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Joris P.J.,Maastricht University | Joris P.J.,Top Institute of Food and Nutrition TIFN | Mensink R.P.,Maastricht University | Mensink R.P.,Top Institute of Food and Nutrition TIFN
Nutrients | Year: 2015

The effects of fat-soluble vitamin supplementation on cardiovascular disease (CVD) risk are not clear. Therefore, we performed a meta-analysis to quantify effects of fat-soluble vitamin supplements on fasting flow-mediated vasodilation (FMD) of the brachial artery, a validated marker to assess CVD risk. Randomized placebo-controlled trials (RCTs) were identified by a systematic search till July 2014. Seven RCTs studying the effects of vitamin E supplements (range: 300 to 1800 IU per day) and nine RCTs examining the effects of vitamin D supplements, that involved, respectively, 303 and 658 adults, were included. No studies with carotenoid or vitamin K supplements were found. Vitamin E supplementation increased FMD vs. control by 2.42% (95% CI: 0.46% to 4.37%; p = 0.015). No effects of vitamin D supplementation were found (0.15%; 95% CI: -0.21% to 0.51%; p = 0.41). These effects did not depend on subject characteristics, treatment characteristics or technical aspects of the FMD measurement. However, no dose-response relationship was evident for vitamin E, statistical significance depended on one study, while the levels of supplement were far above recommended intakes. The current meta-analysis, therefore, does not provide unambiguous evidence to support the use of fat-soluble vitamin supplements to improve fasting FMD in adults. © 2015 by the authors; licensee MDPI, Basel, Switzerland.


Van Der Made S.M.,Maastricht University | Van Der Made S.M.,Top Institute of Food and Nutrition TIFN | Plat J.,Maastricht University | Mensink R.P.,Maastricht University | Mensink R.P.,Top Institute of Food and Nutrition TIFN
PLoS ONE | Year: 2015

Background: In vitro and animal studies have shown positive effects of resveratrol on lipid and lipoprotein metabolism, but human studies specifically designed to examine these effects are lacking. Objective: The primary outcome parameter of this study in overweight and slightly obese subjects was the effect of resveratrol on apoA-I concentrations. Secondary outcome parameters were effects on other markers of lipid and lipoprotein metabolism, glucose metabolism, and markers for inflammation and endothelial function. Design: This randomized, placebo-controlled crossover study was conducted in 45 overweight and slightly obese men (n = 25) and women (n = 20) with a mean age of 61 ± 7 years. Subjects received in random order resveratrol (150 mg per day) or placebo capsules for 4 weeks, separated by a 4-week wash-out period. Fasting blood samples were collected at baseline and at the end of each intervention period. Results: Compliance was excellent as indicated by capsule count and changes in resveratrol and dihydroresveratrol concentrations. No difference between resveratrol and placebo was found in any of the fasting serum or plasma metabolic risk markers (mean ± SD for differences between day 28 values of resveratrol vs. placebo: apoA-I; 0.00 ± 0.12 g/L (P = 0.791), apoB100; -0.01 ± 0.11 g/L (P = 0.545), HDL cholesterol; 0.00 ± 0.09 mmol/L (P = 0.721), LDL cholesterol -0.03 ± 0.57 mmol/L (P = 0.718), triacylglycerol; 0.10 ± 0.54 mmol/L (P = 0.687), glucose; -0.08 ± 0.28 mmol/L (P = 0.064), insulin; -0.3 ± 2.5 mU/L (P = 0.516)). Also, no effects on plasma markers for inflammation and endothelial function were observed. No adverse events related to resveratrol intake were observed. Conclusion: 150 mg of daily resveratrol intake for 4 weeks does not change metabolic risk markers related to cardiovascular health in overweight and slightly obese men and women. Effects on glucose metabolism warrant further study. © 2015 van der Made et al.


Vrolix R.,NUTRIM School for Nutrition | Vrolix R.,Top Institute of Food and Nutrition TIFN | Mensink R.P.,NUTRIM School for Nutrition | Mensink R.P.,Top Institute of Food and Nutrition TIFN
Contemporary Clinical Trials | Year: 2010

Background: Many studies on the health effects of the glycemic index (GI) are confounded by differences in the intakes of other macronutrients and fibre. Little data exist about the within- and between-subject variability of the GI. Objective: Our objectives were therefore (i) to calculate the GI of eight commonly used food products with similar macronutrient and fibre composition, but with different sources of carbohydrates, (ii) to examine the inter- and intra-individual variability of the incremental area under the curve (iAUC) after consuming the reference solution, and (iii) to compare the effect of three different methods on 2-h postprandial blood glucose responses. Design: Four groups of 10 healthy subjects consumed in random order the increased (iGI) and decreased GI (dGI) variants and twice a glucose solution. All products consisted of 25 g available carbohydrates (CHO). For the fruit drink, glucose values were simultaneously analyzed using venous and capillary blood samples, and by using a continuous glucose monitoring system (CGMS). Results: The GIs for increased and decreased variants were (mean ± standard error of the mean (SEM)) 69 ± 15 and 40 ± 4 for bread, 86 ± 14 and 48 ± 8 for a fruit drink, 51 ± 12 and 20 ± 4 for cake, and 63 ± 17 and 37 ± 10 for a cookie. The inter- and intra-individual coefficient of variation (CV) of the iAUCs of the reference solution was large and varied respectively between 13 and 38%, and between 33 and 80%. Conclusions: These data suggest that the GI is difficult to use at the individual level. © 2009 Elsevier Inc. All rights reserved.


Aguirre M.,Top Institute of Food and Nutrition TIFN | Aguirre M.,Maastricht University | Aguirre M.,Applied Scientific Research | Ramiro-Garcia J.,Top Institute of Food and Nutrition TIFN | And 4 more authors.
Journal of Microbiological Methods | Year: 2014

This study investigated the stability and the activity of the microbiota from a single and a pool of donors in the TNO in vitro model of the colon (TIM-2 system). Our findings demonstrate the suitability of the preparation of a pool of fecal sample to be used for fermentation experiments. © 2014 Elsevier B.V.


Hayrapetyan H.,Wageningen University | Hayrapetyan H.,Top Institute of Food and Nutrition TIFN | Abee T.,Wageningen University | Abee T.,Top Institute of Food and Nutrition TIFN | And 2 more authors.
Food Control | Year: 2016

Environmental conditions and growth history can affect the sporulation process as well as subsequent properties of formed spores. The sporulation dynamics was studied in wet and air-dried biofilms formed on stainless steel (SS) and polystyrene (PS) for Bacillus cereus ATCC 10987 and the undomesticated food isolate B. cereus NIZO 4080. After harvesting and maturation, the wet heat resistance of spores obtained from these biofilms was tested and compared to planktonic and agar plate-derived spores. Drying/air exposure of the preformed 24 h old biofilms accelerated spore formation for both strains and resulted in higher final spore percentages. Prolonged dry incubation of more than three days triggered germination of spores in the biofilms of ATCC 10987. Spores harvested from wet biofilms on SS displayed the highest heat resistance compared to liquid, agar plate and PS biofilm derived spores. The D95 °C values for these spores were 17 and 22 min for NIZO 4080 and ATCC 10987, respectively, which was 2 and 1.2 fold higher compared to planktonic spores of these strains. Spores obtained from dried biofilms of ATCC 10987 displayed reduced heat resistance compared to wet biofilm spores. The results indicate that environmental conditions encountered by biofilms affect sporulation dynamics and spore heat resistance, thus affecting subsequent quality issues and safety risks related to these biofilms. © 2015 Elsevier Ltd.


Hayrapetyan H.,Wageningen University | Hayrapetyan H.,Top Institute of Food and Nutrition TIFN | Muller L.,Wageningen University | Tempelaars M.,Wageningen University | And 5 more authors.
International Journal of Food Microbiology | Year: 2015

Biofilm formation of Bacillus cereus reference strains ATCC 14579 and ATCC 10987 and 21 undomesticated food isolates was studied on polystyrene and stainless steel as contact surfaces. For all strains, the biofilm forming capacity was significantly enhanced when in contact with stainless steel (SS) as a surface as compared to polystyrene (PS). For a selection of strains, the total CFU and spore counts in biofilms were determined and showed a good correlation between CFU counts and total biomass of these biofilms. Sporulation was favoured in the biofilm over the planktonic state. To substantiate whether iron availability could affect B. cereus biofilm formation, the free iron availability was varied in BHI by either the addition of FeCl3 or by depletion of iron with the scavenger 2,2-Bipyridine. Addition of iron resulted in increased air-liquid interface biofilm on polystyrene but not on SS for strain ATCC 10987, while the presence of Bipyridine reduced biofilm formation for both materials. Biofilm formation was restored when excess FeCl3 was added in combination with the scavenger. Further validation of the iron effect for all 23 strains in microtiter plate showed that fourteen strains (including ATCC10987) formed a biofilm on PS. For eight of these strains biofilm formation was enhanced in the presence of added iron and for eleven strains it was reduced when free iron was scavenged. Our results show that stainless steel as a contact material provides more favourable conditions for B. cereus biofilm formation and maturation compared to polystyrene. This effect could possibly be linked to iron availability as we show that free iron availability affects B. cereus biofilm formation. © 2015 Elsevier B.V.


Joris P.J.,Maastricht University | Joris P.J.,Top Institute of Food and Nutrition TIFN | Mensink R.P.,Maastricht University | Mensink R.P.,Top Institute of Food and Nutrition TIFN
Atherosclerosis | Year: 2013

Background: Through effects on nitric oxide (NO) bioavailability, endothelial function is improved after the intake of beetroot juice-which is rich in inorganic nitrate-, but decreased after the intake of a meal. Objective: The objective of this study was to examine if beetroot juice could counteract the impairment of endothelial function associated with the ingestion of a mixed meal. Methods: Twenty healthy overweight and slightly obese men with a BMI between 28 and 35kg/m2 received in random order a mixed meal providing 56.6g of fat with beetroot juice or a control drink. The beetroot juice (140mL) provided approximately 500mg dietary nitrate. Flow-mediated dilation (FMD) of the brachial artery was measured before and 2h after meal consumption. Blood was sampled at regular intervals. Results: Postprandial changes in serum triacylglycerol (TAG) ( P=0.69), plasma glucose ( P=0.84) and insulin ( P=0.67) concentrations were comparable between the meals. After consumption of beetroot juice, the postprandial impairment in FMD following a standardized mixed meal was improved ( P=0.030) compared with the control drink (-0.37±2.92% versus-1.56±2.90%). Following beetroot juice consumption, plasma concentrations of the circulating NO pool were higher at T60, T120, and T240 ( P<0.001 at all time points). Conclusion: In healthy overweight and slightly obese men a single dose of beetroot juice attenuates the postprandial impairment of FMD following a mixed meal, possibly through increases in plasma NO concentrations. © 2013 Elsevier Ireland Ltd.


Joris P.J.,Maastricht University | Joris P.J.,Top Institute of Food and Nutrition TIFN | Zeegers M.P.,Maastricht University | Mensink R.P.,Maastricht University | Mensink R.P.,Top Institute of Food and Nutrition TIFN
Atherosclerosis | Year: 2015

Background: Obesity is associated with vascular endothelial dysfunction. Effects of weight loss on endothelial function are however not clear. Therefore, we performed a meta-analysis to quantify effects of weight loss on flow-mediated vasodilation (FMD) of the brachial artery, a measurement of endothelial function. Methods: Studies with experimental (RCTs) and quasi-experimental designs published before June 2014 were identified by a systematic search. Changes in FMD were defined as the difference between measurements before and after the study. For RCTs, changes were corrected for those in the no-weight loss control group. Summary estimates of weighted mean differences (WMDs) in FMD and 95% confidence intervals (CIs) were calculated using random-effect meta-analyses. The impact of subject characteristics, type of weight-loss treatment, and dietary composition on changes in FMD was also investigated. Results: Four RCTs involving 265 subjects were included. Weight loss increased FMD vs. control by 3.29% (95% CI: 0.98-5.59%; P=0.005; mean weight loss: 8.6kg). A total of 1517 subjects participated in 33 studies with 49 relevant study arms. It was estimated that each 10kg decrease in body weight increased fasting FMD by 1.11% (95% CI: 0.47-1.76%; P=0.001). Effects were more pronounced when participants had coexisting obesity-related morbidities. Also, effects may be larger when subjects received low-fat diets or weight-reduction regimens including exercise therapy or weight-loss medication. Conclusion: Weight loss significantly improves fasting FMD in adults, which is a risk marker for cardiovascular disease. Effects may depend on subject characteristics, type of weight-loss treatment, and dietary composition. © 2014 Elsevier Ireland Ltd.


PubMed | Wageningen University and Top Institute of Food and Nutrition TIFN
Type: Journal Article | Journal: PloS one | Year: 2015

Sigma 54 is a transcriptional regulator predicted to play a role in physical interaction of bacteria with their environment, including virulence and biofilm formation. In order to study the role of Sigma 54 in Bacillus cereus, a comparative transcriptome and phenotypic study was performed using B. cereus ATCC 14579 WT, a markerless rpoN deletion mutant, and its complemented strain. The mutant was impaired in many different cellular functions including low temperature and anaerobic growth, carbohydrate metabolism, sporulation and toxin production. Additionally, the mutant showed lack of motility and biofilm formation at air-liquid interphase, and this correlated with absence of flagella, as flagella staining showed only WT and complemented strain to be highly flagellated. Comparative transcriptome analysis of cells harvested at selected time points during growth in aerated and static conditions in BHI revealed large differences in gene expression associated with loss of phenotypes, including significant down regulation of genes in the mutant encoding enzymes involved in degradation of branched chain amino acids, carbohydrate transport and metabolism, flagella synthesis and virulence factors. Our study provides evidence for a pleiotropic role of Sigma 54 in B. cereus supporting its adaptive response and survival in a range of conditions and environments.


PubMed | Wageningen University and Top Institute of Food and Nutrition TIFN
Type: | Journal: International journal of food microbiology | Year: 2015

Biofilm formation of Bacillus cereus reference strains ATCC 14579 and ATCC 10987 and 21 undomesticated food isolates was studied on polystyrene and stainless steel as contact surfaces. For all strains, the biofilm forming capacity was significantly enhanced when in contact with stainless steel (SS) as a surface as compared to polystyrene (PS). For a selection of strains, the total CFU and spore counts in biofilms were determined and showed a good correlation between CFU counts and total biomass of these biofilms. Sporulation was favoured in the biofilm over the planktonic state. To substantiate whether iron availability could affect B. cereus biofilm formation, the free iron availability was varied in BHI by either the addition of FeCl3 or by depletion of iron with the scavenger 2,2-Bipyridine. Addition of iron resulted in increased air-liquid interface biofilm on polystyrene but not on SS for strain ATCC 10987, while the presence of Bipyridine reduced biofilm formation for both materials. Biofilm formation was restored when excess FeCl3 was added in combination with the scavenger. Further validation of the iron effect for all 23 strains in microtiter plate showed that fourteen strains (including ATCC10987) formed a biofilm on PS. For eight of these strains biofilm formation was enhanced in the presence of added iron and for eleven strains it was reduced when free iron was scavenged. Our results show that stainless steel as a contact material provides more favourable conditions for B. cereus biofilm formation and maturation compared to polystyrene. This effect could possibly be linked to iron availability as we show that free iron availability affects B. cereus biofilm formation.

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