Project description:The molecular mechanisms by which dietary fruits and vegetables confer cardiometabolic benefits remain poorly understood. Historically, these beneficial properties have been attributed to the antioxidant activity of flavonoids. Here, we reveal that the host metabolic benefits associated with flavonoid consumption actually hinge on gut microbial metabolism. However, flavonoids are consumed in a largely glycosylated form, rendering them poorly available for small intestinal absorption and subjecting them to microbial metabolism in the colon. We show that a single gut microbial flavonoid catabolite is sufficient to reduce diet-induced cardiometabolic disease burden in mice. Dietary supplementation with elderberry extract attenuated obesity and continuous delivery of the catabolite 4-hydroxphenylacetic acid was sufficient to reverse hepatic steatosis. Analysis of human gut metagenomes revealed that under one percent contains a flavonol catabolic pathway, underscoring the rarity of this process. Our study will impact the design of dietary and probiotic interventions to complement traditional cardiometabolic treatment strategies.
Project description:<p>Findings from recent studies suggest that the community of microbes residing in the human body is important in disease etiology; however, it remains unclear whether personal factors modulate human microbial composition. Studies based on animal models indicate that differences in composition might be attributed to sex-mediated effects. We analyzed the relationship of sex, adiposity, and dietary fiber intake with gut microbial composition using fecal samples from human subjects. We explored the associations of these factors with metrics of community composition and specific taxon abundances. We found that men and women had significantly different microbial community composition and that women had reduced abundance of a major phylum. Adiposity was associated with gut microbiome composition and specifically in women but not in men. Fiber from fruits and vegetables and fiber from beans were each associated with increased abundance of specific bacterial taxa. These findings provide initial indications that sex, adiposity, and dietary fiber might play important roles in influencing the human gut microbiome. Better understanding of these factors may have significant implications for gastrointestinal health and disease prevention.</p>
Project description:The present study aims to investigate the dose dependent effects of consuming diets enriched in flavonoid-rich and flavonoid-poor fruits and vegetables on the urine metabolome of adults who had a ≥1.5 fold increased risk of cardiovascular diseases. A single-blind, dose-dependent, parallel randomized controlled dietary intervention was conducted where volunteers (n = 126) were randomly assigned to one of three diets: high flavonoid diet, low flavonoid diet or habitual diet as a control for 18 weeks. High resolution LC–MS untargeted metabolomics with minimal sample cleanup was performed using an Orbitrap mass spectrometer. Putative biomarkers which characterize diets with high and low flavonoid content were selected by state-of-the-art data analysis strategies and identified by HR-MS and HR-MS/MS assays. Discrimination between diets was observed by application of two linear mixed models: one including a diet-time interaction effect and the second containing only a time effect. Valerolactones, phenolic acids and their derivatives were among sixteen biomarkers related to the high flavonoid dietary exposure. Four biomarkers related to the low flavonoid diet belonged to the family of phenolic acids. For the first time abscisic acid glucuronide was reported as a biomarker after a dietary intake, however its origins have to be examined by future hypothesis driven experiments using a more targeted approach. This metabolomic analysis has identified a number of dose dependent urinary biomarkers (i.e. proline betaine or iberin-N-acetyl cysteine), which can be used in future observation and intervention studies to assess flavonoids and non-flavonoid phenolic intakes and compliance to fruit and vegetable intervention.
Project description:19 men were split into two groups. 10 were provided with a diet of twice the recommended daily intake of protein and 9 were provided meals with the recommended dietary intake of protein. Faecal samples were collected after 10 weeks on the diet. This project looked at determining any qualitative differences present in the self-proteins from each group.
Project description:The type and the amount of dietary fat have a significant influence on the metabolic pathways involved in the development of obesity, metabolic syndrome, diabetes type 2 and cardiovascular diseases. However, it is unknown to what extent this modulation is achieved through DNA methylation. We assessed the effects of cholesterol intake, the proportion of energy intake derived from fat, the ratio of polyunsaturated fatty acids (PUFA) to saturated fatty acids (SFA), the ratio of monounsaturated fatty acids (MUFA) to SFA, and the ratio of (MUFA+PUFA) to SFA on genome-wide DNA methylation patterns in normal-weight and obese children. We determined the genome-wide methylation profile in blood of 69 Greek preadolescents (~10 y old), as well as their dietary intake for two consecutive weekdays and one weekend day. The methylation levels of four sites and a CpG island were significantly correlated with total fat intake. The methylation levels of 13 islands and 16 sites were significantly correlated with PUFA/SFA; of 35 islands and 158 sites with MUFA/SFA; and of 50 islands and 130 sites with (MUFA+PUFA)/SFA. We found significant gene enrichment in 26 pathways for PUFA/SFA, including the leptin pathway, and a significant enrichment in three pathways for (MUFA+PUFA)/SFA. Our results suggest that the quality, and to a lesser extent the quantity of fat intake, influences DNA methylation, including genes involved in metabolism. Thus, specific changes in DNA methylation may play an important role in the mechanisms involved in the physiological responses to different types of dietary fat.
Project description:CYP monooxygenase-mediated conversion of LA to EpOMEs plays critical roles in the health effects of dietary LA, implicating a unique mechanistic linkage between dietary fatty acid intake and cancer risks.
Project description:The type and the amount of dietary fat have a significant influence on the metabolic pathways involved in the development of obesity, metabolic syndrome, diabetes type 2 and cardiovascular diseases. However, it is unknown to what extent this modulation is achieved through DNA methylation. We assessed the effects of cholesterol intake, the proportion of energy intake derived from fat, the ratio of polyunsaturated fatty acids (PUFA) to saturated fatty acids (SFA), the ratio of monounsaturated fatty acids (MUFA) to SFA, and the ratio of (MUFA+PUFA) to SFA on genome-wide DNA methylation patterns in normal-weight and obese children. We determined the genome-wide methylation profile in blood of 69 Greek preadolescents (~10 y old), as well as their dietary intake for two consecutive weekdays and one weekend day. The methylation levels of four sites and a CpG island were significantly correlated with total fat intake. The methylation levels of 13 islands and 16 sites were significantly correlated with PUFA/SFA; of 35 islands and 158 sites with MUFA/SFA; and of 50 islands and 130 sites with (MUFA+PUFA)/SFA. We found significant gene enrichment in 26 pathways for PUFA/SFA, including the leptin pathway, and a significant enrichment in three pathways for (MUFA+PUFA)/SFA. Our results suggest that the quality, and to a lesser extent the quantity of fat intake, influences DNA methylation, including genes involved in metabolism. Thus, specific changes in DNA methylation may play an important role in the mechanisms involved in the physiological responses to different types of dietary fat. Bisulphite converted DNA from 22 boys were hybridised to the Illumina Infinium 27k Human Methylation Beadchip v1.2.Both obese and normal-weight indiviudals were included.
Project description:Even though the importance of adequate zinc intake has been known for around half a century, a reliable diagnostic tool to assess the dietary zinc status of individual humans or populations is in absence. The specific aim of this study was to examine differential expression of specific gene transcripts that occur when the dietary intake of zinc is acutely reduced below the dietary requirement for a period of ten days. Gene expression profiles of whole blood collected before and after dietary zinc restriction were determined by microarray analyses. The data provide potential signature genes of suboptimal zinc consumption and relevant bioinformatic interpretation indicate immune response and cell cycle regulation as biological processes associated with the zinc-responsive genes.