11 research outputs found

    Impact of proanthocyanidin-rich apple intake on gut microbiota composition and polyphenol metabolomic activity in healthy mildly hypercholesterolemic subjects

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    AbstractApples are a rich source of polyphenols and fiber. Proanthocyanidins (PAs), the largest polyphenolic class in apples, can reach the colon almost intact where they interact with the gut microbiota producing simple phenolic acids. These metabolites have the potential to modulate gut microbiota composition and activity and impact on host physiology. A randomized, controlled, crossover, dietary intervention study was performed to determine the broad effects of whole apple intake on fecal gut microbiota composition and activity. Forty heathy mildly hypercholesterolemic volunteers (23 women, 17 men), with a mean BMI (± SD) 25.3 ± 3.7 kg/m2 and age 51 ± 11 years, consumed 2 apples/day (Renetta Canada, rich in PAs), or a sugar matched control apple beverage, for 8 weeks separated by a 4-week washout period in a random order. Fecal and 24-h urine samples were collected before and after each treatment. The broad effects of apple intake on fecal gut microbiota composition were explored by the high throughput sequencing (HTS) of 16S rRNA gene lllumina MiSeq sequencing (V3-V4 region). Sequencing data analysis was performed using the Quantitative Insight Into Microbial Ecology (QIIME) open-source pipeline version 1.9.1. Specific bacterial groups were also enumerated using the quantitative Fluorescence In Situ Hybridization (FISH). Furthermore, the potential formation of microbial polyphenol metabolites, after apple intake, was explored in urine using Liquid Chromatography (LC) High-Resolution Mass Spectrometry (HRMS) metabolomics. Preliminary analysis showed no changes in gut microbiota abundances measured by Illumina MiSeq, after correction for multiple testing. Apple intake significantly decreased Enterobacteriaceae population (P = 0.04) compared to the control beverage, as determined with FISH. Twenty-four polyphenol microbial metabolites were identified in higher concentrations in the apple group (P < 0.05) compared to the control, including valerolactones, valeric and phenolic acids. In conclusion, preliminary data suggest that the daily intake of 2 Renetta Canada apples significantly decreased Enterobacteriaceae population, a family known for its pathogenic members, in healthy mildly hypercholesterolemic subjects. Moreover, several polyphenol microbial metabolites were identified, suggesting that microbial activity is crucial and a prerequisite for the absorption of apple polyphenols, producing active metabolites with potential health benefits

    Mercury in the marine environment of the Canadian Arctic: Review of recent findings

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    AbstractThis review summarizes data and information which have been generated on mercury (Hg) in the marine environment of the Canadian Arctic since the previous Canadian Arctic Contaminants Assessment Report (CACAR) was released in 2003. Much new information has been collected on Hg concentrations in marine water, snow and ice in the Canadian Arctic. The first measurements of methylation rates in Arctic seawater indicate that the water column is an important site for Hg methylation. Arctic marine waters were also found to be a substantial source of gaseous Hg to the atmosphere during the ice-free season. High Hg concentrations have been found in marine snow as a result of deposition following atmospheric mercury depletion events, although much of this Hg is photoreduced and re-emitted back to the atmosphere. The most extensive sampling of marine sediments in the Canadian Arctic was carried out in Hudson Bay where sediment total Hg (THg) concentrations were low compared with other marine regions in the circumpolar Arctic. Mass balance models have been developed to provide quantitative estimates of THg fluxes into and out of the Arctic Ocean and Hudson Bay.Several recent studies on Hg biomagnification have improved our understanding of trophic transfer of Hg through marine food webs. Over the past several decades, Hg concentrations have increased in some marine biota, while other populations showed no temporal change. Marine biota also exhibited considerable geographic variation in Hg concentrations with ringed seals, beluga and polar bears from the Beaufort Sea region having higher Hg concentrations compared with other parts of the Canadian Arctic. The drivers of these variable patterns of Hg bioaccumulation, both regionally and temporally, within the Canadian Arctic remain unclear. Further research is needed to identify the underlying processes including the interplay between biogeochemical and food web processes and climate change

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    Development of a Technology-Assisted Food Frequency Questionnaire for Elementary and Middle School Children: Findings from a Pilot Study

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    Background: This pilot study collected preliminary data for the modification of the VioScreen Food Frequency Questionnaire (FFQ), an adult-validated, self-administered, web-based dietary assessment tool for use in older children. Methods: A convenience sample of 55 children, aged 6&#8722;14 years, completed the VioScreen FFQ and 3-day diet record (reference standard). Caregivers completed a short sociodemographic questionnaire. Reported dietary intakes from the VioScreen FFQ and 3-day diet record were calculated using standard nutrient databases, and descriptive statistics were used to examine differences in food/beverage items and portion sizes between the two methods. Informal focus groups obtained user feedback and identified components of the VioScreen FFQ that required modifications. Results: The highest de-attenuated Pearson correlation coefficients between the VioScreen FFQ and 3-day diet record were observed for iron (r = 0.69), saturated fat (r = 0.59), and vegetables (r = 0.56), and the lowest were for whole grains (r = 0.11) and vitamin C (r = 0.16). Qualitative feedback was overall positive, and six technological modifications were identified. Conclusion: Findings from this pilot study provided valuable information on the process of evaluating the use of the VioScreen FFQ among older children, and will inform the future development of a modified version for this population

    Can 2 Apples a Day Decrease CVD Risk and Modulate the Gut Microbiome in Mildly Hypercholesterolaemic Subjects?

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    Apples are a rich source of polyphenols and fiber. An important proportion of these bioactive components escape digestion in the upper intestinal tract and reach the colon where they can be transformed by the gut microbiota. A randomized, controlled, crossover, intervention was performed (AVAG-AGER study) to test the hypothesis that 2 apples a day can beneficially modulate the gut microbiome and cardiovascular health in mild hypercholesterolaemic subjects. Forty volunteers consumed 2 apples (Renetta Canada variety) or 100 ml of a sugar matched control drink, daily for 8 weeks separated by 4-week washout period. Blood, urine and faecal samples were collected before and after each treatment. We combined targeted and untargeted analytical strategies for metabolomic fingerprinting of body fluids.LC-HRMS Orbitrap was used for untargeted assays to identify the putative biomarkers of intake and for the validation of apple consumption markers. Additionally, targeted assay with use of UHPLC-MS/MS was employed for bile acids and carnitines quantitative profiling with isotopic dilution method. Changes in faecal populations were identified using fluorescence in situ hybridization (FISH) and 16S rRNA gene profiling Results show a significant diet interaction for total cholesterol (P=0.04) and a trend for vascular cell adhesion molecule-1 (VCAM-1) (P=0.076), providing experimental evidence of the positive role of a regular consumption of fresh apple in the diet of mild hypercholesterolaemic subjects. Metabolomics analysis allowed to further investigate the compliance and the putative mechanisms of actions, with the identification of a number of dose dependent biomarkers – including various microbial classes of apple polyphenols, as well as significant changes of bile acids in plasma of treated volunteers. FISH and 16S rRNA analysis indicates a small change in selected bacterial groups for the same group of subjects. Consuming 2 apples a day may in conclusion beneficially affect cardiovascular health and modulate both microbial composition and metabolic output
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