Background: Previous research has shown the efficacy of mulberry extracts for lowering post-prandial glucose (PPG) responses. The postulated mechanism is slowing of glucose absorption, but effects on glucose disposal or endogenous production are also possible. This research assessed the effect of a specified mulberry fruit extract (MFE) on these three glucose flux parameters.
View Article and Find Full Text PDFBackground: It is challenging to find an iron compound that combines good bioavailability with minimal sensory changes when added to seasonings or condiments. Ferric pyrophosphate (FePP) is currently used to fortify bouillon cubes, but its bioavailability is generally low. Previously, the addition of a stabilizer, sodium pyrophosphate (NaPP), improved iron bioavailability from a bouillon drink.
View Article and Find Full Text PDFFlavonoids are a large class of dietary molecules, among which quercetin is the most ubiquitous, which undergo an extensive intestinal phase-II metabolism. We compared the in vivo metabolism of quercetin in healthy volunteers with two in vitro models, HT29 cells and 3 D human intestinal tissues. Supernatants of the in vitro experiments and the human intestinal fluids (HIF) were analyzed by LC-IMS-MS and LC-HRMS in a qualitative way.
View Article and Find Full Text PDFObjectives: Quercetin is one of the main dietary flavonoids and undergoes a substantial intestinal phase-II metabolism. Quercetin conjugates have been detected in plasma and in urine, but their presence in the small intestine has not been assessed. This study aimed to investigate the intestinal metabolism and metabolite excretion of quercetin by the human small intestinal wall after oral dosing.
View Article and Find Full Text PDFPolyphenols, a complex group of secondary plant metabolites, including flavonoids and phenolic acids, have been studied in depth for their health-related benefits. The activity of polyphenols may, however, be hampered when consumed together with protein-rich food products, due to the interaction between polyphenols and proteins. To that end we have tested the bioavailability of representatives of a range of polyphenol classes when consumed for five days in different beverage matrices.
View Article and Find Full Text PDFFe fortification of centrally manufactured and frequently consumed condiments such as bouillon cubes could help prevent Fe deficiency in developing countries. However, Fe compounds that do not cause sensory changes in the fortified product, such as ferric pyrophosphate (FePP), exhibit low absorption in humans. Tetra sodium pyrophosphate (NaPP) can form soluble complexes with Fe, which could increase Fe bioavailability.
View Article and Find Full Text PDFObjective: Intake of plant sterol (PS)-enriched foods effectively lowers plasma total- and LDL-cholesterol concentrations while increasing plasma PS concentrations. The magnitude of this increase has not been systematically assessed. This study aimed to investigate the effect of PS-enriched foods on plasma PS concentrations by performing a meta-analysis of randomized controlled studies.
View Article and Find Full Text PDFBackground: Extracts from Hoodia gordonii have been shown to decrease food intakes and body weights in animals and were proposed as a food supplement or ingredient for weight management.
Objective: We assessed the safety and efficacy of a 15-d repeated consumption of H. gordonii purified extract (HgPE) relative to a placebo in humans.
Background: The relationship between plant sterol (PS) absorption and circulatory concentrations with cholesterol absorption and biosynthesis during PS consumption has yet to be clearly elucidated in humans. It is therefore essential to examine campesterol, β-sitosterol, and cholesterol absorption and cholesterol fractional synthesis rate (FSR) following PS consumption in individuals with high versus low basal circulatory PS concentrations.
Design: A randomized, crossover trial was conducted in 82 hypercholesterolemic men consuming spreads with or without 2 g/d of PS for two 4-week periods, each separated by a 4-week washout.
The aim of this study was to investigate whether milk reduces the bioaccessibility of tea catechins, which would compromise tea beneficial effects ascribed to polyphenols. Adding milk to black tea has been shown to lead to polyphenol-protein complexes. So far, data on the intestinal stability of polyphenol-protein complexes are scarce.
View Article and Find Full Text PDFAm J Clin Nutr
November 2010
Background: Random serial sampling is widely used in population pharmacokinetic studies and may have advantages compared with conventional fixed time-point evaluation of iron fortification.
Objective: Our objective was to validate random serial sampling to judge the efficacy of iron fortification of a low-fat margarine.
Design: We conducted a 32-wk placebo-controlled, double-blind, iron-intervention trial in 18-40-y-old Swiss women (n = 142) with serum ferritin (SF) concentrations <25 μg/L.
Dietary peptides have been suggested to possess biological activity in vivo and could affect cardiovascular disease parameters, based on data derived from in vitro experiments. Isolated peptides are often tested in in vitro cellular assays or on heterologously expressed molecular target proteins. The stimulatory or inhibitory effect on target proteins in vitro has often been used as the justification to test these compounds directly in vivo.
View Article and Find Full Text PDFSelected di- and tripeptides exhibit angiotensin-I converting enzyme (ACE) inhibitory activity in vitro. However, the efficacy in vivo is most likely limited for most peptides due to low bioavailability. The purpose of this study was to identify descriptors of intestinal stability, permeability, and ACE inhibitory activity of dipeptides.
View Article and Find Full Text PDFObjective: Optimal bone mass in early adulthood is achieved through appropriate diet and lifestyle, thereby protecting against osteoporosis and risk of bone fracture in later life. Calcium and vitamin D are essential to build adequate bones, but calcium intakes of many population groups do not meet dietary reference values. In addition, changes in dietary patterns are exacerbating the problem, thereby emphasizing the important role of calcium-rich food products.
View Article and Find Full Text PDFAn integration of metabolomics and pharmacokinetics (or nutrikinetics) is introduced as a concept to describe a human study population with different metabolic phenotypes following a nutritional intervention. The approach facilitates an unbiased analysis of the time-response of body fluid metabolites from crossover designed intervention trials without prior knowledge of the underlying metabolic pathways. The method is explained for the case of a human intervention study in which the nutrikinetic analysis of polyphenol-rich black tea consumption was performed in urine over a period of 48 h.
View Article and Find Full Text PDFIntestinal intubation studies have demonstrated that lipids induce satiety, but the contribution of lipid processing by the stomach on satiety remains poorly understood. In this explorative, randomized, placebo-controlled, crossover study we tested whether delayed lipid absorption, increased cholecystokinin (CCK), decelerated gastric emptying (GE), and increased satiety can be achieved by controlling lipid distribution in the stomach. Six healthy men were intubated nasogastrically.
View Article and Find Full Text PDFPhytosterols (plant sterols and stanols) are well known for their LDL-cholesterol (LDL-C)-lowering effect. A meta-analysis of randomized controlled trials in adults was performed to establish a continuous dose-response relationship that would allow predicting the LDL-C-lowering efficacy of different phytosterol doses. Eighty-four trials including 141 trial arms were included.
View Article and Find Full Text PDFATP-binding cassette hetero-dimeric transporters G5 and G8 (ABCG5/G8) have been postulated to mediate intestinal cholesterol efflux, whereas Niemann-Pick C1 Like 1 (NPC1L1) protein is believed to be essential for intestinal cholesterol influx. The individual or combined genetic markers, such as single nuclear polymorphisms (SNPs), of these two transporter genes may explain inter-individual variations in plasma cholesterol response following plant sterol (PS) intervention. The present study was aimed at investigating the association between ABCG5/G8 and NPC1L1 genotype SNPs with sterol absorption and corresponding plasma concentrations.
View Article and Find Full Text PDFTripeptides may possess bioactive properties. For instance, blood pressure lowering is attributed to the proline-rich tripeptides Ile-Pro-Pro (IPP), Leu-Pro-Pro (LPP), and Val-Pro-Pro (VPP). However, little is known about their absorption, distribution, and elimination characteristics.
View Article and Find Full Text PDFTransepithelial transport of the ACE inhibitory peptides Ile-Pro-Pro and Val-Pro-Pro was studied in different models of absorption. Apparent permeability (P(app)) values for absorptive transport across Caco-2 monolayers were 1.0+/-0.
View Article and Find Full Text PDFDietary supplementation with plant sterols, stanols, and their esters reduces intestinal cholesterol absorption, thus lowering plasma LDL cholesterol concentration in humans. It was suggested that these beneficial effects are attributable in part to induction of genes involved in intestinal cholesterol transport, e.g.
View Article and Find Full Text PDFDietary intake of plant sterol esters (PSE) lowers plasma LDL-cholesterol (LDL-C), but can modestly increase plasma plant sterol concentrations. The objective of the present study was to investigate the impact of increasing doses of dietary PSE on plasma and liver sterol concentrations as well as on aortic foam cell development as a marker of atherogenesis. One-hundred and twenty F(1)B hybrid Syrian golden hamsters (20 per group) were fed a basal atherogenic diet containing 30% of energy as fat and 0.
View Article and Find Full Text PDFBlood cholesterol levels are affected by diet and in particular by the type and amount of fat intake. In recent years, vegetable oil spreads containing plant sterols/stanols (as their fatty acid esters) have been developed. Numerous clinical trials on spreads with added plant sterols/stanols have shown that they have much greater cholesterol-lowering properties than conventional vegetable oil spreads.
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