The influence of a formula supplemented with dairy lipids and plant oils on the erythrocyte membrane omega-3 fatty acid profile in healthy full-term infants : a double-blind randomized controlled trial

BACKGROUND: Human milk is the optimal nutrition for infants. When breastfeeding is not possible, supplementation of infant formula with long chain polyunsaturated fatty acids appears to promote neurodevelopmental outcome and visual function. Plant oils, that are the only source of fat in most of infant formulas, do not contain specific fatty acids that are present in human and cow milk and do not encounter milk fat triglyceride structure. Experimental data suggest that a mix of dairy lipids and plant oils can potentiate endogenous synthesis of n-3 long chain polyunsaturated fatty acids. This trial aims to determine the effect of an infant formula supplemented with a mixture of dairy lipids and plant oils on the erythrocyte membrane omega-3 fatty acid profile in full-term infants (primary outcome). Erythrocyte membrane long chain polyunsaturated fatty acids and fatty acids content, the plasma lipid profile and the insulin-growth factor 1 level, the gastrointestinal tolerance, the changes throughout the study in blood fatty acids content, in growth and body composition are evaluated as secondary outcomes. METHODS/DESIGN: In a double-blind controlled randomized trial, 75 healthy full-term infants are randomly allocated to receive for four months a formula supplemented with a mixture of dairy lipids and plant oils or a formula containing only plant oils or a formula containing plant oils supplemented with arachidonic acid and docosahexaenoic acid. Twenty-five breast-fed infants constitute the reference group. Erythrocyte membrane omega-3 fatty acid profile, long chain polyunsaturated fatty acids and the other fatty acids content, the plasma lipid profile and the insulin-growth factor 1 level are measured after four months of intervention. Gastrointestinal tolerance, the changes in blood fatty acids content, in growth and body composition, assessed by means of an air displacement plethysmography system, are also evaluated throughout the study. DISCUSSION: The achievement of an appropriate long chain polyunsaturated fatty acids status represents an important goal in neonatal nutrition. Gaining further insight in the effects of the supplementation of a formula with dairy lipids and plant oils in healthy full-term infants could help to produce a formula whose fat content, composition and structure is more similar to human milk. TRIAL REGISTRATION: ClinicalTrials.gov Identifier NCT01611649

Neural computations underpinning the strategic management of influence in advice giving

Research on social influence has focused mainly on the target of influence (e.g., consumer and voter); thus, the cognitive and neurobiological underpinnings of the source of the influence (e.g., politicians and salesmen) remain unknown. Here, in a three-sided advice-giving game, two advisers competed to influence a client by modulating their own confidence in their advice about which lottery the client should choose. We report that advisers’ strategy depends on their level of influence on the client and their merit relative to one another. Moreover, blood-oxygenation-level-dependent (BOLD) signal in the temporo-parietal junction is modulated by adviser’s current level of influence on the client, and relative merit prediction error affects activity in medial-prefrontal cortex. Both types of social information modulate ventral striatum response. By demonstrating what happens in our mind and brain when we try to influence others, these results begin to explain the biological mechanisms that shape inter-individual differences in social conduct

Impact of the dairy product structure and protein nature on the proteolysis and amino acid bioaccessiblity during in vitro digestion

Elderly people exhibit specific nutritional needs, in particular they require higher protein intake. Theobjective of this study was to compare, using an in vitro digestion protocol, the nutritional performanceof novel dairy products, based on whey proteins and which mimicked different commercial cheesetextures. Whey proteins have replaced caseins in these different gels for their known ability to promotemuscle synthesis in the elderly thanks to their high amount of leucine.The hydrolysis of proteins and the bioaccessibility of amino acids have been evaluated from thesimulated gastro-intestinal digestion of four whey-based products of identical composition but differentstructural properties. Heat-induced gelation of a whey-based dairy emulsion was performed by applyingdifferent combination of pH, stirring and heat treatment, in order to obtain a range of different gelstructures, from liquid to more or less firm and or whipped gels. A commercial Mozzarella cheese hasbeen tested as the casein-based control.Results showed that both the kinetics of protein hydrolysis and the amino acid release were significantlyhigher in the casein-based gel than in whey protein matrices. The extent of protein hydrolysis washigher in the whey protein gels compared to the liquid control sample, due to a facilitated hydrolysis ofthe heat-denatured proteins compared to native proteins. Peptide release and amino acid bioaccessibilitywere however not significantly influenced by the matrix structure. Further studies, using an in vivodigestion model will allow assessing the amino acids bioavailability of these matrices

Development of product for elderly people: impact of the type of protein and matrix structures on the protein hydrolysis

In 2030, 1/3 of the European population will be over 60 years old. Elderly people exhibit specific nutritional needs, in particular they require higher protein intake. For this purpose, three dairy products were developed to provide a large amount of whey protein, known to be quickly digested and rich in leucine. Whey proteins allow a peak of leucine stimulating the muscle protein synthesis.This study aimed to understand the influence of protein nature (whey or caseins), heat-induced protein denaturation and structure of the food matrix on the kinetics of proteolysis and the bioaccessibility of amino acids during a simulated gastrointestinal digestion. Three whey protein-based dairy products were designed with exactly the same composition (24% whey proteins, 20% fat) but different textures (more or less firm gels) were obtained by modulating the manufacturing process. The liquid and native whey protein emulsion was also studied as a control. Mozzarella cheese was studied as the casein gel control.A multiscale characterization of the matrices was conducted including texture analysis, microstructure by confocal microscopy, and extent of heat induced whey protein denaturation. Protein digestion rates and amino acid liberation kinetics during the in vitro gastro-intestinal digestion (based on the INFOGEST protocol) were evaluated using biochemical analyses of digesta.Results showed that both the degree of hydrolysis and the amino acid liberation were significantly higher in the casein-based gel than in whey protein matrices. The extent of protein hydrolysis was higher in the whey protein gels compared to the liquid control sample, due to a facilitated hydrolysis of the heat-denatured proteins compared to native proteins. Peptide release and amino acid bioaccessibility were however not significantly influenced by the matrix structure. Further studies, using an in vivo digestion model (in dynamic condition with gastric emptying) will allow to assess the amino acids bioavailability of these matrices

Development of product for elderly people: impact of the type of protein and matrix structures on the protein hydrolysis

In 2030, 1/3 of the European population will be over 60 years old. Elderly people exhibit specific nutritional needs, in particular they require higher protein intake. For this purpose, three dairy products were developed to provide a large amount of whey protein, known to be quickly digested and rich in leucine. Whey proteins allow a peak of leucine stimulating the muscle protein synthesis.This study aimed to understand the influence of protein nature (whey or caseins), heat-induced protein denaturation and structure of the food matrix on the kinetics of proteolysis and the bioaccessibility of amino acids during a simulated gastrointestinal digestion. Three whey protein-based dairy products were designed with exactly the same composition (24% whey proteins, 20% fat) but different textures (more or less firm gels) were obtained by modulating the manufacturing process. The liquid and native whey protein emulsion was also studied as a control. Mozzarella cheese was studied as the casein gel control.A multiscale characterization of the matrices was conducted including texture analysis, microstructure by confocal microscopy, and extent of heat induced whey protein denaturation. Protein digestion rates and amino acid liberation kinetics during the in vitro gastro-intestinal digestion (based on the INFOGEST protocol) were evaluated using biochemical analyses of digesta.Results showed that both the degree of hydrolysis and the amino acid liberation were significantly higher in the casein-based gel than in whey protein matrices. The extent of protein hydrolysis was higher in the whey protein gels compared to the liquid control sample, due to a facilitated hydrolysis of the heat-denatured proteins compared to native proteins. Peptide release and amino acid bioaccessibility were however not significantly influenced by the matrix structure. Further studies, using an in vivo digestion model (in dynamic condition with gastric emptying) will allow to assess the amino acids bioavailability of these matrices

Calcium in dairy matrices: in vitro digestion on the factors determining its bioaccessibility

International audienceCalcium is an essential mineral for the organism. Numerous calcium sources are available to enrich food but only calcium carbonate has been well studied. Calcium bioaccessibility depends mainly on solubility. Furthermore in vitro digestion allows to determine bioaccessibility and to identify the key parameters affecting it. This study focused on the influence of the gastro-intestinal pH, the food structure and the calcium source on the bioaccessibility of the nutrient. Four calcium sources (calcium carbonate, calcium citrate malate, dairy calcium phosphate and calcium bisglycinate) were added at 0.5% (w/w) in water (control), and in whey protein matrices as the liquid form or with heating to induce a gel. These matrices were digested under static conditions in duplicate, with the harmonized INFOGEST protocol [1]. Soluble and ionic calcium, and pH kinetics were followed during in vitro digestion. The kinetics were analyzed by nonparametric tests with repeated measurements. Results showed that all calcium sources were soluble in the matrices, mainly as ionic form (Ca2+), during the gastric phase at pH 3, but that calcium become insoluble in the intestinal compartment at pH 7. This rise in calcium insolubility led to a fall of the nutrient bioaccessibility from 20 to 80%. Dairy calcium phosphate had a distinct behavior with an important fall of solubility in the intestinal compartment due to strong ionic interactions between calcium and phosphate. In addition, the organization of whey proteins in the food matrix had no effect on solubilisation of calcium and therefore on its bioaccessibility. These results provide new insights to better understand bioavailability differences between calcium sources and matrices. Further in vivo digestion experiments on a pig model will be achieved in order to confirm bioaccessibility and to measure the bioavailability of those different sources of calcium. It will finally provide a relation between the results from in vitro and in vivo models of digestion

Calcium in dairy matrices: in vitro digestion on the factors determining its bioaccessibility

International audienceCalcium is an essential mineral for the organism. Numerous calcium sources are available to enrich food but only calcium carbonate has been well studied. Calcium bioaccessibility depends mainly on solubility. Furthermore in vitro digestion allows to determine bioaccessibility and to identify the key parameters affecting it. This study focused on the influence of the gastro-intestinal pH, the food structure and the calcium source on the bioaccessibility of the nutrient. Four calcium sources (calcium carbonate, calcium citrate malate, dairy calcium phosphate and calcium bisglycinate) were added at 0.5% (w/w) in water (control), and in whey protein matrices as the liquid form or with heating to induce a gel. These matrices were digested under static conditions in duplicate, with the harmonized INFOGEST protocol [1]. Soluble and ionic calcium, and pH kinetics were followed during in vitro digestion. The kinetics were analyzed by nonparametric tests with repeated measurements. Results showed that all calcium sources were soluble in the matrices, mainly as ionic form (Ca2+), during the gastric phase at pH 3, but that calcium become insoluble in the intestinal compartment at pH 7. This rise in calcium insolubility led to a fall of the nutrient bioaccessibility from 20 to 80%. Dairy calcium phosphate had a distinct behavior with an important fall of solubility in the intestinal compartment due to strong ionic interactions between calcium and phosphate. In addition, the organization of whey proteins in the food matrix had no effect on solubilisation of calcium and therefore on its bioaccessibility. These results provide new insights to better understand bioavailability differences between calcium sources and matrices. Further in vivo digestion experiments on a pig model will be achieved in order to confirm bioaccessibility and to measure the bioavailability of those different sources of calcium. It will finally provide a relation between the results from in vitro and in vivo models of digestion

Regulation of social hierarchy learning by serotonin transporter availability

Learning one's status in a group is a fundamental process in building social hierarchies. Although animal studies suggest that serotonin (5-HT) signaling modulates learning social hierarchies, direct evidence in humans is lacking. Here we determined the relationship between serotonin transporter (SERT) availability and brain systems engaged in learning social ranks combining computational approaches with simultaneous PET-fMRI acquisition in healthy males. We also investigated the link between SERT availability and brain activity in a non-social control condition involving learning the payoffs of slot machines. Learning social ranks was modulated by the dorsal raphe nucleus (DRN) 5-HT function. BOLD ventral striatal response, tracking the rank of opponents, decreased with DRN SERT levels. Moreover, this link was specific to the social learning task. These findings demonstrate that 5-HT plays an influence on the computations required to learn social ranks

Relationships between serotonin transporter rate and brain activity associated with learning of social ranks: a simultaneous TEP([11C]-DASB)-fMRI study in humans

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Bolus quality and food comfortability of model cheeses for the elderly as influenced by their texture

International audienceThe aim of this study was to examine the influence of the texture of dairy products on bolus properties and food comfortability as perceived by elderly persons. Four cheese models identical in terms of their nutritional composition but different by the type of texture (Soft, Hard, Processed and Whipped) were developed to resemble market cheese. Study was performed with a panel of 38 elderly persons without dental impairment but with variable rate of saliva flow. The time of chewing required to form the bolus was measured. The rheological properties of the bolus obtained were studied as well as the quantity of saliva incorporated. Food comfortability was assessed by means of a questionnaire asking about in-mouth comfort, bolus formation, pain, and perceived texture and flavor. Results showed that food comfortability was positively correlated to the ease of forming the bolus which depended on the food texture. Thus, the bolus formed with the Whipped product which required more saliva, was harder than the other three products and so judged the least comfortable. This product was characterized by a dry and sticky texture. On the other hand, the Soft and Processed products led to a softer food bolus that was more easily formed, and thus were judged as more comfortable. Their textures were perceived as soft, fatty and melting. This work highlights the importance of considering food bolus formation and related properties when looking for the link between food product characteristics and the enjoyment of eating in the case of the elderly population