This study investigated the effect of partially substituting dietary animal with plant protein (PP) sources on the fecal microbiota composition and metabolome in men with increased cardiometabolic risk. In a randomized, controlled, crossover feeding trial (NCT04236518), 19 men with high plasma triglycerides and waist circumference completed two 4-week isoenergetic diets: a flexitarian diet high in PP sources (FLEX, 64% PP) and a more animal-based control diet (CON, 36% PP). Fecal microbiota (shotgun metagenomics: taxa and metabolic pathways) and metabolome (targeted LC-MS) profiles were assessed before and after each diet and integrated with the host plasma metabolome. Delta values (Δd28-d1) were computed (n = 15 participants with all samples available), inter-individual variation was extracted to account for cross-over design, and OPLS-DA analyses comparing FLEX and CON Δd28-d1 were performed. Variables were selected based on their contribution to the diet discrimination effect (VIP > 1.5) and significant differences between groups (p-value < 0.05 from the paired Wilcoxon signed-rank test). The gut microbiota diversity remained unchanged, but FLEX reduced taxa associated with animal-based diets (e.g., Alistipes putredinis). Compared to CON, FLEX increased fecal xanthurenic acid and decreased the genetic potential for indole production. Combined with previously reported plasma changes (increased indole propionic acid and decreased indoxyl sulfate after FLEX), these findings suggest a shift away from indole production toward kynurenine and indole propionic acid-related tryptophan pathways, possibly driven by higher fiber intake, particularly from legumes. A one-month flexitarian diet thus modulated in men specific microbial taxa and metabolism, particularly tryptophan catabolism. These coordinated changes in microbial composition, functional potential, and metabolites indicate that diets higher in PP sources influence gut microbiota activities relevant to cardiometabolic health.

Tropical peas can be used as both animal feed and human food but the nutritional quality of their proteins for humans is currently poorly documented. Here, 3 varieties of tropical peas were studied at two stages of seed maturity (green or dry): Cajanus Cajan (CC), Vigna Unguiculata (VU) and Lablab Purpureus (LP). Pea seeds were prepared traditionally (soaking and cooking). The true ileal digestibility (TID) of their amino acids was measured in minipigs, and the digestible indispensable amino acid score (DIAAS) was calculated. Total amino acid TID was not significantly different between pea varieties (95.8 % for CC vs 93.0 % for VU vs 96.7 % for LP), but it decreased slightly between green and dry seeds. The DIAAS for adults of green and dry seeds was 104 and 111 for CC, 94 and 96 for VU, and 78 and 64 for LP. For human consumption, Cajanus Cajan and Vigna Unguiculata provided a good balance in indispensable amino acids in relation to adult requirements, whereas Lablab Purpureus was deficient in sulphur amino acids.

Processes are being developed to exploit proteins from the residue of rapeseed oil extraction. Two main fractions of proteins can be purified: cruciferin and napin. The present work was carried out to characterize the nutritional quality of these fractions, while exploring the effect of the extraction conditions (neutral or acid), and that of the post extraction process (heating 1 h, 120 degrees C). The true ileal digestibility (TID) of their amino acids (AA) was measured in minipigs, to calculate the digestible indispensable amino acid score (DIAAS). The TID of cruciferin was high (95 %) compared to that of napin (87 %). The extraction process and the heat treatment had no effect on the TID of napin. The DIAAS for adults was 117 % for cruciferin, and 82-89 % for napin (branched-chain AA being the limiting AA). Improving the TID of napin would enable this interesting source of cysteine and lysine to be better exploited in human nutrition.

BACKGROUND:Postprandial vascular endothelial dysfunction is an early marker of atherosclerosis. Meal protein has been reported to reduce endothelial dysfunction in adults, and the effect could be mediated by the amino acid content. OBJECTIVES:This trial aims to assess the effect of a specifically designed plant-protein blend that contains high leucine, arginine, and cysteine on postprandial endothelial function in the elderly. METHODS:In a randomized, double-blind, 3-period crossover (2-wk washout), controlled trial, we compared the vascular effects of 3 high-saturated-fat high-sucrose (HFHS) meals containing either our specific plant-protein blend, or milk protein, or without added protein. The trial was conducted on 29 healthy adults aged >65 y presenting ≥2 cardiometabolic risk factors. Postprandial vascular function was evaluated at fasting, 3 h, and 5 h postprandially, using brachial flow-mediated dilation (FMD), hand microvascular reactivity (using Flowmetry Laser Doppler, FLD), and finger reactive hyperemia index (using Peripheral Arterial Tonometry, RHI). Immune cell count and gene expression in peripheral blood mononuclear cells (PBMCs) were also assessed postprandially. Data were analyzed using mixed linear models with repeated measurements on participants for meal composition and time of sampling. This trial was registered at clinicaltrials.gov as NCT04923555. RESULTS:FMD incremental AUC value decreased after meals (time effect P < 0.01), with no significant differences between meals. RHI also decreased with time (P < 0.01). PBMC count and monocyte chemoattractant protein-1 (MCP1), IL-1β, and IL-6 expression increased after meals showing postprandial endothelial activation (P < 0.05). Overall, meal composition had no effect on any of the postprandial changes (Ps>0.10). CONCLUSIONS:In healthy adults aged >65 y presenting cardiometabolic risk, adding protein to an HFHS challenge meal does not mitigate postprandial impairments in vascular endothelial function and inflammatory activation. Further studies are needed to explore the potential differences with younger adults.

BACKGROUND & AIM:Dietary shifts replacing animal protein (AP) with plant protein (PP) sources have been associated with lowering cardiometabolic risk (CMR), but underlying mechanisms are poorly characterized. This nutritional intervention aims to characterize the metabolic changes induced by diets containing different proportions of AP and PP sources in males at CMR. DESIGN:This study is a 4-week, crossover, randomized, controlled-feeding trial in which 19 males with CMR followed two diets providing either 36 % for the control diet (CON-D) or 64 % for the flexitarian diet (FLEX-D) of total protein intake from PP sources. Plasma nontargeted metabolomes (LC-MS method) were measured in the fasted state and after a high-fat challenge meal at the end of each intervention arm. Lipogenesis and protein synthesis fluxes, flow-mediated dilatation (FMD) and gluco-lipidic responses were assessed after the challenge meal. Data were analyzed with mixed models, and univariate and multivariate models for metabolomics data. RESULTS:In both arms CMR improved with time, with decreased body weight (-0.9 %), insulin resistant (-34 %, HOMA-IR, Homeostatic Model Assessment for Insulin Resistance) and low-density lipoproteins (LDL)-cholesterol (-11 %). Diet had no effect on FMD or metabolic fluxes, but a trend (0.05 <p ≤ 0.1) was observed for a stronger decrease in HOMA-IR and lower postprandial glucose after FLEX-D vs CON-D. The abundance of 21 and 37 metabolites differed between diets at fasted and fed states, respectively, including food intake biomarkers of AP (methylhistidine, eicosapentaenoic acid, hydroxyprolines) and PP sources (trigonelline, N-acetyl-ornithine). In fasted or fed states, indole acrylic acid and indole propionic acid, both products of tryptophan catabolism, were higher after FLEX-D vs CON-D, while the indispensable amino acids-related metabolites alpha-aminoadipic acid, hydroxymethylbutyric acids and propionylcarnitine were lower. In the postprandial state only, the ω-oxidation products dodecanedioic, tetradecanedioic and hexadecanedioic acids were higher after FLEX-D vs CON-D. CONCLUSIONS:Despite little changes in risk factors after 4 wk, this study evidenced subtle metabolic adaptations in amino acids and lipid metabolism and gut microbiota activity occurring after higher PP source intake that may be beneficial to CMR. CLINICALTRIALS: GOV STUDY IDENTIFIER:NCT04236518. CLINICAL TRIAL REGISTRY:NCT04236518 on ClinicalTrials.gov.

There seems to be a consensus for a reduction in the consumption of meat products in developed countries. However, due to the specific nutritional needs of the elderly, the place of meat products in their diet requires special attention. Indeed because of its high content in bioavailable minerals such as iron and zinc, and its high content in B vitamins, meat helps to reduce dietary inadequacies in these micronutrients, and their health consequences. This is particularly the case of anemia, a significant part of which is explained by insufficient intakes of iron, vitamins B12 and B9 in the elderly. In addition, most of the epidemiological studies shows a protective effect of meat consumption against skeletal muscle loss of mass and function, because of its high content in proteins of good nutritional quality. While too high consumption of meat products may unbalance the diet reducing the share of plant products, and expose to higher risks of non-communicable diseases, regular consumption of moderate quantities of meat ensures that specific nutritional requirements are met, and prevents the development of anemia and sarcopenia in the elderly.

There is a high inter-individual variability in response to food, determined by multiple interacting factors, such as age, sex, genotype, gut microbiota, eating behaviours, physical activity or socio-demographic factors. Previous studies demonstrated the possibility to predict the postprandial glycemic response to food in healthy adults based on deep phenotyping. We hypothesize that inter-individual variability may be amplified at later ages, as a result of different life trajectories and long-life exposures. The MetabotypAGE project proposes exploring the inter-individual variability in response to food in the elderly (ClinicalTrials.gov Identifier NCT06163794). The first interdisciplinary task aimed to establish the best tools and methods to recruit a large highly diverse group of subjects including those living in rural areas, and to carry out deep phenotyping adapted to the older population living at home. The second objective of MetabotypAGE is an exploratory study on 150 healthy people aged 60 to 75, who will wear a CGM for 2 weeks, during which they will eat four standardized test meals. Their post-prandial glycemia will be followed after the test meals. Furthermore, their metabolic flexibility will be assessed with a nutritional challenge test (type PhenFlex) at the clinical center. Volunteers will be extensively phenotyped with a battery of functional tests (physical aptitude, gustatory, olfactory and masticatory function, cognition, vascular function…), analyses on plasma, PBMC, urine, feces and saliva (biochemical, transcriptomics, metagenomics, and metabolomics) and >30 questionnaires to cover many dimensions including their metabolism, physical capacity, socio-economical status, cognitive function, digestive function, and dietary habits. The volunteers will be classified in various metabotypes using clustering methods, based on the glycemic responses to test meals. Then, the multidimentional data collected will be used (i) to characterize the metabotypes (descriptive statistics) and (ii) to explore links between postprandial response to the test meals and the subjects’ descriptive data, using correlation networks based on a Gaussian Graphical Model method. The MetabotypAGE consortium combines partners with complementary skills in nutrition and health of the elderly, several clinical research structures, and local players in social action for senior citizens. Our ultimate goal is to lay solid bases for the development of tailor-made recommendations for seniors.

Background: Plant proteins (PPs) have been associated with better cardiovascular health than animal proteins (APs) in epidemiological studies. However, the underlying metabolic mechanisms remain mostly unknown.Objectives: Using a combination of cutting-edge isotopic methods, we aimed to better characterize the differences in protein and energy metabolisms induced by dietary protein sources (PP compared with AP) in a prudent or western dietary context. Methods: Male Wistar rats (n 1/4 44, 8 wk old) were fed for 4.5 mo with isoproteic diets differing in their protein isolate sources, either AP (100% milk) or PP (50%:50% pea: wheat) and being normal (NFS) or high (HFS) in sucrose (6% or 15% kcal) and saturated fat (7% or 20% kcal), respectively. We measured body weight and composition, hepatic enzyme activities and lipid content, and plasma metabolites. In the intestine, liver, adipose tissues, and skeletal muscles, we concomitantly assessed the extent of amino acid (AA) trafficking using a 15N natural abundance method, the rates of macronutrient routing to dispensable AA using a 13C natural abundance method, and the metabolic fluxes of protein synthesis (PS) and de novo lipogenesis using a 2H labeling method. Data were analyzed using ANOVA and Mixed models.Results: At the whole-body level, PP limited HFS-induced insulin resistance (-27% in HOMA-IR between HFS groups, P < 0.05). In the liver, PP induced lower lipid content (-17%, P < 0.01) and de novo lipogenesis (-24%, P < 0.05). In the different tissues studied, PP induced higher AA transamination accompanied by higher routings of dietary carbohydrates and lipids toward dispensable AA synthesis by glycolysis and beta-oxidation, resulting in similar tissue PS and protein mass.Conclusions: In growing rats, compared with AP, a balanced blend of PP similarly supports protein anabolism while better limiting whole -body and tissue metabolic dysregulations through mechanisms related to their less optimal AA profile for direct channeling to PS.

<p>Description of additional methods and procedures used in the study.</p>

We aimed to assess if casein structure affects its digestion and its subsequent amino acid delivery kinetic. Higher nitrogen levels were recovered in dialysates after in vitro digestions of sodium caseinate (SC, formed of small aggregates) compared to micellar casein (MC, native form of casein) and calcium caseinate (CC, intermediate structure). Likewise, plasma indispensable amino-acid concentration peak was higher after SC compared to MC or CC ingestion in healthy volunteers in a randomized, double blind, cross-over study. In pigs, gamma-scintigraphy using labelled meals revealed that SC was mainly localized in the proximal part of the stomach whereas MC was distributed in the whole gastric cavity. Caseins were found in both solid and liquid phases and partly hydrolyzed casein in the solid phase shortly after SC drink ingestion. These data support the concept of slow (MC) and rapid (SC) casein depending of casein structure, likely due to their intra-gastric clotting properties.

Background: Alternative, sustainable, and adequate sources of protein must be found to meet global demand. Objectives: Our aim was to assess the effect of a plant protein blend with a good balance of indispensable amino acids and high contents of leucine, arginine, and cysteine on the maintenance of muscle protein mass and function during aging in comparison to milk proteins and to determine if this effect varied according to the quality of the background diet. Methods: Old male Wistar rats (n 1/4 96, 18 mo old) were randomly allocated for 4 mo to 1 of 4 diets, differing according to protein source (milk or plant protein blend) and energy content (standard, 3.6 kcal/g, with starch, or high, 4.9 kcal/g, with saturated fat and sucrose). We measured: every 2 mo, body composition and plasma biochemistry; before and after 4 mo, muscle functionality; after 4 mo, in vivo muscle protein synthesis (flooding dose of L-[1 -13C]-valine) and muscle, liver, and heart weights. Two-factor ANOVA and repeated measures 2-fac-tor ANOVA were conducted. Results: There was no difference between protein type on the maintenance during aging of lean body mass, muscle mass, and muscle functionality. The high-energy diet significantly increased body fat (+47%) and heart weight (+8%) compared to the standard energy diet but had no effect on fasting plasma glucose and insulin. Muscle protein synthesis was significantly stimulated by feeding to the same extent in all groups (+13%). Conclusions: Since high-energy diets had little impact on insulin sensitivity and related metabolism, we could not test the hypothesis that in situations of higher insulin resistance, our plant protein blend may be better than milk protein. However, this rat study offers significant proof of concept from the nutritional standpoint that appropriately blended plant proteins can have high nutritional value even in demanding situations such as aging protein metabolism.

Impairment of gut function is one of the explanatory mechanisms of health status decline in elderly population. These impairments involve a decline in gut digestive physiology, metabolism and immune status, and associated to that, changes in composition and function of the microbiota it harbors. Continuous deteriorations are generally associated with the development of systemic dysregulations and ultimately pathologies that can worsen the initial health status of individuals. All these alterations observed at the gut level can then constitute a wide range of potential targets for development of nutritional strategies that can impact gut tissue or associated microbiota pattern. This can be key, in a preventive manner, to limit gut functionality decline, or in a curative way to help maintaining optimum nutrients bioavailability in a context on increased requirements, as frequently observed in pathological situations. The aim of this review is to give an overview on the alterations that can occur in the gut during aging and lead to the development of altered function in other tissues and organs, ultimately leading to the development of pathologies. Subsequently is discussed how nutritional strategies that target gut tissue and gut microbiota can help to avoid or delay the occurrence of aging-related pathologies.

Wild-type and Mstn-/- tumor-bearing mice have similar caloric intakes, indicating that anorexia is not involved in the development of cancer cachexia.

This article critically reviews the state of knowledge on the quality of animal-source foods according to animal production and food processing conditions, including consumer expectations-behaviours and the effects of consumption of animal-source foods on human health. Quality has been defined through seven core attributes: safety, commercial, sensory, nutritional, technological, convenience, and image. Image covers ethical, cultural and environmental dimensions associated with the origin of the food and the way it is produced and processed. This framework enables to highlight the priorities given to the different quality attributes. It also helps to identify potential antagonisms and synergies among quality attributes, between production and processing stages, and among stakeholders. Primacy is essentially given to commercial quality attributes, especially for standard-commodity animal-source foods. This primacy has strongly influenced genetic selection and farming practices in all livestock commodity chains and enabled substantial quantitative gains, although at the expense of other quality traits. Focal issues are the destructuring of chicken muscle that compromises sensory, nutritional and image quality attributes, and the fate of males in the egg and dairy sectors, which have heavily specialized their animals. Quality can be gained but can also be lost throughout the farm-to-fork continuum. Our review highlights critical factors and periods throughout animal production and food processing routes, such as on-farm practices, notably animal feeding, pre-slaughter and slaughter phases, food processing techniques, and food formulation. It also reveals on-farm and processing factors that create antagonisms among quality attributes, such as the castration of male pigs, the substitution of marine-source feed by plant-based feed in fish, and the use of sodium nitrite in meat processing. These antagonisms require scientific data to identify trade-offs among quality attributes and/or solutions to help overcome these tensions. There are also food products that value synergies between quality attributes and between production and processing phases, particularly Geographical Indications. Human epidemiological studies have found associations between consumption of animal-source foods and increased or decreased risk for chronic non-communicable diseases. These associations have informed public health recommendations. However, they have not yet considered animal production and food processing conditions. A concerted and collaborative effort is needed from scientists working in animal science, food process engineering, consumer science, human nutrition and epidemiology in order to address this research gap. Avenues for research and main options for policy action are discussed.

Effect of human recombinant Mstn (hrMstn) on the proliferation of Lewis lung carcinoma (LLC) cells - Bcl-2 protein content in the tumor tissue.

Obesity is a major contributor to the silent and progressive development of type 2 diabetes (T2D) whose prevention could be improved if individuals at risk were identified earlier. Our aim is to identify early phenotypes that precede T2D in diet-induced obese minipigs. We fed four groups of minipigs (n = 5–10) either normal-fat or high-fat high-sugar diet during 2, 4, or 6 months. Morphometric features were recorded, and metabolomics and clinical parameters were assessed on fasting plasma samples. Multivariate statistical analysis on 46 morphometrical and clinical parameters allowed to differentiate 4 distinct phenotypes: NFC (control group) and three others (HF2M, HF4M, HF6M) corresponding to the different stages of the obesity progression. Compared to NFC, we observed a rapid progression of body weight and fat mass (4-, 7-, and tenfold) in obese phenotypes. Insulin resistance (IR; 2.5-fold increase of HOMA-IR) and mild dyslipidemia (1.2- and twofold increase in total cholesterol and HDL) were already present in the HF2M and remained stable in HF4M and HF6M. Plasma metabolome revealed subtle changes of 23 metabolites among the obese groups, including a progressive switch in energy metabolism from amino acids to lipids, and a transient increase in de novo lipogenesis and TCA-related metabolites in HF2M. Low anti-oxidative capacities and anti-inflammatory response metabolites were found in the HF4M, and a perturbed hexose metabolism was observed in HF6M. Overall, we show that IR and progressively obese minipigs reveal phenotype-specific metabolomic signatures for which some of the identified metabolites could be considered as potential biomarkers of early progression to TD2.

Plasma concentration of amino acids.

Lifespan of wild-type and Mstn-/- mice - Number of polyps.