Protein intake and the resulting postprandial aminoacidemia are important anabolic stimuli. However, considerable individual variation in postprandial amino acid (AA) kinetics can be expected. In this study, the aim was to quantify the variability in postprandial AA kinetics within and between individuals after consumption of a moderately digestible plant protein concentrate (lucerne (alfalfa), LPC) and an easily digestible animal protein concentrate (whey, WPC). Eighteen healthy young adults consumed a 20 g protein drink on five occasions (3xLPC; 2xWPC). Plasma AA kinetics were calculated, and a mixed model was fitted to describe within- and between-individual variability and to calculate the intra-class correlation coefficient (ICC). AA kinetics showed significant variation between and within individuals, both for WPC and LPC. Between-individual variation in postprandial response for total AA (TAA) or total essential AA (TEAA) was in general larger than within-individual variation for WPC with the ICC with or without blood volume (BV) correction ranging from 0·45 to 0·77. For LPC, the within-individual variation of the TAA response was higher than the between-individual variation, and for TEAA they were more or less equal, with the ICC with or without BV correction ranging from 0·34 to 0·58 for LPC. Subjects with a high level of aminoacidemia for one protein source were not necessarily those with a high level for the other protein source. Our results indicate that between- and within-person variation in postprandial AA kinetics are substantial and should not be neglected.

ETHNOPHARMACOLOGICAL RELEVANCE:Bitter gourd (Momordica charantia L.) is known for its ability to reduce parameters of diabetes, but its effects on prediabetic subjects have been scarcely studied. AIM OF THE STUDY:To assess the efficacy of Momordica charantia supplementation in a prediabetic population on markers of glucose homeostasis. METHODS:Two randomized controlled studies were conducted to assess the effect of bitter gourd supplementation in a prediabetic population. Study 1 was a 4-week cross-over intervention trial (n = 30), with freeze-dried bitter gourd (BG) fruit juice (2.4 g/day) or a cucumber-based control product (CC). Study 2 was a parallel trial (n = 38) lasting 12 weeks, with freeze-dried whole fruits (3.6 g/day) or a cucumber-based matched control supplement. Effects on fasting plasma glucose (FPG), insulin, HbA1c, fructosamine, postprandial glucose after an oral glucose tolerance test, and several safety biomarkers were also analyzed in both trials before and after the interventions. RESULTS:In Study 1, no significant differences were found between the bitter gourd and placebo interventions. However, a reduction in FPG in subjects with higher baseline values were found following bitter gourd supplementation, which was not observed in the control group. However, in Study 2, we observed significant reductions of FPG (p = 0.014), fasting insulin (p = 0.007), and HOMA-IR (p = 0.003) after a 12-week intervention with the bitter gourd supplement. In addition, between treatment analysis resulted in significant effects on FPG levels (p = 0.026) and HOMA-IR (p = 0.045) with no significant effects on other biomarkers related to glucose metabolism. On average, bitter gourd intervention reduced FPG by ∼0.05 mmol/L per week, whereas FPG remained unchanged following placebo. In both studies, there were no indications of health risks or side effects from consumption of the supplements. CONCLUSION:Results suggest that supplementation with bitter gourd fruit can have positive effects on fasting plasma glucose and insulin among prediabetic subjects when provided over an extended period of at least 12 weeks.

Nowadays, a healthier and more sustainable lifestyle is the subject of much research. One example is the use of crossover trials to investigate the uptake of proteins, usually from alternatives to animal-based sources, by healthy volunteers. The data analysis is complex and requires many decisions on the part of the scientists involved. Such a process can be streamlined and made more objective and reproducible through bespoke software. This paper describes such a software package, aaresponse , for the environment, available as open source. It features ample visualization functions, supports consistent curation strategies, and compares amino acid uptake of different protein meals (interventions) through the use of mixed models analysing parameters of interest like the area under the curve (AUC). The defining feature is the use of parametric curves to fit the amino acid levels over time, increasing the robustness of the approach and allowing for more strict quality control strategies.

The endocannabinoid system (ECS) is dysregulated during obesity and metabolic disorders. Weight loss favours the re-establishment of ECS homeostatic conditions, but also the fatty acid composition of the diet can modulate endocannabinoid profiles. However, the combined impact of nutrient quality and energy restriction on the ECS remains unclear. In this 12 weeks randomized controlled trial, men and women (40-70 years) with obesity (BMI: 31.3 +/- 3.5 kg/ m(2)) followed either a low nutrient quality 25% energy-restricted (ER) diet (n=39) high in saturated fats and fructose, or a high nutrient quality ER diet (n=34) amongst others enriched in n-3 polyunsaturated fatty acids (PUFAs) or kept their habitual diet (controls). Profiles of plasma- and adipose N-acylethanolamines and mono-acyl glycerol esters were quantified using LC-MS/MS. Gene expression of ECS-related enzymes and receptors was determined in adipose tissue. Measurements were performed under fasting conditions before and after 12 weeks. Our results showed that plasma level of the DHA-derived compound docosahexaenoylethanolamide (DHEA) was decreased in the low nutrient quality ER diet (P<0.001) compared with the high nutrient quality ER diet, whereas anandamide (AEA) and arachidonoylglycerol (2-AG) levels were unaltered. However, adipose tissue gene expression of the 2-AG synthesizing enzyme diacylglycerol lipase alpha (DAGL-alpha) was increased following the low nutrient quality ER diet (P<.009) and differed upon intervention with both other diets. Concluding, nutrient quality of the diet affects N-acylethanolamine profiles and gene expression of ECS-related enzymes and receptors even under conditions of high energy restriction in abdominally obese humans. ClinicalTrials.gov NCT02194504 (c) 2024 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY license ( http://creativecommons.org/licenses/by/4.0/ )

Pea protein is an interesting alternative for animal-based proteins due to its good availability, low cost, and relatively balanced amino acid (AA) profile. Its digestibility may be affected by heat treatment and food texture. Our aim was to study in vivo AA absorption kinetics and gastric behavior of pea protein products differing in heat treatment and texture and compare this with in vitro digestion. We included fourteen males in this randomized crossover trial with three iso-caloric and iso-volumetric treatments: a 420-mL heated drink, 420-mL unheated drink and 105-g heated gel (semi-solid) consumed with 315 mL water, all containing 20 g pea protein. Gastric MRI scans were made until 90 min post-prandial. Blood samples were collected at baseline and up to 5 h. All treatments were tested with an in vitro digestion model (INFOGEST). Heat treatment did not alter AA absorption kinetics and gastric emptying. Time to maximum peak was delayed for the gel treatment (total AAs: 66.9 versus 48.0 min for both drinks, essential AAs: 75.4 versus 50.0 and 46.6 min for the drinks). For the gel treatment initial emptying was faster due to the rapid passage of water. In vitro, the degree of hydrolysis was highest for the unheated drink in the gastric phase and for the gel treatment in the intestinal phase. In conclusion, heat treating pea protein products does not affect digestion. In contrast, texture of pea protein products can be altered to influence the rate of gastric emptying and AA absorption without affecting total AA absorption.

Kori-tofu is a frozen soy tofu, and soy consumption is associated with positive effects on cardiometabolic health markers. We aimed to assess the potential of Kori-tofu to improve cardiometabolic health outcomes in humans by repetitive daily consumption. In a double-blind randomized controlled cross-over trial, 45 subjects aged 40-70 years with (mildly) elevated cholesterol levels, received a four week Kori-tofu intervention or whey protein control intervention with a four week wash-out period in between. Cardiometabolic biomarkers were measured before and after both interventions. A significant decrease in total, low-density lipids (LDL), and high-density lipids (HDL) cholesterol, Hemoglobin A1c (HbA1c), fructosamine and systolic blood pressure was observed within the Kori-tofu intervention. However, many of these findings were also observed in the control intervention. Only adiponectin changes were different between treatments but did not change significantly within interventions. Improvements in cardiometabolic markers within the Kori-tofu intervention point toward potential beneficial health effects. Due to the lack of significant effects as compared to control, there is, however, currently no substantiating evidence to claim that Kori-tofu has beneficial effects on cardiometabolic health.

IntroductionAn elevated postprandial glucose response is associated with an increased risk of cardiometabolic diseases. Existing research suggests large heterogeneity in the postprandial glucose responses to identical meals and food products between individuals, but the effect of other consumed meals during the day and the order of meals during the day on the heterogeneity in postprandial glucose responses still needs to be investigated. In addition, the robustness of the glucose responses to meals or foods is still unknown.ObjectivesThe overall aim of the project is to assess whether the glucose response to a meal is sufficiently person-specific to use in personalized dietary advice. We aim to answer the question: “How replicable are glucose responses to meals within individuals and how consistent is the variation in glucose responses between individuals?”MethodsThe question will be assessed under standardized conditions of a 9-week fully controlled dietary intervention in which all meals are the same between individuals and consumed in a fixed order at a fixed time. 63 apparently healthy men and women with a BMI of 25–40 kg/m2 and aged 45–75 years were enrolled in the RepEAT study (NCT05456815), of whom 53 participants completed the study. The RepEAT study comprised a fully controlled dietary intervention of nine weeks, consisting of three repetitive periods of three weeks. Within each three-week period, a variety of meals and food products were offered during breakfast, lunch, dinner and in between meal snacks. Throughout the dietary intervention, glucose was continuously monitored using Freestyle Libre Pro IQ monitors. Physical activity was monitored using the ActiGraph and ActivPAL. To measure the association between glucose responses and an individual’s phenotype, various measurements were performed before the start of the dietary intervention including an oral glucose tolerance test, a high-fat mixed meal challenge, assessment of body fat distribution including liver fat (MRI/MRS), and cardiometabolic markers.DiscussionThe repetitive and fully controlled nature of the dietary study allows detailed assessment of the replicability of the glucose responses to meals and food products within individuals. Furthermore, the consistency of the variation between individuals independent of insulin resistance will be determined.

Valorization and utilization of brewers’ spent grain (BSG) are of great interest in terms of reducing food waste and promoting more sustainable food systems. In this study, we aimed to evaluate the nutritional value of upcycled barley/rice proteins (BRP) extracted from BSG and compare this with pea proteins (PP). A randomized, cross-over, double-blind controlled trial was conducted with twelve participants (age: 24 ± 2.8 years, BMI: 23.3 ± 3.0 kg/m2). During three separate visits with a one-week washout period between visits, participants received 20 g BRP, PP, or the benchmark protein whey (WP). Blood-free amino acids (AA) were measured to determine postprandial AA uptake kinetics. The estimated total AA (TAA) uptake of BRP was 69% when compared to WP and 87% when compared to PP. The time to reach the maximum values was similar between the three protein sources. When comparing individual essential AA responses between BRP and PP, we observed higher responses in methionine and tryptophane and lower responses in lysine, histidine, and isoleucine for BRP compared to PP. This study demonstrates that BRP exhibits comparable postprandial TAA uptake profiles to PP. The findings highlight the complementarity of BRP and PP, which may offer the potential for blending approaches to optimize protein quality for overall health.

AbstractBackgroundPea protein is an interesting alternative for animal-based proteins due to its good availability, low cost and relatively balanced amino acid (AA) profile. Its digestibility may be affected by heat treatment and food texture.ObjectivesTo studyin-vivoAA absorption kinetics and gastric behavior of pea protein products differing in heat treatment and texture and compare this within-vitrodigestion.DesignFourteen males participated in a randomized crossover trial. Iso-caloric and iso-volumetric treatments were a 420-mL heated drink, 420-mL unheated drink and 105-g heated gel (semi-solid) consumed with 315 mL water, all containing 20 g pea protein. Gastric MRI scans were made until 90 minutes post-prandial. Blood samples were collected at baseline and up to five hours. All treatments were tested with anin-vitrodigestion model (INFOGEST).ResultsHeat treatment did not alter AA absorption kinetics and gastric emptying. Time to maximum peak was delayed for the gel treatment (total AAs: 66.9 versus 48.0 min for both drinks, essential AAs: 75.4 versus 50.0 and 46.6 min for the drinks). For the gel treatment initial emptying was faster due to the rapid passage of water.In-vitro, the degree of hydrolysis was highest for the unheated drink in the gastric phase and for the gel treatment in the intestinal phase.ConclusionHeat treating pea protein products does not affect digestion. In contrast, texture of pea protein products can be altered to influence the rate of gastric emptying and AA absorption without affecting total AA absorption.

Important considerations in the choice of future sustainable protein sources for human application are tolerance, nutritional quality, and potential health benefits. We evaluated, in a double-blind cross-over intervention trial, tolerance, nutritional quality, and potential health effects of two sustainable protein sources. Thirty-six apparently healthy older adults (age 62.3 ± 7.2yrs, BMI 25 ± 3 kg/m2) received 40 g/day bovine-plasma protein (BP), corn protein (CP) or, as a benchmark, whey protein (WP) for one week with a washout period of one week in-between. In 12 participants, we also determined postprandial amino acid (PAA) uptake kinetics upon consumption of 20 g BP, CP, or WP. Changes in self-reported gastrointestinal complaints and intestinal permeability assessed using a multi-sugar acetylsalicylic acid test did not differ between the interventions. Clear differences in PAA responses were observed after consumption of the different proteins, but clear essential amino acid responses were observed for all proteins. BP consumption resulted in a small but significant increase in blood pressure outcomes, and CP consumption resulted in a small but significant decrease in insulin levels when compared to the other interventions. In conclusion, alternative protein concentrates and isolates studied here can be consumed in relative high quantities without experiencing unwanted GI complaints or gut barrier dysfunction and they can be a good source of essential amino acids. The rise in blood pressure observed during the BP intervention, potentially linked to the elevated salt content of the BP, constitutes a potential health issue. Future studies with longer intervention periods might however be recommended.

A human intervention trial was conducted to study amino acid uptake of the novel Lemna protein concentrate (LPC) in comparison to whey (WPC). The study was a cross-over, double-blind, controlled trial in which 12 healthy participants received 20 grams of LPC and WPC in randomised order. The LPC consumption resulted in a significant lower postprandial increase in almost all individual amino acids, total amino acid (TAA) and total essential amino acids (TEAA) compared to WPC based on area under the curve (AUC) calculations. When the AUC after WPC consumption was set at 100%, LPC showed a relative AUC of 60.4% for TAA and 66.3% for the TEAA. Interindividual variation for LPC was high with an uptake of TEAA of LPC compared to WPC ranging from 18.2 to 94.2%. Human intervention trials can partly replace animal trials as they fully reflect the human situation and provide estimates on individual variations.

Recent studies suggest that circulating fibroblast growth factor 21 (FGF21) may be a marker of metabolic health status. We performed a secondary analysis of a 12-week randomized controlled trial to investigate the effects of two energy restriction (ER) diets on fasting and postprandial plasma FGF21 levels, as well as to explore correlations of plasma FGF21 with metabolic health markers, (macro)nutrient intake and sweet-taste preference. Abdominally obese subjects aged 40–70 years (n = 110) were randomized to one of two 25% ER diets (high-nutrient-quality diet or low-nutrient-quality diet) or a control group. Plasma FGF21 was measured in the fasting state and 120 min after a mixed meal. Both ER diets did not affect fasting or postprandial plasma FGF21 levels despite weight loss and accompanying health improvements. At baseline, the postprandial FGF21 response was inversely correlated to fasting plasma glucose (ρ = −0.24, p = 0.020) and insulin (ρ = −0.32, p = 0.001), HOMA-IR (ρ = −0.34, p = 0.001), visceral adipose tissue (ρ = −0.24, p = 0.046), and the liver enzyme aspartate aminotransferase (ρ = −0.23, p = 0.021). Diet-induced changes in these markers did not correlate to changes in plasma FGF21 levels upon intervention. Baseline higher habitual polysaccharide intake, but not mono- and disaccharide intake or sweet-taste preference, was related to lower fasting plasma FGF21 (p = 0.022). In conclusion, we found no clear evidence that fasting plasma FGF21 is a marker for metabolic health status. Circulating FGF21 dynamics in response to an acute nutritional challenge may reflect metabolic health status better than fasting levels.

Background: Despite the established relation between energy restriction (ER) and metabolic health, the most beneficial nutrient composition of a weight-loss diet is still a subject of debate. Objectives: The aim of the study was to examine the additional effects of nutrient quality on top of ER. Methods: A parallel-designed, 12-week 25% ER dietary intervention study was conducted (clinicaltrials.gov: NCT02194504). Participants aged 40-70 years with abdominal obesity were randomized over 3 groups: a 25% ER high-nutrient-quality diet (n = 40); a 25% ER low-nutrient-quality diet (n = 40); or a habitual diet (n = 30). Both ER diets were nutritionally adequate, and the high-nutrient-quality ER diet was enriched in MUFAs. n-3 PUFAs, fiber, and plant protein and reduced in fructose. Before and after the intervention, intrahepatic lipids, body fat distribution, fasting and postprandial responses to a mixed-meal shake challenge test of cardiometabolic risk factors, lipoproteins, vascular measurements, and adipose tissue transcriptome were assessed. Results: The high-nutrient-quality ER diet (-8.4 +/- 3.2) induced 2.1 kg more weight loss (P = 0.007) than the low-nutrient-quality ER diet (-6.3 +/- 3.9), reduced fasting serum total cholesterol (P = 0.014) and plasma triglycerides (P < 0.001). promoted an antiatherogenic lipoprotein profile, and induced a more pronounced decrease in adipose tissue gene expression of energy metabolism pathways than the low-quality ER diet. Explorative analyses showed that the difference in weight loss between the two ER diets was specifically present in insulin-sensitive subjects (HOMA-IR <= 2.5). in whom the high-nutrient-quality diet induced 3.9 kg more weight loss than the low-nutrient-quality diet. Conclusions: A high-nutrient-quality 25% ER diet is more beneficial for cardiometabolic health than a low-nutrient-quality 25% ER diet. Overweight, insulin-sensitive subjects may benefit more from a high-than a low-nutrient-quality ER diet with respect to weight loss, due to potential attenuation of glucose-induced lipid synthesis in adipose tissue. [GRAPHICS] .

BackgroundWe previously showed that whole-grain wheat (WGW) consumption had beneficial effects on liver fat accumulation, as compared to refined wheat (RW). The mechanisms underlying these effects remain unclear.ObjectiveIn this study, we investigated the effects of WGW vs. RW consumption on plasma metabolite levels to explore potential underlying mechanisms of the preventive effect of WGW consumption on liver fat accumulation.MethodsTargeted metabolomics of plasma obtained from a concluded 12-week double-blind, randomized controlled trial was performed. Fifty overweight or obese men and women aged 45–70 years with mildly elevated levels of plasma cholesterol were randomized to either 98 g/d of WGW or RW products. Before and after the intervention, a total of 89 fasting plasma metabolite concentrations including acylcarnitines, trimethylamine-N-oxide (TMAO), choline, betaine, bile acids, and signaling lipids were quantified by UPLC-MS/MS. Intrahepatic triglycerides (IHTG) were quantified by 1H-MRS, and multiple liver markers, including circulating levels of β-hydroxybutyrate, alanine transaminase (ALT), aspartate transaminase (AST), γ-glutamyltransferase (γ-GT), serum amyloid A (SAA), and C-reactive protein, were assessed.ResultsThe WGW intervention increased plasma concentrations of four out of 52 signaling lipids—lysophosphatidic acid C18:2, lysophosphatidylethanolamine C18:1 and C18:2, and platelet-activating factor C18:2—and decreased concentrations of the signaling lipid lysophosphatidylglycerol C20:3 as compared to RW intervention, although these results were no longer statistically significant after false discovery rate (FDR) correction. Plasma concentrations of the other metabolites that we quantified were not affected by WGW or RW intervention. Changes in the above-mentioned metabolites were not correlated to change in IHTG upon the intervention.ConclusionPlasma acylcarnitines, bile acids, and signaling lipids were not robustly affected by the WGW or RW interventions, which makes them less likely candidates to be directly involved in the mechanisms that underlie the protective effect of WGW consumption or detrimental effect of RW consumption on liver fat accumulation.Clinical trial registration[www.ClinicalTrials.gov], identifier [NCT02385149].

The growing world population will increase the demand for new sustainable foods and ingredients. Here we studied the safety and tolerance of Lemna minor, a new sustainable vegetable crop from the duckweed family. Twenty-four healthy adults consumed either L. minor plant material or spinach as vegetable (170 g fresh weight) as part of a warm meal on 11 consecutively days in a randomized controlled parallel trial design. The intervention meals had a different recipe for each day of the week. All participants had to report daily if they experienced gastric complaints, feelings of hunger, fullness, desire to eat, thirst, general health, nausea, and stool consistency. Only hunger, flatulence and constipation were significantly different between both intervention groups. At the start and end of the intervention, blood and urine were sampled in order to analyze biomarkers for general health, e.g., kidney function, liver function, cardiovascular health, inflammation and iron status. Both intervention groups did not show significant differences for these biomarkers. In taste attributes the L. minor-based products showed in only a few specific cases a significant difference compared to the spinach-based products. Based on the results we conclude that 11 consecutive days intake of 170 g fresh weight L. minor plants as a cooked vegetable does not result in any adverse effect in healthy adult subjects.

Approximately 70% of birch pollen allergic patients in Europe experience hypersensitivity reactions to Immunoglobulin E (IgE) cross-reactive food sources. This so-called pollen-food syndrome (PFS) is defined by allergic symptoms elicited promptly by the ingestion of fruits, nuts, or vegetables in these patients. So far, in the literature, less attention has been given to Bet v 1 cross-reactive symptoms caused by pear (Pyrus communis). In the Netherlands, pears are widely consumed. The primary objective of this study was to measure the type and severity of allergic symptoms during pear challenges in birch pollen allergic patients, with a positive history of pear allergy, using two different pear varieties. Fifteen patients were included, skin prick test (SPT), prick-to-prick test (PTP), specific Immunoglobulin E (sIgE), and single-blind oral challenges were performed with two pear (Pyrus communis) varieties: the ‘Cepuna’ (brand name Migo®) and the ‘Conference’ pears. All patients were sensitized to one or both pear varieties. A total of 12 out of 15 participants developed symptoms during the ‘Cepuna’ food challenge and 14/15 reacted during the ‘Conference’ challenge. Challenges with the ‘Cepuna’ pears resulted in less objective symptoms (n = 2) in comparison with challenges with ‘Conference’ pears (n = 7). Although we did not find significance between both varieties in our study, we found a high likelihood of fewer and less severe symptoms during the ‘Cepuna’ challenges. Consequently selected pear sensitized patients can try to consume small doses of the ‘Cepuna’ pear outside the birch pollen season.

The increased usage of alternative Ayurvedic treatments as potential health-beneficial therapies emphasizes the importance of studying its efficacy in sound placebo-controlled intervention trials. An example of such a traditional Ayurvedic herbal preparation is Mohana Choorna, a mixture composed of 20 different herbs and used to prevent and treat type 2-diabetes (T2D). We studied the efficacy of “Mohana Choorna” on T2D-related parameters in subjects with impaired glucose tolerance. In a double blind, placebo-controlled cross-over trial, 19 overweight (BMI > 27 kg/m2) subjects aged 50–70 years with an impaired glucose tolerance received two four-week interventions, i.e., herbal or placebo with a four-week wash-out between interventions. HbA1c, glucose, insulin, triglycerides, cholesterol, blood pressure and augmentation index were measured before and after both interventions at fasting and during a glucose tolerance test. After both interventions, urine was collected to measure treatment exposure using LCMS-based metabolomics and whole genome gene-expression in adipose tissue of 13 subjects. The herbal intervention did not affect plasma glucose triglycerides, cholesterol, blood pressure or the augmentation index but showed a trend towards an increased insulin, HOMA-IR and postprandial insulin levels (p = 0.054, p = 0.056 and p = 0.095 respectively). An increase in expression of inflammation-related gene sets in adipose tissue was observed after the herbal intervention compared to placebo. Urine metabolomic analysis did not reveal a correlation of the presence of specific plant metabolites with “health markers”. Our findings suggest that there is no substantiating evidence to claim that four weeks’ use of the Ayurvedic herbal supplement Mohana Choorna beneficially affects glucose homeostasis.