Search

This study investigated the feasibility of using hyperspectral imaging (HSI) to characterize the diffusion of acid and water within food structures during gastric digestion. Two different sweet potatoes (steamed and fried) and egg white gel (pH5 and pH9 EWGs) structures were exposed to in vitro gastric digestion before scanning by HSI. Afterward, the moisture or acid present in the digested sample was analyzed for calibration purposes. Calibration models were subsequently built using partial least-squares (PLS). The PLS models indicated that the full-wavelength spectral range (550–1700 nm) had a good ability to predict the spatial distribution of acid (Rcal2 > 0.82) and moisture (Rcal2 > 0.88). The spatiotemporal distributions of moisture and acid were mapped across the digested food, and they were shown to depend on the food composition and structure. The kinetic data revealed that the acid and moisture uptakes are governed by Fickian diffusion or by both diffusion and erosion-controlled mechanisms.

The use of probiotic bacteria derived from fermented foods has been explored by the scientific community as alternative strategies for the treatment of several diseases, mainly regarding intestinal dysfunction. One of the most relevant inflammatory diseases affecting the alimentary tract, for which no current intervention is entirely successful, is mucositis. In this review article, we summarize the most recent proof-of-concept studies dealing with the therapeutic use of dairy origin probiotics, for the treatment of gastrointestinal mucositis. Furthermore, we discuss several approaches for the improvement of the classical therapeutic rationale, such as supplementation with prebiotics and genetic engineering along with the respective translational issues, which may be crucial for the successful transposition of these therapeutic strategies for clinical use.

Objectives: Nutritional strategies can play a major role in the management of cholesterolemia, notably in postmenopausal women at risk of CVD. Interest has recently grown on the potential health benefitsof milk polar lipids (MPL).We showed that isolipidic enrichment of the diet with MPL improved several lipid CV risk factors but underlying mechanisms remained unclear. We hypothesized that MPL reduceintestinal cholesterol absorption in humans.Methods:We performed a double-blind randomized controlled trial in 58 postmenopausal women with fasting HDL-cholesterol < 1.6 mM.They were subjected to a 4-week dietary intervention with daily consumption of a cream-cheese containing 12 g of milk fat including either 0 g (control, n = 19), 3 g (n = 19) or 5 g (n = 20) of MPL. Before and after each intervention, blood lipids were measured in the whole cohortwhereas fecal lipids and coprostanol were analyzed in a subgroup (n = 7–9 per group). A proof-of-concept mechanistic crossover study was also carried out in 4 ileostomized subjects who performed 8hpostprandial tests after consuming 0g-, 3g- or 5g-MPL enriched cheese labelled with 2H-cholesterol tracer. Plasma, chylomicrons and ilealefflux were analyzed.Results: Milk fat enriched with 3 to 5 g MPL induced doseresponse reductions in serum total cholesterol (up to −6.8% in 5 g group, p < 0.05), LDL-cholesterol (−8.7%, p < 0.05) and HDL/total-cholesterol ratio (p < 0.001), compared to the control that had no effect. Fecal excretion of coprostanol increased after MPL supplementation (p < 0.05, 3g- and 5g-MPL vs control), and the fecal coprostanol/cholesterol ratio was inversely correlated with serum total- and LDL-cholesterol after intervention (r = −0.5, p < 0.05). In ileostomized subjects, postprandial accumulation of 2Hcholesterol in plasma and chylomicrons was reduced after 3 to 5 g MPL consumption (p < 0.05, vs control). Both cholesterol and milk sphingomyelin increased in ileal efflux after MPL enriched cheeses (p < 0.05).Conclusions: Present results suggest that milk polar lipids decrease cholesterol absorption in humans through interactions with sphingomyelin and by increasing conversion of cholesterol to coprostanol.Funding Sources: ANR (French National Research Agency, VALOBAB project, ANR-11-ALID-007–01), PHRC-I (French Clinical Research Program, 14–007), CNIEL (French Dairy Interbranch Organization).

The process of manufacturing infant milk formulas (IMFs) involves heat treatments that can lead to whey protein denaturation. The objective of the study was to determine how protein composition affects the denaturation kinetics of the whey proteins within IMFs. Three model IMFs (1.3% of cow’s milk protein) were produced with a caseins: whey proteins ratio of 40:60, differing only by the whey protein composition. The kinetics of heat-induced denaturation of α-lactalbumin, β-lactoglobulin and lactoferrin were investigated between 67.5 °C and 80 °C by chromatographic quantification of the residual native proteins. Results showed that the heat-denaturation of α-lactalbumin was reduced when β-lactoglobulin was absent. The heat-denaturation of lactoferrin was not affected by the composition of the IMFs but its presence enhanced the heat-denaturation of β-lactoglobulin. This study revealed that, for higher heat treatments (90 °C/15 s, 75 °C/15 min), IMF containing α-lactalbumin and lactoferrin preserved a higher proportion of native whey proteins than IMFs containing β-lactoglobulin.

Background The form of dietary nitrogen (free peptides or intact proteins) may influence the amount of endogenous amino acids found at the terminal ileum of the pig, and it has been speculated that hydrolyzed dietary protein may lead to increased endogenous amino acids. Objective To compare the effect of dietary free peptides on ileal endogenous nitrogen and amino acid flows [ileal endogenous nitrogen flow (ENFL), ileal endogenous amino acid flow (EAAFL)] with that of peptides released naturally from dietary protein during digestion, from the same intact parent protein source. Methods Six pigs (mean body weight: 34 kg) were equipped with a postvalve T-caecum cannula. Semisynthetic test diets contained the same 15N-labeled intact casein (C) or hydrolyzed casein (HC). Pigs received the test diets every sixth day and the corresponding unlabeled diets in the intervening 5-d periods. Digesta were pooled from 4 to 10 h postprandially. EAAFL and ENFL, calculated with reference to the dietary marker titanium dioxide, were determined by isotope dilution for C and HC. Results Ileal EAAFL and ENFL (mean flows n = 5 of 1828 and 1912 μg/g of dry matter intake for diets HC and C, respectively) did not differ (P > 0.05) between pigs fed HC and C. Centrifugation and ultrafiltration of the HC digesta allowed an estimation of label recycling into gut endogenous proteins. Some 20% of ileal endogenous protein (diet HC, ultrafiltered digesta) was 15N-labeled due to tracer recycling. Conclusions The administration of a casein hydrolysate had no effect on ileal endogenous protein flows compared with C. There was no evidence of enhanced ileal endogenous protein losses with the HC diet.

[Présentation orale].Les Journées Francophones de Nutrition (2018-11-28-2018-11-30) Nice (FRA). 2018.; Introduction et but de l’étudeLes maladies inflammatoires chroniques de l’intestin (MICI) sont reliées à divers facteurs, incluant le fond génétique, le système immunitaire, l’alimentation et d’autres facteurs environnementaux. Le microbiote intestinal est impliqué dans les MICI. La consommation de bactéries probiotiques sélectionnées peut induire ou prolonger des rémissions dans le cas de MICI telles que la RCH (rectocolite hémorragique). L’effet des bactéries consommées massivement dans les aliments fermentés est encore peu pris en compte. L’actinobactérie Propionibacterium freudenreichii est couramment consommée dans les fromages à pâte pressée cuite, ainsi que dans des compléments alimentaires probiotiques. Un grand nombre de souches sont disponibles pour cette espèce. Le but de cette étude était de :– rechercher l’aptitude de certaines souches à induire la cytokine modulatrice IL-10, au niveau de cellules immunitaires humaines (PBMC) ;– développer un fromage expérimental « monosouche » avec la souche la plus immunomodulatrice de P. freudenreichii ;– de tester l’impact de la consommation de ce fromage dans le contexte de la colite induite chez la souris.Matériel et méthodesLes propionibactéries ont été cultivées sur ultrafiltrat de lait de vache supplémenté en peptone de caséine puis conservées à -20°C dans du PBS glycérolé (1 milliard de bactéries par mL). La colite aiguë a été induite par administration intra-rectale de TNBS (100mg/kg de poids corporel) et les animaux euthanasiés après 3 jours d’induction. L’inflammation a été quantifiée par mesure des score macroscopique Wallace et microscopique Ameho. Les résultats sont exprimés comme des moyennes±SEM.Résultats et analyse statistiqueLa consommation de ce fromage a protégé les souris de la colite aiguë induite. L’induction de marqueurs locaux et systémiques de l’inflammation était réduite par la consommation du fromage. IL-6 : 366,17±134 versus 1726,7±548 pour le placebo (p˂0,05). SAA : 29 812±2909 versus 9535±2909 pour le placebo (p˂0,05). La consommation de fromage a également conduit à une forte diminution de l’expression colique des gènes Il6, Cox2 et Hmox, des scores cliniques et anatomopathologiques. En revanche, cette consommation a restauré l’expression de Pparg et de Zo1. Globalement, ces résultats démontrent un effet protecteur du fromage fermenté par P. freudenreichii, et pas du fromage placébo stérile, vis-à-vis de l’induction de la colite aiguë.ConclusionCette étude confirme le potentiel probiotique précédemment décrit pour la bactérie alimentaire P. freudenreichii. Elle propose un nouveau produit laitier fermenté, et ouvre de nouvelles perspectives, pour des études pré-cliniques et cliniques ultérieures, visant la prévention et/ou l’aide au traitement de maladies inflammatoires.

La santé constituant actuellement une des préoccupations majeures des consommateurs dans le domaine alimentaire, les industriels de l’agroalimentaire tentent de valoriser au mieux les caractéristiques nutritionnelles de leurs produits. Cette valorisation est pour l’instant principalement soumise à la responsabilité de ces industriels qui sont tenus de ne pas induire le consommateur en erreur. Le contrôle incombe à la Direction générale de la concurrence, de la consommation et de la répression des fraudes (DGCCRF) qui, selon les cas, peut interroger l’Agence française de sécurité sanitaire des aliments (Afssa) sur le fondement scientifique du message allégué. Toutefois, l’évolution alarmante de certains marqueurs de santé conduit les autorités compétentes à agir sur les différents facteurs susceptibles d’être impliqués dans cette évolution, dont la publicité. De nouvelles règles sont donc élaborées à Bruxelles, visant à améliorer le contrôle des allégations en leur soumettant notamment un régime d’autorisation préalable.