted functional capacity of the intestinal microbiota. Furthermore, the intestinal microbiota metabolizes XN into bioactive compounds, including dihydroxanthohumol (DXN), an anti‐obesogenic compound with improved bioavailability.ConclusionXN requires the intestinal microbiota to mediate its benefits, which involves complex diet‐host‐microbiota interactions with changes in both microbial composition and functional capacity. The study results warrant future metagenomic studies which will provide insight into complex microbe‐microbe interactions and diet‐host‐microbiota interactions.
Extracts of red clover (Trifolium pratense L.), containing estrogenic isoflavones like genistein and daidzein and the proestrogenic isoflavones formononetin and biochanin A, are used by women as dietary supplements for the management of menopausal symptoms. Although marketed as a safer alternative to hormone therapy, red clover isoflavones have been reported to inhibit some cytochrome P450 (CYP) enzymes involved in drug metabolism. To evaluate the potential for clinically relevant drug-red clover interactions, we tested a standardized red clover dietary supplement (120 mg isoflavones per day) for interactions with the pharmacokinetics of four FDA-approved drugs (caffeine, tolbutamide, dextromethorphan, and alprazolam) as probe substrates for the enzymes CYP1A2, CYP2C9, CYP2D6, and CYP3A4/5, respectively. Fifteen peri- and postmenopausal women completed pharmacokinetic studies at baseline and 2 weeks after consuming red clover. The averaged pharmacokinetic profiles of probe substrates in serum showed no significant alterations and no changes in the areas under the curve (AUC) over 96 h. Subgroup analysis based on the demographic characteristics (BMI, menopausal status, race, and age) also showed no differences in AUC for each probe substrate. Analysis of red clover isoflavones in serum showed primarily conjugated metabolites that explain, at least in part, the red clover pharmacokinetic safety profile.