107 research outputs found

    In vitro bioconversion of polyphenols from black tea and red wine/grape juice by human intestinal microbiota displays strong interindividual variability

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    Dietary polyphenols in tea and wine have been associated with beneficial health effects. After ingestion, most polyphenols are metabolized by the colonic microbiota. The current study aimed at exploring the interindividual variation of gut microbial polyphenol bioconversion from 10 healthy human subjects. In vitro fecal batch fermentations simulating conditions in the distal colon were performed using polyphenols from black tea and a mixture of red wine and grape juice. Microbial bioconversion was monitored by NMR- and GC-MS-based profiling of diverse metabolites and phenolics. The complex polyphenol mixtures were degraded to a limited number of key metabolites. Each subject displayed a specific metabolite profile differing in composition and time courses as well as levels of these metabolites. Moreover, clear differences depending on the polyphenol sources were observed. In conclusion, varying metabolite pathways among individuals result in different metabolome profiles and therefore related health effects are hypothesized to differ between subjects

    Novel approaches for analysing gut microbes and dietary polyphenols: challenges and opportunities

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    Polyphenols, ubiquitously present in the food we consume, may modify the gut microbial composition and/or activity, and moreover, may be converted by the colonic microbiota to bioactive compounds that influence host health. The polyphenol content of fruit and vegetables and derived products is implicated in some of the health benefits bestowed on eating fruit and vegetables. Elucidating the mechanisms behind polyphenol metabolism is an important step in understanding their health effects. Yet, this is no trivial assignment due to the diversity encountered in both polyphenols and the gut microbial composition, which is further confounded by the interactions with the host. Only a limited number of studies have investigated the impact of dietary polyphenols on the complex human gut microbiota and these were mainly focused on single polyphenol molecules and selected bacterial populations. Our knowledge of gut microbial genes and pathways for polyphenol bioconversion and interactions is poor. Application of specific in vitro or in vivo models mimicking the human gut environment is required to analyse these diverse interactions. A particular benefit can now be gained from next-generation analytical tools such as metagenomics and metatranscriptomics allowing a wider, more holistic approach to the analysis of polyphenol metabolism. Understanding the polyphenol gut microbiota interactions and gut microbial bioconversion capacity will facilitate studies on bioavailability of polyphenols in the host, provide more insight into the health effects of polyphenols and potentially open avenues for modulation of polyphenol bioactivity for host health

    Microbial diversity in the human intestine and novel insights from metagenomics

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    Bacterial communities reside in very different ecological niches on and within the human host, such as those associated with the alimentary tract. The human gastrointestinal tract is populated with as many as 100 trillion bacterial cells, whose collective genome likely reflects the co-evolution between the microbial community and its host. Recent progress has highlighted the intriguing diversity of these bacterial populations and their important contributions to human physiology. Thus, a thorough understanding of the autochthonous component of the intestinal microbiota is expected to provide crucial information not only on how to develop therapies for various gastrointestinal diseases but also on how to choose the next generation of probiotic bacteria as part of novel functional foods. Recently, novel culture-independent approaches such as metagenomics-based techniques were shown to be crucially important for the exploration of the biodiversity of the human intestinal microbiota

    L-arabinose co-ingestion delays glucose absorption derived from sucrose in healthy men and women : A double-blind, randomized crossover trial

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    Dietary interventions to delay carbohydrate digestion or absorption can effectively prevent hyperglycaemia in the early postprandial phase. L-arabinose can specifically inhibit sucrase. It remains to be assessed whether co-ingestion of L-arabinose with sucrose delays sucrose digestion, attenuates subsequent glucose absorption and impacts hepatic glucose output. In this double-blind, randomised crossover study, we assessed blood glucose kinetics following ingestion of a 200-ml drink containing 50 g of sucrose with 7·5 g of L-arabinose (L-ARA) or without L-arabinose (CONT) in twelve young, healthy participants (24 ± 1 years; BMI: 22·2 ± 0·5 kg/m2). Plasma glucose kinetics were determined by a dual stable isotope methodology involving ingestion of (U-13C6)-glucose-enriched sucrose, and continuous intravenous infusion of (6,6–2H2)-glucose. Peak glucose concentrations reached 8·18 ± 0·29 mmol/l for CONT 30 min after ingestion. In contrast, the postprandial rise in plasma glucose was attenuated for L-ARA, because peak glucose concentrations reached 6·62 ± 0·18 mmol/l only 60 min after ingestion. The rate of exogenous glucose appearance for L-ARA was 67 and 57 % lower compared with CONT at t = 15 min and 30 min, respectively, whereas it was 214 % higher at t = 150 min, indicating a more stable absorption of exogenous glucose for L-ARA compared with CONT. Total glucose disappearance during the first hour was lower for L-ARA compared with CONT (11 ± 1 v. 17 ± 1 g, P < 0·0001). Endogenous glucose production was not differentially affected at any time point (P = 0·27). Co-ingestion of L-arabinose with sucrose delays sucrose digestion, resulting in a slower absorption of sucrose-derived glucose without causing adverse effects in young, healthy adults

    Mesenchymal-epithelial signalling in tumour microenvironment: role of high-mobility group Box 1.

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    Glucose deprivation, hypoxia and acidosis are characteristic features of the central core of most solid tumours. Myofibroblasts are stromal cells present in many such solid tumours, including those of the colon, and are known to be involved in all stages of tumour progression. HMGB1 is a nuclear protein with an important role in nucleosome stabilisation and gene transcription; it is also released from immune cells and is involved in the inflammatory process. We report that the microenvironmental condition of glucose deprivation is responsible for the active release of HMGB1 from various types of cancer cell lines (HT-29, MCF-7 and A549) under normoxic conditions. Recombinant HMGB1 (10 ng/ml) triggered proliferation in myofibroblast cells via activation of PI3K and MEK1/2. Conditioned medium collected from glucose-deprived HT-29 colon cancer cells stimulated the migration and invasion of colonic myofibroblasts, and these processes were significantly inhibited by immunoneutralising antibodies to HMGB1, RAGE and TLR4, together with specific inhibitors of PI3K and MEK1/2. Our data suggest that HMGB1 released from cancer cells under glucose deprivation is involved in stimulating colonic myofibroblast migration and invasion and that this occurs through the activation of RAGE and TLR4, resulting in the activation of the MAPK and PI3K signalling pathways. Thus, HMGB1 might be released by cancer cells in areas of low glucose in solid tumours with the resulting activation of myofibroblasts and is a potential therapeutic target to inhibit solid tumour growth

    Effect of Deutetrabenazine on Chorea Among Patients With Huntington Disease A Randomized Clinical Trial

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    Importance Deutetrabenazine is a novel molecule containing deuterium, which attenuates CYP2D6 metabolism and increases active metabolite half-lives and may therefore lead to stable systemic exposure while preserving key pharmacological activity. Objective To evaluate efficacy and safety of deutetrabenazine treatment to control chorea associated with Huntington disease. Design, Setting, and Participants Ninety ambulatory adults diagnosed with manifest Huntington disease and a baseline total maximal chorea score of 8 or higher (range, 0-28; lower score indicates less chorea) were enrolled from August 2013 to August 2014 and randomized to receive deutetrabenazine (n = 45) or placebo (n = 45) in a double-blind fashion at 34 Huntington Study Group sites. Interventions Deutetrabenazine or placebo was titrated to optimal dose level over 8 weeks and maintained for 4 weeks, followed by a 1-week washout. Main Outcomes and Measures Primary end point was the total maximal chorea score change from baseline (the average of values from the screening and day-0 visits) to maintenance therapy (the average of values from the week 9 and 12 visits) obtained by in-person visits. This study was designed to detect a 2.7-unit treatment difference in scores. The secondary end points, assessed hierarchically, were the proportion of patients who achieved treatment success on the Patient Global Impression of Change (PGIC) and on the Clinical Global Impression of Change (CGIC), the change in 36-Item Short Form– physical functioning subscale score (SF-36), and the change in the Berg Balance Test. Results Ninety patients with Huntington disease (mean age, 53.7 years; 40 women [44.4%]) were enrolled. In the deutetrabenazine group, the mean total maximal chorea scores improved from 12.1 (95% CI, 11.2-12.9) to 7.7 (95% CI, 6.5-8.9), whereas in the placebo group, scores improved from 13.2 (95% CI, 12.2-14.3) to 11.3 (95% CI, 10.0-12.5); the mean between-group difference was –2.5 units (95% CI, –3.7 to –1.3) (P < .001). Treatment success, as measured by the PGIC, occurred in 23 patients (51%) in the deutetrabenazine group vs 9 (20%) in the placebo group (P = .002). As measured by the CGIC, treatment success occurred in 19 patients (42%) in the deutetrabenazine group vs 6 (13%) in the placebo group (P = .002). In the deutetrabenazine group, the mean SF-36 physical functioning subscale scores decreased from 47.5 (95% CI, 44.3-50.8) to 47.4 (44.3-50.5), whereas in the placebo group, scores decreased from 43.2 (95% CI, 40.2-46.3) to 39.9 (95% CI, 36.2-43.6), for a treatment benefit of 4.3 (95% CI, 0.4 to 8.3) (P = .03). There was no difference between groups (mean difference of 1.0 unit; 95% CI, –0.3 to 2.3; P = .14), for improvement in the Berg Balance Test, which improved by 2.2 units (95% CI, 1.3-3.1) in the deutetrabenazine group and by 1.3 units (95% CI, 0.4-2.2) in the placebo group. Adverse event rates were similar for deutetrabenazine and placebo, including depression, anxiety, and akathisia. Conclusions and Relevance Among patients with chorea associated with Huntington disease, the use of deutetrabenazine compared with placebo resulted in improved motor signs at 12 weeks. Further research is needed to assess the clinical importance of the effect size and to determine longer-term efficacy and safety

    The global retinoblastoma outcome study : a prospective, cluster-based analysis of 4064 patients from 149 countries

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    DATA SHARING : The study data will become available online once all analyses are complete.BACKGROUND : Retinoblastoma is the most common intraocular cancer worldwide. There is some evidence to suggest that major differences exist in treatment outcomes for children with retinoblastoma from different regions, but these differences have not been assessed on a global scale. We aimed to report 3-year outcomes for children with retinoblastoma globally and to investigate factors associated with survival. METHODS : We did a prospective cluster-based analysis of treatment-naive patients with retinoblastoma who were diagnosed between Jan 1, 2017, and Dec 31, 2017, then treated and followed up for 3 years. Patients were recruited from 260 specialised treatment centres worldwide. Data were obtained from participating centres on primary and additional treatments, duration of follow-up, metastasis, eye globe salvage, and survival outcome. We analysed time to death and time to enucleation with Cox regression models. FINDINGS : The cohort included 4064 children from 149 countries. The median age at diagnosis was 23·2 months (IQR 11·0–36·5). Extraocular tumour spread (cT4 of the cTNMH classification) at diagnosis was reported in five (0·8%) of 636 children from high-income countries, 55 (5·4%) of 1027 children from upper-middle-income countries, 342 (19·7%) of 1738 children from lower-middle-income countries, and 196 (42·9%) of 457 children from low-income countries. Enucleation surgery was available for all children and intravenous chemotherapy was available for 4014 (98·8%) of 4064 children. The 3-year survival rate was 99·5% (95% CI 98·8–100·0) for children from high-income countries, 91·2% (89·5–93·0) for children from upper-middle-income countries, 80·3% (78·3–82·3) for children from lower-middle-income countries, and 57·3% (52·1-63·0) for children from low-income countries. On analysis, independent factors for worse survival were residence in low-income countries compared to high-income countries (hazard ratio 16·67; 95% CI 4·76–50·00), cT4 advanced tumour compared to cT1 (8·98; 4·44–18·18), and older age at diagnosis in children up to 3 years (1·38 per year; 1·23–1·56). For children aged 3–7 years, the mortality risk decreased slightly (p=0·0104 for the change in slope). INTERPRETATION : This study, estimated to include approximately half of all new retinoblastoma cases worldwide in 2017, shows profound inequity in survival of children depending on the national income level of their country of residence. In high-income countries, death from retinoblastoma is rare, whereas in low-income countries estimated 3-year survival is just over 50%. Although essential treatments are available in nearly all countries, early diagnosis and treatment in low-income countries are key to improving survival outcomes.The Queen Elizabeth Diamond Jubilee Trust and the Wellcome Trust.https://www.thelancet.com/journals/langlo/homeam2023Paediatrics and Child Healt

    Genomic Dissection of Bipolar Disorder and Schizophrenia, Including 28 Subphenotypes

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    publisher: Elsevier articletitle: Genomic Dissection of Bipolar Disorder and Schizophrenia, Including 28 Subphenotypes journaltitle: Cell articlelink: https://doi.org/10.1016/j.cell.2018.05.046 content_type: article copyright: © 2018 Elsevier Inc
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