Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

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Short-Term Microbiota Manipulation and Forearm Substrate Metabolism in Obese Men : A Randomized, Double-Blind, Placebo-Controlled Trial
Reijnders, Dorien ; Goossens, Gijs H. ; Hermes, Gerben D.A. ; Smidt, Hauke ; Zoetendal, Erwin G. ; Blaak, Ellen E. - \ 2018
Obesity Facts (2018). - ISSN 1662-4025 - p. 318 - 326.

Objective: To investigate the impact of gut microbiota manipulation on fasting and postprandial skeletal muscle metabolism in humans. Methods: 40 obese, insulin-resistant males were randomized to amoxicillin (broad-spectrum antibiotic), vancomycin (narrow-spectrum antibiotic), or placebo (7 days, 1,500 mg/day). Before and after treatment, forearm blood flow and metabolite fluxes across forearm muscle were measured under fasting and postprandial (high-fat mixed-meal) conditions. Results: Vancomycin decreased bacterial diversity, reduced the abundance of Gram-positive Firmicutes, and increased the abundance of Gram-negative Proteobacteria, whereas amoxicillin did not affect microbial composition. Neither vancomycin nor amoxicillin treatment affected fasting and postprandial plasma glucose, free fatty acid (FFA), triacylglycerol (TAG), glycerol, lactate, and insulin concentrations or forearm blood flow. Fasting and postprandial net forearm muscle glucose uptake and the release of lactate were not significantly altered by antibiotic treatment as compared to placebo. Finally, antibiotic treatment did not change fasting and postprandial glycerol, FFA, and TAG fluxes across forearm muscle. Conclusion: The present study demonstrates that short-term antibiotic treatment has no effects on fasting and postprandial forearm substrate metabolism and blood flow in obese men with impaired glucose metabolism. These data suggest that short-term strategies targeting the gut microbiota to improve metabolic health may not be effective in obese humans.

Molecular relatedness of ESBL/AmpC-producing Escherichia coli from humans, animals, food and the enviroment : a pooled analysis
Dorado-Garcia, Alejandro ; Smid, J.H. ; Pelt, Wilfrid Van; Bonten, M.J.M. ; Fluit, A.C. ; Bunt, Gerrita van den; Wagenaar, J.A. ; Hordijk, J. ; Dierikx, C.M. ; Veldman, K.T. ; Koeijer, A.A. de; Dohmen, W. ; Schmitt, H. ; Liakopoulos, A. ; Pacholewicz, Ewa ; Lam, T.J.G.M. ; Velthuis, Annet ; Heuvelink, A. ; Gonggrijp, Maaike ; Duijkeren, E. van; Hoek, A.H.A.M. van; Roda Husman, A.N. de; Blaak, H. ; Havelaar, A.H. ; Mevius, D.J. ; Heederik, D.J.J. - \ 2018
Journal of Antimicrobial Chemotherapy 73 (2018)2. - ISSN 0305-7453 - p. 339 - 347.
Background: In recent years, ESBL/AmpC-producing Escherichia coli ESBL/AmpC-EC) have been isolated with increasing frequency from animals, food, environmental sources and humans. With incomplete and scattered evidence, the contribution to the human carriage burden from these reservoirs remains unclear.
Objectives: To quantify molecular similarities between different reservoirs as a first step towards risk attribution.
Methods: Pooled data on ESBL/AmpC-EC isolates were recovered from 35 studies in the Netherlands comprising.27 000 samples, mostly obtained between 2005 and 2015. Frequency distributions of ESBL/AmpC genes from 5808 isolates and replicons of ESBL/AmpC-carrying plasmids from 812 isolates were compared across 22 reservoirs through proportional similarity indices (PSIs) and principal component analyses (PCAs).
Results: Predominant ESBL/AmpC genes were identified in each reservoir. PCAs and PSIs revealed close human–animal ESBL/AmpC gene similarity between human farming communities and their animals (broilers and pigs) (PSIs from 0.8 to 0.9). Isolates from people in the general population had higher similarities to those from human clinical settings, surface and sewage water and wild birds (0.7–0.8), while similarities to livestock or food reservoirs were lower (0.3–0.6). Based on rarefaction curves, people in the general population had more diversity in ESBL/AmpC genes and plasmid replicon types than those in other reservoirs.
Conclusions: Our ‘One Health’ approach provides an integrated evaluation of the molecular relatedness of ESBL/AmpC-EC from numerous sources. The analysis showed distinguishable ESBL/AmpC-EC transmission cycles in different hosts and failed to demonstrate a close epidemiological linkage of ESBL/AmpC genes and plasmid replicon types between livestock farms and people in the general population.
Samenvatting ESBL-Attributieanalyse (ESBLAT) : Op zoek naar de bronnen van antibioticaresistentie bij de mens
Mevius, Dik ; Heederik, Dick ; Duijkeren, Engeline ; Veldman, Kees ; Essen, Alieda van; Kant, Arie ; Liakopoulos, Apostolos ; Geurts, Yvon ; Pelt, Wilfrid van; Mughini Gras, Lapo ; Schmitt, Heike ; Dierikx, Cindy ; Hoek, Angela van; Evers, Eric ; Roda Husman, Annemaria de; Blaak, Hetty ; Dissel, Jaap van; Smid, Joost ; Dohmen, Wietske ; Dorado-Garcia, Alejandro ; Havelaar, Arie ; Hordijk, Joost ; Wagenaar, Jaap ; Fluit, Ad ; Bunt, Gerrita van den; Bonten, Marc ; Velthuis, Annet ; Heuvelink, Annet ; Buter, Rianne ; Gonggrijp, Maaike ; Santman-Berends, Inge ; Lam, Theo ; Urlings, Bert ; Heres, Lourens ; Bouwknecht, Martijn ; Groot, Jacques de - \ 2018
Netherlands : De Stichting TKI Agri&Food (TKI) - 11 p.
Rapport ESBL-Attributieanalyse (ESBLAT) : Op zoek naar de bronnen van antibioticaresistentie bij de mens
Mevius, Dik ; Heederik, Dick ; Duijkeren, Engeline ; Veldman, Kees ; Essen, Alieda van; Kant, Arie ; Liakopoulos, Apostolos ; Geurts, Yvon ; Pelt, Wilfrid van; Mughini Gras, Lapo ; Schmitt, Heike ; Dierikx, Cindy ; Hoek, Angela van; Evers, Eric ; Roda Husman, Annemaria de; Blaak, Hetty ; Dissel, Jaap van; Smid, Joost ; Dohmen, Wietske ; Dorado-Garcia, Alejandro ; Havelaar, Arie ; Hordijk, Joost ; Wagenaar, Jaap ; Fluit, Ad ; Bunt, Gerrita van den; Bonten, Marc ; Velthuis, Annet ; Heuvelink, Annet ; Buter, Rianne ; Gonggrijp, Maaike ; Santman-Berends, Inge ; Lam, Theo ; Urlings, Bert ; Heres, Lourens ; Bouwknecht, Martijn ; Groot, Jacques de - \ 2018
Netherlands : De Stichting TKI Agri&Food (TKI) - 73
Improvement of Insulin Sensitivity after Lean Donor Feces in Metabolic Syndrome Is Driven by Baseline Intestinal Microbiota Composition
Kootte, Ruud S. ; Levin, Evgeni ; Salojärvi, Jarkko ; Smits, Loek P. ; Hartstra, Annick V. ; Udayappan, Shanti D. ; Hermes, Gerben ; Bouter, Kristien E. ; Koopen, Annefleur M. ; Holst, Jens J. ; Knop, Filip K. ; Blaak, Ellen E. ; Zhao, Jing Hua ; Smidt, Hauke ; Harms, Amy C. ; Hankemeijer, Thomas ; Bergman, Jacques J.G.H.M. ; Romijn, Hans A. ; Schaap, Frank G. ; Olde Damink, Steven W.M. ; Ackermans, Mariette T. ; Dallinga-Thie, Geesje M. ; Zoetendal, Erwin ; Vos, Willem M. de; Serlie, Mireille J. ; Stroes, Erik S.G. ; Groen, Albert K. ; Nieuwdorp, Max - \ 2017
Cell Metabolism 26 (2017)4. - ISSN 1550-4131 - p. 611 - 619.e6.
fecal microbiota transplantation - insulin sensitivity - intestinal microbiota composition - plasma metabolites

The intestinal microbiota has been implicated in insulin resistance, although evidence regarding causality in humans is scarce. We therefore studied the effect of lean donor (allogenic) versus own (autologous) fecal microbiota transplantation (FMT) to male recipients with the metabolic syndrome. Whereas we did not observe metabolic changes at 18 weeks after FMT, insulin sensitivity at 6 weeks after allogenic FMT was significantly improved, accompanied by altered microbiota composition. We also observed changes in plasma metabolites such as γ-aminobutyric acid and show that metabolic response upon allogenic FMT (defined as improved insulin sensitivity 6 weeks after FMT) is dependent on decreased fecal microbial diversity at baseline. In conclusion, the beneficial effects of lean donor FMT on glucose metabolism are associated with changes in intestinal microbiota and plasma metabolites and can be predicted based on baseline fecal microbiota composition. Kootte et al. show that fecal microbiota transplantation from lean donors to obese patients with metabolic syndrome improves insulin sensitivity, a transient effect associated with changes in microbiota composition and fasting plasma metabolites. Baseline fecal microbiota composition in recipients predicts the response to lean donor fecal microbiota transplantation.

Bronnen van antibioticaresistentie in het milieu en mogelijke maatregelen
Schmitt, H. ; Blaak, H. ; Kemper, M. ; Passel, M. van; Hierink, F. ; Leuken, J. van; Roda Husman, A.M. de; Grinten, E. van der; Rutgers, M. ; Schijven, J. ; Man, H. de; Hoeksma, P. ; Zuidema, T. - \ 2017
Bilthoven : Rijksinstituut voor Volksgezondheid en Milieu (RIVM rapport 2017-0058) - 110 p.
Het RIVM heeft in samenwerking met andere instituten onderzocht hoeveel resistente bacteriën via afvalwater in het Nederlandse oppervlaktewater terechtkomen. Afvalwater is, naast mest, de belangrijkste bron waardoor antibioticaresistente bacteriën in het milieu belanden. In 60 tot 100% van het onderzochte afvalwater zitten bijzonder resistente micro-organismen(BMRO), zoals ESBL-producerende E. coli en carbapenemresistente Enterobacteriaceae. Daarnaast zijn resten van antibiotica in het afvalwater gevonden.
Supplementation of Diet With Galacto-oligosaccharides Increases Bifidobacteria, but Not Insulin Sensitivity, in Obese Prediabetic Individuals
Canfora, Emanuel E. ; Beek, Christina M. van der; Hermes, Gerben D.A. ; Goossens, Gijs H. ; Jocken, Johan W.E. ; Holst, Jens J. ; Eijk, Hans M. van; Venema, Koen ; Smidt, Hauke ; Zoetendal, Erwin G. ; Dejong, Cornelis H.C. ; Lenaerts, Kaatje ; Blaak, Ellen E. - \ 2017
Gastroenterology 153 (2017)1. - ISSN 0016-5085 - p. 87 - 97.
Metabolic Control - Microbial Obesity - Prebiotics - Short-Chain Fatty Acids

Background & Aims: The gut microbiota affects host lipid and glucose metabolism, satiety, and chronic low-grade inflammation to contribute to obesity and type 2 diabetes. Fermentation end products, in particular the short-chain fatty acid (SCFA) acetate, are believed to be involved in these processes. We investigated the long-term effects of supplementation with galacto-oligosaccharides (GOS), an acetogenic fiber, on the composition of the human gut microbiota and human metabolism. Methods: We performed a double-blinded, placebo-controlled, parallel intervention study of 44 overweight or obese (body mass index, 28-40 kg/m2) prediabetic men and women (ages, 45-70 y) from October 2014 through October 2015 in Maastricht, The Netherlands. The participants were assigned randomly to groups who ingested 15 g GOS or isocaloric placebo (maltodextrin) daily with their regular meals for 12 weeks. Before and after this period, we collected data on peripheral and adipose tissue insulin sensitivity, fecal microbiota composition, plasma and fecal SCFA, energy expenditure and substrate oxidation, body composition, and hormonal and inflammatory responses. The primary outcome was the effect of GOS on peripheral insulin sensitivity, measured by the hyperinsulinemic-euglycemic clamp method. Results: Supplementation of diets with GOS, but not placebo, increased the abundance of Bifidobacterium species in feces by 5-fold (P = .009; q = 0.144). Microbial richness or diversity in fecal samples were not affected. We did not observe any differences in fecal or fasting plasma SCFA concentrations or in systemic concentrations of gut-derived hormones, incretins, lipopolysaccharide-binding protein, or other markers of inflammation. In addition, no significant alterations in peripheral and adipose tissue insulin sensitivity, body composition, and energy and substrate metabolism were found. Conclusions: Twelve-week supplementation of GOS selectively increased fecal Bifidobacterium species abundance, but this did not produce significant changes in insulin sensitivity or related substrate and energy metabolism in overweight or obese prediabetic men and women. ClincialTrials.gov number, NCT02271776.

Diet-induced weight loss decreases adipose tissue oxygen tension with parallel changes in adipose tissue phenotype and insulin sensitivity in overweight humans
Vink, R.G. ; Roumans, N.J. ; Čajlaković, M. ; Cleutjens, J.P.M. ; Boekschoten, M.V. ; Fazelzadeh, P. ; Vogel, M.A.A. ; Blaak, E.E. ; Mariman, E.C. ; Baak, M.A. van; Goossens, G.H. - \ 2017
International Journal of Obesity 41 (2017)5. - ISSN 0307-0565 - p. 722 - 728.

Background/objectives: Although adipose tissue (AT) hypoxia is present in rodent models of obesity, evidence for this in humans is limited. Here, we investigated the effects of diet-induced weight loss (WL) on abdominal subcutaneous AT oxygen tension (pO 2), AT blood flow (ATBF), AT capillary density, AT morphology and transcriptome, systemic inflammatory markers and insulin sensitivity in humans. Subjects/methods: Fifteen overweight and obese individuals underwent a dietary intervention (DI), consisting of a 5-week very-low-calorie diet (VLCD, 500 kcal day -1; WL), and a subsequent 4-week weight stable diet (WS). Body composition, AT pO 2 (optochemical monitoring), ATBF (133 Xe washout), and whole-body insulin sensitivity were determined, and AT biopsies were collected at baseline, end of WL (week 5) and end of WS (week 9). Result: Body weight, body fat percentage and adipocyte size decreased significantly during the DI period. The DI markedly decreased AT pO 2 and improved insulin sensitivity, but did not alter ATBF. Finally, the DI increased AT gene expression of pathways related to mitochondrial biogenesis and non-mitochondrial oxygen consumption. Conclusions: VLCD-induced WL markedly decreases abdominal subcutaneous AT pO 2, which is paralleled by a reduction in adipocyte size, increased AT gene expression of mitochondrial biogenesis markers and non-mitochondrial oxygen consumption pathways, and improved whole-body insulin sensitivity in humans.

Effects of Gut Microbiota Manipulation by Antibiotics on Host Metabolism in Obese Humans: a Randomized Double-blind Placebo-controlled Trial
Reijnders, Dorien ; Goossens, Gijs H. ; Neis, Evelien P.J.G. ; Beek, Christina M. van der; Most, Jasper ; Holst, Jens J. ; Lenaerts, Kaatje ; Kootte, Ruud S. ; Nieuwdorp, Max ; Groen, Albert K. ; Boekschoten, Mark ; Hermes, Gerben ; Smidt, Hauke ; Zoetendal, Erwin ; Dejong, Cornelis H.C. ; Blaak, Ellen E. - \ 2016
Homo sapiens - GSE76003 - PRJNA305937
The gut microbiota has been implicated in obesity and cardiometabolic diseases, although evidence in humans is scarce. We investigated how gut microbiota manipulation by antibiotics (7-day administration of amoxicillin, vancomycin, or placebo) affects host metabolism in 57 obese, prediabetic men. Vancomycin, but not amoxicillin, decreased bacterial diversity and reduced Firmicutes involved in short-chain fatty acid and bile acid metabolism, concomitant with altered plasma and/or fecal metabolite concentrations. Adipose tissue gene expression of oxidative pathways was upregulated by antibiotics, whereas immune-related pathways were downregulated by vancomycin. Antibiotics did not affect tissue-specific insulin sensitivity, energy/substrate metabolism, postprandial hormones and metabolites, systemic inflammation, gut permeability, and adipocyte size. Importantly, energy harvest, adipocyte size, and whole-body insulin sensitivity were not altered at 8-week follow-up, despite a still considerably altered microbial composition, indicating that interference with adult microbiota by 7-day antibiotic treatment has no clinically relevant impact on metabolic health in obese humans.
Effects of Gut Microbiota Manipulation by Antibiotics on Host Metabolism in Obese Humans : A Randomized Double-Blind Placebo-Controlled Trial
Reijnders, Dorien ; Goossens, Gijs H. ; Hermes, Gerben D.A. ; Neis, Evelien P.J.G. ; Beek, Christina M. van der; Most, Jasper ; Holst, Jens J. ; Lenaerts, Kaatje ; Kootte, Ruud S. ; Nieuwdorp, Max ; Groen, Albert K. ; Olde Damink, Steven W.M. ; Boekschoten, Mark V. ; Smidt, Hauke ; Zoetendal, Erwin G. ; Dejong, Cornelis H.C. ; Blaak, Ellen E. - \ 2016
Cell Metabolism 24 (2016)1. - ISSN 1550-4131 - p. 63 - 74.

The gut microbiota has been implicated in obesity and cardiometabolic diseases, although evidence in humans is scarce. We investigated how gut microbiota manipulation by antibiotics (7-day administration of amoxicillin, vancomycin, or placebo) affects host metabolism in 57 obese, prediabetic men. Vancomycin, but not amoxicillin, decreased bacterial diversity and reduced Firmicutes involved in short-chain fatty acid and bile acid metabolism, concomitant with altered plasma and/or fecal metabolite concentrations. Adipose tissue gene expression of oxidative pathways was upregulated by antibiotics, whereas immune-related pathways were downregulated by vancomycin. Antibiotics did not affect tissue-specific insulin sensitivity, energy/substrate metabolism, postprandial hormones and metabolites, systemic inflammation, gut permeability, and adipocyte size. Importantly, energy harvest, adipocyte size, and whole-body insulin sensitivity were not altered at 8-week follow-up, despite a still considerably altered microbial composition, indicating that interference with adult microbiota by 7-day antibiotic treatment has no clinically relevant impact on metabolic health in obese humans.

Verwerking van mestoverschot: overleven de ziekteverwekkers?
Hoeksma, P. ; Rutjes, S. ; Aarnink, A.J.A. ; Blaak, Hetty ; Buisonjé, F.E. de - \ 2016
H2O : tijdschrift voor watervoorziening en afvalwaterbehandeling 49 (2016)5. - ISSN 0166-8439 - p. 34 - 35.
mestverwerking - mestoverschotten - dierlijke meststoffen - lozing - waterverontreiniging - pathogenen - manure treatment - manure surpluses - animal manures - disposal - water pollution - pathogens
Dierlijke mest bevat ziekteverwekkende bacteriën en virussen. Worden deze gedood bij de verschillende mestverwerkingsmethodes? Die vraag wordt belangrijker nu een deel van de mestoverschotten verwerkt moet worden, waarmee en mesttransport en mestverwerkingsactiviteiten toenemen. Wageningen UR en het RIVM deden een verkennend onderzoek.
Quantifying potential sources of surface water contamination with Campylobacter jejuni and Campylobacter coli
Mughini-Gras, Lapo ; Penny, Christian ; Ragimbeau, Catherine ; Schets, Franciska M. ; Blaak, Hetty ; Duim, Birgitta ; Wagenaar, Jaap A. ; Boer, Albert de; Cauchie, Henry-Michel ; Mossong, Joel ; Pelt, Wilfrid Van - \ 2016
Water Research 101 (2016). - ISSN 0043-1354 - p. 36 - 45.
campylobacter - surface water - water quality - pollution - water pollution - microbiology - wild birds - poultry - campylobacter jejuni - campylobacter coli - netherlands - luxembourg - oppervlaktewater - waterkwaliteit - verontreiniging - waterverontreiniging - microbiologie - wilde vogels - pluimvee - nederland - luxemburg
Campylobacter is the most common causative agent of human bacterial gastroenteritis and is frequently found in surface water, where it indicates recent contamination with animal faeces, sewage effluent, and agricultural run-off. The contribution of different animal reservoirs to surface water contamination with Campylobacter is largely unknown. In the Netherlands, the massive poultry culling to control the 2003 avian influenza epidemic coincided with a 44–50% reduction in human campylobacteriosis cases in the culling areas, suggesting substantial environment-mediated spread of poultry-borne Campylobacter. We inferred the origin of surface water Campylobacter jejuni and Campylobacter coli strains in Luxembourg and the Netherlands, as defined by multilocus sequence typing, by comparison to strains from poultry, pigs, ruminants, and wild birds, using the asymmetric island model for source attribution. Most Luxembourgish water strains were attributed to wild birds (61.0%), followed by poultry (18.8%), ruminants (15.9%), and pigs (4.3%); whereas the Dutch water strains were mainly attributed to poultry (51.7%), wild birds (37.3%), ruminants (9.8%), and pigs (1.2%). Attributions varied over seasons and surface water types, and geographical variation in the relative contribution of poultry correlated with the magnitude of poultry production at either the national or provincial level, suggesting that environmental dissemination of Campylobacter from poultry farms and slaughterhouses can be substantial in poultry-rich regions.
Angiopoietin-Like Protein 4 and Postprandial Skeletal Muscle Lipid Metabolism in Overweight and Obese Prediabetics
Kolk, Birgitta W. van der; Goossens, Gijs H. ; Jocken, Johan W. ; Kersten, Sander ; Blaak, Ellen E. - \ 2016
Journal of Clinical Endocrinology and Metabolism 101 (2016)6. - ISSN 0021-972X - p. 2332 - 2339.
Context: Angiopoietin-like protein 4 (ANGPTL4) decreases plasma triacylglycerol (TAG) clearance by inhibiting lipoprotein lipase (LPL) and may contribute to impairments in lipid metabolism under compromised metabolic conditions. Objectives: To investigate the effects of a high-saturated fatty acid (SFA) mixed meal on plasma ANGPTL4 concentrations in relation to in vivo muscle LPL activity, to study the effects of dietary fat quality, and to examine skeletal muscle ANGPTL4 release. Design, Participants, Setting, and Interventions: We used a dual stable-isotope tracer technique in combination with measurements of arteriovenous concentration differences across forearm muscle to investigate muscle ANGPTL4 secretion and fatty acid handling under fasting conditions and after a high-SFA mixed meal in 73 overweight and obese humans at the Metabolic Research Unit of Maastricht University. The effect of dietary fat quality manipulation on plasma ANGPTL4 was investigated in 10 obese insulin-resistant participants. Results: The high-SFA meal decreased circulating ANGPTL4 concentrations (fasting, 5.2 ng/mL; vs 4 hours postprandial, 4.0 ng/mL; P < .001). Furthermore, skeletal muscle ANGPTL4 secretion into the circulation was observed (AUC0–4 h, P = .048). However, no association was observed between plasma ANGPTL4 and skeletal muscle very low-density lipoprotein or dietary (chylomicron) TAG extraction (AUC0–4 h, P = .372 and P = .139, respectively). In contrast to a high-SFA or high-monounsaturated fat meal, plasma ANGPTL4 remained unchanged after a high-polyunsaturated fat meal. Conclusions: ANGPTL4 is secreted by human forearm muscle in postprandial conditions after a high-SFA meal. Plasma ANGPTL4 concentrations were not associated with in vivo skeletal muscle LPL activity after a high-SFA meal. Dietary fat quality affects plasma ANGPTL4, but it remains to be elucidated whether this influences short-term skeletal muscle lipid handling. “This human in vivo study showed ANGPTL4 secretion from forearm muscle after a high-fat meal. Plasma ANGPTL4 was not associated with muscle LPL activity, but was affected by dietary fat quality
Combined epigallocatechin-3-gallate and resveratrol supplementation for 12 wk increases mitochondrial capacity and fat oxidation, but not insulin sensitivity, in obese humans: a randomized controlled trial
Most, Jasper ; Timmers, S. ; Warnke, I. ; Jocken, J.J.W. ; Boekschoten, M.V. ; Groot, Philip de; Bendik, Igor ; Schrauwen, Patrick ; Goossens, Gijs H. ; Blaak, Ellen E. - \ 2016
American Journal of Clinical Nutrition 104 (2016)1. - ISSN 0002-9165 - p. 215 - 227.
Background: The obese insulin-resistant state is characterized by
impairments in lipid metabolism.We previously showed that 3-d supplementation
of combined epigallocatechin-3-gallate and resveratrol
(EGCG+RES) increased energy expenditure and improved the
capacity to switch from fat toward carbohydrate oxidation with
a high-fat mixed meal (HFMM) test in men.
Objective: The present study aimed to investigate the longer-term
effect of EGCG+RES supplementation on metabolic profile, mitochondrial
capacity, fat oxidation, lipolysis, and tissue-specific insulin
sensitivity.
Design: In this randomized double-blind study, 38 overweight
and obese subjects [18 men; aged 38 6 2 y; body mass index
(kg/m2): 29.7 6 0.5] received either EGCG+RES (282 and
80 mg/d, respectively) or placebo for 12 wk. Before and after the
intervention, oxidative capacity and gene expression were assessed
in skeletal muscle. Fasting and postprandial (HFMM) lipid metabolism
was assessed by using indirect calorimetry, blood sampling,
and microdialysis. Tissue-specific insulin sensitivity was assessed
by a hyperinsulinemic-euglycemic clamp with [6,6-2H2]-glucose
infusion.
Results: EGCG+RES supplementation did not affect the fasting
plasma metabolic profile. Although whole-body fat mass was not
affected, visceral adipose tissue mass tended to decrease after the
intervention compared with placebo (P-time 3 treatment = 0.09).
EGCG+RES supplementation significantly increased oxidative capacity
in permeabilized muscle fibers (P-time 3 treatment ,
0.05, P-EGCG+RES , 0.05). Moreover, EGCG+RES reduced fasting
(P-time 3 treatment = 0.03) and postprandial respiratory quotient
(P-time 3 treatment = 0.01) compared with placebo. Fasting and
postprandial fat oxidation was not significantly affected by EGCG
+RES (P-EGCG+RES = 0.46 and 0.38, respectively) but declined
after placebo (P-placebo = 0.05 and 0.03, respectively). Energy expenditure
was not altered (P-time 3 treatment = 0.96). Furthermore,
EGCG+RES supplementation attenuated the increase in plasma
triacylglycerol concentrations during the HFMM test that was observed
after placebo (P-time 3 treatment = 0.04, P-placebo =
0.01). Finally, EGCG+RES had no effect on insulin-stimulated glucose
disposal, suppression of endogenous glucose production, or
lipolysis.
Conclusion: Twelve weeks of EGCG+RES supplementation increased
mitochondrial capacity and stimulated fat oxidation compared
with placebo, but this did not translate into increased tissue-specific
insulin sensitivity in overweight and obese subjects. This trial was
registered at clinicaltrials.gov as NCT02381145. Am J Clin Nutr
doi: 10.3945/ajcn.115.122937.
Keywords: insulin sensitivity, mitochondrial capacity, obesity,
polyphenols, resveratrol
Overleving van pathogenen bij mestverwerking
Hoeksma, P. ; Rutjes, S. ; Aarnink, A.J.A. ; Blaak, H. ; Buisonjé, F.E. de - \ 2016
H2O online (2016)3 maart. - 9 p.
mestverwerking - pathogenen - omgekeerde osmose - mineralen - lozing - riolering - oppervlaktewater - waterzuivering - manure treatment - pathogens - reverse osmosis - minerals - disposal - sewerage - surface water - water treatment
In de producten van verschillende mestverwerkingsprocessen zijn de concentraties gemeten van een aantal pathogenen. De resultaten laten zien dat mechanische scheiding vrijwel geen effect heeft op het aantal pathogenen. Vergisting heeft weinig effect op virussen en grampositieve bacteriën, maar reduceert wel het aantal gramnegatieve bacteriën. Grampositieve bacteriën kunnen ook hittebehandeling tot 70°C overleven. Omgekeerde osmose, een membraantechniek die in een aantal mestverwerkingsinstallaties wordt toegepast, resulteert in een mineralenconcentraat dat als meststof wordt gebruikt en een effluent dat op het riool of oppervlaktewater wordt geloosd. Effluent na omgekeerde osmose is microbiologisch schoon, mits de integriteit van het RO-proces goed wordt bewaakt.
Role of the Environment in the Transmission of Antimicrobial Resistance to Humans: A Review
Huijbers, P.M.C. ; Blaak, H. ; Jong, M.C.M. de; Graat, E.A.M. ; Vandenbroucke-Grauls, C.M.J.E. ; Roda Husman, A.M. de - \ 2015
Environmental Science and Technology 49 (2015)20. - ISSN 0013-936X - p. 11993 - 12004.
To establish a possible role for the natural environment in the transmission of clinically relevant AMR bacteria to humans, a literature review was conducted to systematically collect and categorize evidence for human exposure to extended-spectrum ß-lactamase-producing Enterobacteriaceae, methicillin-resistant Staphylococcus aureus, and vancomycin-resistant Enterococcus spp. in the environment. In total, 239 datasets adhered to inclusion criteria. AMR bacteria were detected at exposure-relevant sites (35/38), including recreational areas, drinking water, ambient air, and shellfish, and in fresh produce (8/16). More datasets were available for environmental compartments (139/157), including wildlife, water, soil, and air/dust. Quantitative data from exposure-relevant sites (6/35) and environmental compartments (11/139) were scarce. AMR bacteria were detected in the contamination sources (66/66) wastewater and manure, and molecular data supporting their transmission from wastewater to the environment (1/66) were found. The abundance of AMR bacteria at exposure-relevant sites suggests risk for human exposure. Of publications pertaining to both environmental and human isolates, however, only one compared isolates from samples that had a clear spatial and temporal relationship, and no direct evidence was found for transmission to humans through the environment. To what extent the environment, compared to the clinical and veterinary domains, contributes to human exposure needs to be quantified. AMR bacteria in the environment, including sites relevant for human exposure, originate from contamination sources. Intervention strategies targeted at these sources could therefore limit emission of AMR bacteria to the environment
Effect van processtappen op overleving van micro-organismen bij mestverwerking
Hoeksma, P. ; Aarnink, A.J.A. ; Buisonjé, F.E. de; Rutjes, S.A. ; Blaak, H. - \ 2015
Wageningen : Wageningen UR Livestock Research (Livestock Research rapport 893) - 29
mestverwerking - micro-organismen - milieuhygiëne - dierlijke meststoffen - varkensmest - productieprocessen - manure treatment - microorganisms - environmental hygiene - animal manures - pig manure - production processes
Hoe gevarieerder de darmflora, des te beter
Olie, A. ; Blaak, E.E. ; Vos, W.M. de - \ 2015
Suiker in Perspectief 2015 (2015)juli. - p. 14 - 17.
microbiota van het spijsverteringskanaal - darmen - voeding en gezondheid - gezondheidsbevordering - voedselconsumptie - gastrointestinal microbiota - intestines - nutrition and health - health promotion - food consumption
'We zijn nog niet zo ver dat we nu al kunnen zeggen wat iemand met een bepaald microbiootprofiel van de darmen het beste kan eten, maar dit zal in de toekomst wel mogelijk zijn', zegt prof. dr. Willem de Vos. Hij doet samen met prof. dr. Ellen Blaak onderzoek om duidelijkheid te krijgen over de ideale samenstelling van microbiota zodat iemand gezond en slank wordt.
The effects of 30 days resveratrol supplementation on adipose tissue morphology and gene expression patterns in obese men
Konings, E. ; Timmers, S. ; Boekschoten, M.V. ; Goossens, G.H. ; Jocken, J.W. ; Afman, L.A. ; Müller, M.R. ; Schrauwen, P. ; Mariman, E.C. ; Blaak, E.E. - \ 2014
International Journal of Obesity 38 (2014)3. - ISSN 0307-0565 - p. 470 - 473.
insulin-resistance - glucose-tolerance - adipogenesis - metabolism - health - women - mice
Polyphenolic compounds, such as resveratrol, have recently received widespread interest because of their ability to mimic effects of calorie restriction. The objective of the present study was to gain more insight into the effects of 30 days resveratrol supplementation on adipose tissue morphology and underlying processes. Eleven healthy obese men were supplemented with placebo and resveratrol for 30 days (150¿mg per day), separated by a 4-week washout period in a double-blind randomized crossover design. A postprandial abdominal subcutaneous adipose tissue biopsy was collected to assess adipose tissue morphology and gene expression using microarray analysis. Resveratrol significantly decreased adipocyte size, with a shift toward a reduction in the proportion of large and very-large adipocytes and an increase in small adipocytes. Microarray analysis revealed downregulation of Wnt and Notch signaling pathways and upregulation of pathways involved in cell cycle regulation after resveratrol supplementation, suggesting enhanced adipogenesis. Furthermore, lysosomal/phagosomal pathway and transcription factor EB were upregulated reflecting an alternative pathway of lipid breakdown by autophagy. Further research is necessary to investigate whether resveratrol improves adipose tissue function.
Impact of oral vancomycin on gut microbiota, bile acid metabolism, and insulin sensitivity
Vrieze, A. ; Out, C. ; Fuentes Enriquez de Salamanca, S. ; Jonker, L. ; Reuling, I. ; Kootte, R.S. ; Nood, E. van; Holleman, F. ; Knaapen, M. ; Romijn, J.A. ; Soeters, M.R. ; Blaak, E.E. ; Dallinga-Thie, G.M. ; Reijnders, D. ; Ackermans, M.T. ; Serlie, M.J. ; Knop, F.K. ; Holst, J.J. ; Ley, C.V. ; Kema, I.P. ; Zoetendal, E.G. ; Vos, W.M. de; Hoekstra, J.B. ; Stroes, E.S. ; Groen, A.K. ; Nieuwdorp, M. - \ 2014
Journal of Hepatology 60 (2014)4. - ISSN 0168-8278 - p. 824 - 831.
salt hydrolase activity - diet-induced obesity - intestinal microbiota - energy-expenditure - mice - resistance - adiposity - glucagon - capacity - humans
BACKGROUND: Obesity has been associated with changes in the composition and function of the intestinal microbiota. Modulation of the microbiota by antibiotics also alters bile acid and glucose metabolism in mice. Hence, we hypothesized that short term administration of oral antibiotics in humans would affect fecal microbiota composition and subsequently bile acid and glucose metabolism. METHODS: In this single blinded randomized controlled trial, 20 male obese subjects with metabolic syndrome were randomized to 7 days of amoxicillin 500mg t.i.d. or 7 days of vancomycin 500mg t.i.d. At baseline and after 1 week of therapy, fecal microbiota composition (Human Intestinal Tract Chip phylogenetic microarray), fecal and plasma bile acid concentrations as well as insulin sensitivity (hyperinsulinemic euglycemic clamp using [6,6-2H2]-glucose tracer) were measured. RESULTS: Vancomycin reduced fecal microbial diversity with a decrease of gram-positive bacteria (mainly Firmicutes) and a compensatory increase in gram-negative bacteria (mainly Proteobacteria). Concomitantly, vancomycin decreased fecal secondary bile acids with a simultaneous postprandial increase in primary bile acids in plasma (p
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