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Dipeptidyl-peptidase IV (DPP-IV) plays an essential role in glucose metabolism by inactivating incretins. In this context, food-protein-derived DPP-IV inhibitors are promising glycemic regulators which may act by preventing the onset of type 2 diabetes in personalized nutrition. In this study, the DPP-IV-inhibitory potential of seven proteins from diverse origins was compared for the first time in vitro and in vivo in rat plasma after the intestinal barrier (IB) passage of the indigested proteins. The DPP-IV-inhibitory potentials of bovine hemoglobin, caseins, chicken ovalbumin, fish gelatin, and pea proteins were determined in rat plasma thirty minutes after oral administration. In parallel, these proteins, together with bovine whey and gluten proteins, were digested using the harmonized INFOGEST protocol adapted for proteins. The DPP-IV half-maximal inhibitory concentration (IC50) was determined in situ using Caco-2 cells. The DPP-IV-inhibitory activity was also measured after IB passage using a Caco2/HT29-MTX mixed-cell model. The peptide profiles were analyzed using reversed-phase high-performance liquid chromatography tandem mass spectrometry (RP-HPLC-MS/MS) with MS data bioinformatics management, and the IC50 of the identified peptides was predicted in silico. The in vitro and in vivo DPP-IV-inhibitory activity of the proteins differed according to their origin. Vegetable proteins and hemoglobin yielded the highest DPP-IV-inhibitory activity in vivo. However, no correlation was found between the in vivo and in vitro results. This may be partially explained by the differences between the peptidome analysis and the in silico predictions, as well as the study complexity.
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Diabetes Mellitus Tipo 2 , Inhibidores de la Dipeptidil-Peptidasa IV , Animales , Células CACO-2 , Digestión , Dipeptidil Peptidasa 4/metabolismo , Inhibidores de la Dipeptidil-Peptidasa IV/química , Inhibidores de la Dipeptidil-Peptidasa IV/farmacología , Humanos , Péptidos/química , Ratas , Espectrometría de Masas en TándemRESUMEN
Like their owners, dogs and cats are more and more affected by overweight and obesity-related problems and interest in functional pet foods is growing sharply. Through numerous studies, fish protein hydrolysates have proved their worth to prevent and manage obesity-related comorbidities like diabetes. In this work, a human in vitro static simulated gastrointestinal digestion model was adapted to the dog which allowed us to demonstrate the promising effects of a tilapia byproduct hydrolysate on the regulation of food intake and glucose metabolism. Promising effects on intestinal hormones secretion and dipeptidyl peptidase IV (DPP-IV) inhibitory activity were evidenced. We identify new bioactive peptides able to stimulate cholecystokinin (CCK) and glucagon-like peptide 1 (GLP-1) secretions, and to inhibit the DPP-IV activity after a transport study through a Caco-2 cell monolayer.
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Alimentación Animal , Tracto Gastrointestinal/fisiología , Péptidos/química , Hidrolisados de Proteína/química , Tilapia/metabolismo , Animales , Transporte Biológico , Células CACO-2 , Enfermedades de los Gatos/prevención & control , Gatos , Colecistoquinina/metabolismo , Dipeptidil Peptidasa 4/metabolismo , Enfermedades de los Perros/prevención & control , Perros , Productos Pesqueros , Hormonas Gastrointestinales , Péptido 1 Similar al Glucagón/metabolismo , Glucosa/metabolismo , Humanos , Hidrólisis , Técnicas In Vitro , Espectrometría de Masas , Sobrepeso , PorcinosRESUMEN
Consumers and governments have become aware how the daily diet may affect the human health. All proteins from both plant and animal origins are potential sources of a wide range of bioactive peptides and the large majority of those display health-promoting effects. In the meat production food chain, the slaughterhouse blood is an inevitable co-product and, today, the blood proteins remain underexploited despite their bioactive potentiality. Through a comparative food peptidomics approach we illustrate the impact of resolving power, accuracy, sensitivity, and acquisition speed of low-resolution (LR)- and high-resolution (HR)-LC-ESI-MS/MS on the obtained peptide mappings and discuss the limitations of MS-based peptidomics. From in vitro gastrointestinal digestions of partially purified bovine hemoglobin, we have established the peptide maps of each hemoglobin chain. LR technique (normal bore C18 LC-LR-ESI-MS/MS) allows us to identify without ambiguity 75 unique peptides while the HR approach (nano bore C18 LC-HR-ESI-MS/MS) unambiguously identify more than 950 unique peptides (post-translational modifications included). Herein, the food peptidomics approach using the most performant separation methods and mass spectrometers with high-resolution capabilities appears as a promising source of information to assess the health potentiality of proteins.
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Cromatografía Liquida/métodos , Digestión , Análisis de los Alimentos , Hemoglobinas/metabolismo , Péptidos/metabolismo , Proteómica , Espectrometría de Masas en Tándem/métodos , Animales , Bovinos , Técnicas In Vitro , Mapeo PeptídicoRESUMEN
This study aimed at showing the yeast diversity in feces of Algerian infants, aged between 1 and 24 months, hospitalized at Bejaia hospital (northeast side of the country). Thus, 20 colonies with yeast characteristics were isolated and identified using biochemical (ID32C Api system) and molecular (sequencing of ITS1-5.8S-ITS2 region) methods. Almost all colonies isolated (19 strains) were identified as Candida spp., with predominance of Candida albicans species, and one strain was identified as Saccharomyces cerevisiae. Screening of strains with inhibitory activities unveiled the potential of Candida parapsilosis P48L1 and Candida albicans P51L1 to inhibit the growth of Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 25923. Further studies performed with these two Candida strains revealed their susceptibility to clinically used antifungal compounds and were then characterized for their cytotoxicity and hemolytic properties. On the other hand, Saccharomyces cerevisiae P9L1 isolated as well in this study was shown to be devoid of antagonism but resulted safe and overall usable as probiotic.
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Biodiversidad , Heces/microbiología , Levaduras/aislamiento & purificación , Levaduras/fisiología , Argelia , Antifúngicos/farmacología , Candida/efectos de los fármacos , Candida/aislamiento & purificación , Candida/fisiología , Candida albicans/efectos de los fármacos , Candida albicans/aislamiento & purificación , Candida albicans/fisiología , Escherichia coli/crecimiento & desarrollo , Humanos , Lactante , Interacciones Microbianas , Saccharomyces cerevisiae/efectos de los fármacos , Saccharomyces cerevisiae/aislamiento & purificación , Saccharomyces cerevisiae/fisiología , Levaduras/efectos de los fármacosRESUMEN
Calcium is the most abundant mineral in the human body and is involved in critical physiological and cellular processes. It is essential for the development, maintenance, and integrity of bone tissue throughout life. Identifying new natural food-grade chelating agents to improve calcium uptake is of increasing interest. Casein phosphopeptides (CPPs), highly phosphorylated peptides obtained after enzymatic hydrolysis of caseins, represent promising calcium-chelating candidates. The aim of this study was to investigate, using cell culture models, the ability of a digested milk matrix enriched in CPPs to regulate calcium transport through the intestinal barrier and elucidate the involved mechanisms. To this end, a CPP-preparation underwent in vitro static digestion and was subsequently incubated with an intestinal barrier model to monitor calcium uptake and transport. Our results demonstrated that the digested CPP preparation enhanced the trans-epithelial calcium transport via paracellular pathways and that CPPs, identified by peptidomics, crossed the intestinal barrier in the same time.
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Calcio , Caseínas , Mucosa Intestinal , Fosfopéptidos , Caseínas/farmacología , Caseínas/metabolismo , Caseínas/química , Fosfopéptidos/farmacología , Fosfopéptidos/metabolismo , Fosfopéptidos/química , Humanos , Calcio/metabolismo , Mucosa Intestinal/metabolismo , Mucosa Intestinal/efectos de los fármacos , Células CACO-2 , Transporte Biológico , Animales , Digestión , Absorción Intestinal/efectos de los fármacosRESUMEN
The ability of Paenibacillus polymyxa to inhibit the growth of Escherichia coli generic ATCC 25922 (Escherichia coli ATCC 25922) and to adhere to monolayers of the enterocyte-like human cell line Caco-2 was evaluated. P. polymyxa JB-0501 (P. polymyxa JB-0501), found in a livestock feed probiotic supplement, was compared to P. polymyxa reference strain ATCC 43685 and ATCC 7070 (P. polymyxa ATCC) in terms of carbohydrate utilization and resistance to lysozyme, acid, bile salts, and hydrogen peroxide. JB-0501 grew at pH 4.5 and at H2O2 concentrations less than 7.3 µg/ml and presented a higher affinity to hexadecane and decane. Bile salts at 0.2 % inhibited the growth of all three strains. P. polymyxa JB-0501 and P. polymyxa ATCC 43865 adhered to Caco-2 cell monolayers. The percentage of cells that adhered ranged from about 0.35 to 6.5 % and was partially proportional to the number applied. Contact time (from 15 min to 1 h) had little impact on adhesion. P. polymyxa JB-0501 inhibited the growth of E. coli ATCC 25922, as proven by the diffusion tests in agar. Taken together, these results suggested that P. polymyxa JB-0501 has the potential probiotic properties to justify its consideration as a livestock feed supplement.
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Paenibacillus/fisiología , Probióticos , Antibiosis , Adhesión Bacteriana , Ácidos y Sales Biliares/farmacología , Células CACO-2 , Metabolismo de los Hidratos de Carbono , Escherichia coli/crecimiento & desarrollo , Ácido Gástrico , Humanos , Peróxido de Hidrógeno/farmacología , Concentración de Iones de Hidrógeno , Muramidasa/farmacología , Paenibacillus/crecimiento & desarrolloRESUMEN
Research on new strategies to regulate glucose homeostasis to prevent or manage type 2 diabetes is a critical challenge. Several studies have shown that protein-rich diets could improve glucose homeostasis. Whey protein hydrolysis allows the release of amino acids and bioactive peptides, which exert numerous well-documented bioactivities. This study evaluates and compares the hypoglycemic potential of a whey protein hydrolysate and a whey protein isolate after static in vitro simulated gastrointestinal digestion (SGID) using the INFOGEST protocol. The peptide molecular mass distributions of the digested samples were evaluated by size exclusion chromatography and show that after digestion, the whey hydrolysate is significantly more hydrolyzed. After SGID, the whey protein hydrolysate induces a significative greater secretion of GLP-1 after two hours of contact with the enteroendocrine STC-1 cell line than the whey protein after isolation. In addition, the digested whey hydrolysate increases preproglucagon (GCG) and pro-convertase-1 (PCSK1) expression. The digested hydrolysate also inhibits the DPP-IV activity after an intestinal barrier passage challenge using a Caco-2/HT29-MTX mixed-cell model. Our results highlight that the prehydrolysis of whey proteins modify the intestinal peptidome, leading to a potentially greater hypoglycemic effect. This study confirms the previously observed in vitro hypoglycemic effect of this hydrolysate and evidences the beneficial impact of the industrial hydrolysis process.
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Diabetes Mellitus Tipo 2 , Humanos , Proteína de Suero de Leche/química , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Células CACO-2 , Hidrolisados de Proteína/farmacología , Hidrolisados de Proteína/química , Hipoglucemiantes/farmacología , Péptidos/farmacología , Homeostasis , GlucosaRESUMEN
Bioinformatics software, allowing the identification of peptides by the comparison of peptide fragmentation spectra obtained by mass spectrometry versus targeted databases or directly by de novo sequencing, is now mandatory in peptidomics/proteomics approaches. Programming the identification software requires specifying, among other things, the mass measurement accuracy of the instrument and the digestion enzyme used with the number of missed cleavages allowed. Moreover, these software algorithms are able to identify a large number of post-translational modifications (PTMs). However, peptide and PTM identifications are challenging in the agrofood field due to non-specific cleavage sites of physiological- or food-grade enzymes and the number and location of PTMs. In this study, we show the importance of customized software programming to obtain a better peptide and PTM identification rate in the agrofood field. A gelatine product and one industrial gelatine hydrolysate from three different sources (beef, pork, and fish), each digested by simulated gastrointestinal digestion, MS-grade trypsin, or both, were used to perform the comparisons. Two main points are illustrated: (i) the impact of the set-up of specific enzyme versus no specific enzyme use and (ii) the impact of a maximum of six PTMs allowed per peptide versus the standard of three. Prior knowledge of the composition of the raw proteins is an important asset for better identification of peptide sequences.
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OBJECTIVE: The aim of this study was to analyze the protein digestibility and postprandial metabolism in rats of milk protein matrices obtained by different industrial processes. MATERIAL AND METHODS: The study was conducted on Wistar rats that consumed a meal containing different 15N-labeled milk proteins. Four milk matrices were tested: native micellar caseins (C1), caseins low in calcium (C2 low Ca2+), a matrix containing a ratio 63:37 of caseins and whey proteins (CW2) and whey proteins alone (W). Blood and urine were collected during the postprandial period and rats were euthanized 6 h after meal intake to collect digestive contents and organs. RESULTS: Orocaecal digestibility values of amino acids ranged between 96.0 ± 0.2% and 96.6 ± 0.4% for C1-, C2 low Ca2+- and W-matrices, while this value was significantly lower for CW2 matrix (92.4 ± 0.5%). More dietary nitrogen was sequestered in the splanchnic area (intestinal mucosa and liver) as well as in plasma proteins after ingestion of W matrix, especially compared to the C1- and C2 low Ca2+-matrices. Peptidomic analysis showed that more milk protein-derived peptides were identified in the caecum of rats after the ingestion of the matrices containing caseins compared to W matrix. CONCLUSION: We found that demineralization of micellar caseins did not modify its digestibility and postprandial metabolism. The low digestibility of the modified casein-to-whey ratio matrix may be ascribed to a lower accessibility of the protein to digestive enzymes due to changes in the protein structure, while the higher nitrogen splanchnic retention after ingestion of whey was probably due to the fast assimilation of its protein content. Finally, our results showed that industrial processes that modify the structure and/or composition of milk proteins influence protein digestion and utilization.
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Aminoácidos , Proteínas de la Leche , Ratas , Animales , Proteínas de la Leche/química , Aminoácidos/metabolismo , Caseínas/química , Proteína de Suero de Leche , Periodo Posprandial , Ratas Wistar , Nitrógeno/metabolismo , PéptidosRESUMEN
Mass spectrometry has become the technique of choice for the assessment of a high variety of molecules in complex food matrices. It is best suited for monitoring the evolution of digestive processes in vivo and in vitro. However, considering the variety of equipment available in different laboratories and the diversity of sample preparation methods, instrumental settings for data acquisition, statistical evaluations, and interpretations of results, it is difficult to predict a priori the ideal parameters for optimal results. The present work addressed this uncertainty by executing an inter-laboratory study with samples collected during in vitro digestion and presenting an overview of the state-of-the-art mass spectrometry applications and analytical capabilities available for studying food digestion. Three representative high-protein foods - skim milk powder (SMP), cooked chicken breast and tofu - were digested according to the static INFOGEST protocol with sample collection at five different time points during gastric and intestinal digestion. Ten laboratories analysed all digesta with their in-house equipment and applying theirconventional workflow. The compiled results demonstrate in general, that soy proteins had a slower gastric digestion and the presence of longer peptide sequences in the intestinal phase compared to SMP or chicken proteins, suggesting a higher resistance to the digestion of soy proteins. Differences in results among the various laboratories were attributed more to the peptide selection criteria than to the individual analytical platforms. Overall, the combination of mass spectrometry techniques with suitable methodological and statistical approaches is adequate for contributing to the characterisation of the recently defined digestome.
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Digestión , Proteínas de Soja , Animales , Proteínas de Soja/metabolismo , Leche/química , Péptidos/análisis , Espectrometría de MasasRESUMEN
In this study, we investigate the interactions between the leaderless class IIb bacteriocin, enterocin DD14 (EntDD14), or the methicillin or the combination of these antibacterials, and two methicillin-resistant Staphylococcus aureus strains (MRSA-S1 and USA 300) which are respectively a clinical strain and a reference strain. The results obtained showed that EntDD14 alone or in combination with the antibiotic could significantly prevent the adhesion of these pathogenic bacteria to human cells. On the other hand, we investigated the anti-inflammatory effect of EntDD14 on the secretion of pro-inflammatory interleukins, including IL-6 and IL-8. The results show that EntDD14 is able to decrease significantly the secretion of both interleukins on Caco-2 cells following their treatments with lipopolysaccharides. These novel data provide insightful informations to support applications of bacteriocins as therapeutic agents capable as well to defeat pathogenic bacteria and concomitantly limit their inflammatory reactions.
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Bacteriocinas , Staphylococcus aureus Resistente a Meticilina , Antibacterianos/farmacología , Antiinflamatorios/farmacología , Bacterias , Bacteriocinas/farmacología , Hidrocarburos Aromáticos con Puentes , Células CACO-2 , HumanosRESUMEN
Milk and dairy products are significant sources of proteins and peptides impacting human health. In this way, the interest in CPPs, bioactive phosphorylated peptides resulting from the hydrolysis of caseins, has grown in the past years. CPPs were mainly studied for their capacity to chelate and increase the bioavailability of essential minerals involved in multiple physiological processes. Moreover, CPPs harbour interesting antioxidant and anti-inflammatory properties. Recent in vivo and in vitro studies demonstrated that these different roles are strongly linked to the intrinsic properties of CPPs and CPP concentrate preparations. This review first comments on the different methods of CPP analytical characterization, focusing on recent techniques. Then, the CPP release occurring during the gastrointestinal digestion was reviewed, followed by the different CPP obtention processes and their impact on their physicochemical characteristics. Finally, the different bioactive roles attributed to CPPs, including mineral chelating properties, are discussed. We show that CPPs have a promising role in treating various pathologies, notably to compensate for deficiencies in certain nutrients and an anti-oxidant and anti-inflammatory role. Nevertheless, the mechanisms by which CPPs exert their role remain to be elucidated, and this requires precise characterization of CPPs. This work highlights the key parameters to be considered to study and produce CPPs and the different ways to be investigated in the future to elucidate their roles in vivo and characterize their potential for human health.
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Caseínas , Fosfopéptidos , Animales , Disponibilidad Biológica , Caseínas/química , Humanos , Leche/química , Minerales/análisis , Fosfopéptidos/químicaRESUMEN
ESKAPE pathogens are considered as global threats to human health. The discovery of new molecules for which these pathogens have not yet developed resistance is a high medical priority. Synthetic flavonoids are good candidates for developing new antimicrobials. Therefore, we report here the potent in vitro antibacterial activity of BrCl-flav, a representative of a new class of synthetic tricyclic flavonoids. Minimum inhibitory/bactericidal concentration, time kill and biofilm formation assays were employed to evaluate the antibacterial potential of BrCl-flav. The mechanism of action was investigated using fluorescence and scanning electron microscopy. A checkerboard assay was used to study the effect of the tested compound in combination with antibiotics. Our results showed that BrCl-flav displayed important inhibitory activity against all tested clinical isolates, with MICs ranging between 0.24 and 125 µg/mL. A total kill effect was recorded after only 1 h of exposing Enterococcus faecium cells to BrCl-flav. Additionally, BrCl-flav displayed important biofilm disruption potential against Acinetobacter baumannii. Those effects were induced by membrane integrity damage. BrCl-flav expressed synergistic activity in combination with penicillin against a MRSA strain. Based on the potent antibacterial activity, low cytotoxicity and pro-inflammatory effect, BrCl-flav has good potential for developing new effective drugs against ESKAPE pathogens.
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Industrial chicory has been the subject of numerous studies, most of which provide clinical observations on its health effects. Whether it is the roasted root, the flour obtained from the roots or the different classes of molecules that enter into the composition of this plant, understanding the molecular mechanisms of action on the human organism remains incomplete. In this study, we were interested in three molecules or classes of molecules present in chicory root: fructose, chlorogenic acids, and sesquiterpene lactones. We conducted experiments on the murine model and performed a nutrigenomic analysis, a metabolic hormone assay and a gut microbiota analysis, associated with in vitro observations for different responses. We have highlighted a large number of effects of all these classes of molecules that suggest a pro-apoptotic activity, an anti-inflammatory, antimicrobial, antioxidant, hypolipidemic and hypoglycemic effect and also an important role in appetite regulation. A significant prebiotic activity was also identified. Fructose seems to be the most involved in these activities, contributing to approximately 83% of recorded responses, but the other classes of tested molecules have shown a specific role for these different effects, with an estimated contribution of 23-24%.
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Cichorium intybus , Animales , Antiinflamatorios/metabolismo , Cichorium intybus/metabolismo , Ácido Clorogénico/metabolismo , Alimentos Funcionales , Humanos , Ratones , Prebióticos/análisisRESUMEN
Several studies have demonstrated that high protein diets improve glucose homeostasis. Nevertheless, the mechanisms underlying this effect remain elusive. This exploratory study aims to screen and compare the acute effects of dietary proteins from different sources on intestinal glucose absorption. Six dietary proteins from various sources were thus selected and digested thanks to the INFOGEST static gastrointestinal digestion protocol. The digested proteins were able to decrease intestinal glucose absorption in vitro and ex vivo. Moreover, acute ingestion of casein and fish gelatin led to improved glucose tolerance in Wistar rats without significant effect on insulin secretion. In parallel, GLUT2 mRNA expression in enterocytes was decreased following short-term incubation with some of the digested proteins. These results strengthen the evidence that digested protein-derived peptides and amino acids are key regulators of glucose homeostasis and highlight their role in intestinal glucose absorption.
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Since alterations of the gut microbiota have been shown to play a major role in obesity, probiotics have attracted attention. Our aim was to identify probiotic candidates for the management of obesity using a combination of in vitro and in vivo approaches. We evaluated in vitro the ability of 23 strains to limit lipid accumulation in adipocytes and to enhance the secretion of satiety-promoting gut peptide in enteroendocrine cells. Following the in vitro screening, selected strains were further investigated in vivo, single, or as mixtures, using a murine model of diet-induced obesity. Strain Bifidobacterium longum PI10 administrated alone and the mixture of B. animalis subsp. lactis LA804 and Lactobacillus gasseri LA806 limited body weight gain and reduced obesity-associated metabolic dysfunction and inflammation. These protective effects were associated with changes in the hypothalamic gene expression of leptin and leptin receptor as well as with changes in the composition of gut microbiota and the profile of bile acids. This study provides crucial clues to identify new potential probiotics as effective therapeutic approaches in the management of obesity, while also providing some insights into their mechanisms of action.
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Adipocitos/microbiología , Células Enteroendocrinas/microbiología , Microbioma Gastrointestinal/fisiología , Obesidad/microbiología , Probióticos/farmacología , Animales , Ácidos y Sales Biliares/metabolismo , Dieta/efectos adversos , Modelos Animales de Enfermedad , Hormonas Gastrointestinales/metabolismo , Hipotálamo/metabolismo , Leptina/metabolismo , Ratones , Obesidad/etiología , Manejo de la Obesidad/métodos , Receptores de Leptina/metabolismo , Aumento de Peso/fisiologíaRESUMEN
Breast milk is the gold standard in neonatal nutrition, but most infants are fed infant formulas in which lipids are usually of plant origin. The addition of dairy lipids and/or milk fat globule membrane extracts in formulas improves their composition with beneficial consequences on protein and lipid digestion. The probiotic Lactobacillus fermentum (Lf) was reported to reduce transit time in rat pups, which may also improve digestion. This study aimed to investigate the effects of the addition of dairy lipids in formulas, with or without Lf, on protein and lipid digestion and on gut physiology and metabolism. Piglets were suckled from postnatal days 2 to 28, with formulas containing either plant lipids (PL), a half-half mixture of plant and dairy lipids (DL), or this mixture supplemented with Lf (DL+Lf). At day 28, piglets were euthanized 90 min after their last feeding. Microstructure of digesta did not differ among formulas. Gastric proteolysis was increased (P < 0.01) in DL and DL+Lf (21.9 ± 2.1 and 22.6 ± 1.3%, respectively) compared with PL (17.3 ± 0.6%) and the residual proportion of gastric intact caseins decreased (p < 0.01) in DL+Lf (5.4 ± 2.5%) compared with PL and DL (10.6 ± 3.1% and 21.8 ± 6.8%, respectively). Peptide diversity in ileum and colon digesta was lower in PL compared to DL and DL+Lf. DL and DL+Lf displayed an increased (p < 0.01) proportion of diacylglycerol/cholesterol in jejunum and ileum digesta compared to PL and tended (p = 0.07) to have lower triglyceride/total lipid ratio in ileum DL+Lf (0.019 ± 0.003) as compared to PL (0.045 ± 0.011). The percentage of endocrine tissue and the number of islets in the pancreas were decreased (p < 0.05) in DL+Lf compared with DL. DL+Lf displayed a beneficial effect on host defenses [increased goblet cell density in jejunum (p < 0.05)] and a trophic effect [increased duodenal (p = 0.09) and jejunal (p < 0.05) weights]. Altogether, our results demonstrate that the addition of dairy lipids and probiotic Lf in infant formula modulated protein and lipid digestion, with consequences on lipid profile and with beneficial, although moderate, physiological effects.
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Bovine whey protein concentrate (WPC) was hydrolysed under pH-stat (ST) and non pH-controlled (free-fall, FF) conditions using Debitrase (DBT) and FlavorPro Whey (FPW). The resultant whey protein hydrolysates (WPHs) were assessed for the impact of hydrolysis conditions on the physicochemical and the in vitro antioxidant and intracellular reactive oxygen species (ROS) generation in oxidatively stressed HepG2 cells. Enzyme and hydrolysis condition dependent differences in the physicochemical properties of the hydrolysates were observed, however, the extent of hydrolysis was similar under ST and FF conditions. Significantly higher (p < 0.05) in vitro and cellular antioxidant activities were observed for the DBT compared to the FPW-WPHs. The WPHs generated under ST conditions displayed significantly higher (p < 0.05) oxygen radical absorbance capacity (ORAC) and Trolox equivalent antioxidant capacity (TEAC) values compared to the FF-WPHs. The impact of hydrolysis conditions was more pronounced in the in vitro compared to the cellular antioxidant assay. WPH peptide profiles (LC-MS/MS) were also enzyme and hydrolysis conditions dependent as illustrated in the case of ß-lactoglobulin. Therefore, variation in the profiles of the peptides released may explain the observed differences in the antioxidant activity. Targeted generation of antioxidant hydrolysates needs to consider the hydrolysis conditions and the antioxidant assessment method employed.
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Production of bioactive peptides (BAPs) by Lactobacillus species is a cost-effective approach compared to the use of purified enzymes. In this study, proteolytic Lactobacillus helveticus strains were used for milk fermentation to produce BAPs capable of inhibiting angiotensin converting enzyme (ACE). Fermented milks were produced in bioreactors using batch mode, and the resulting products showed significant ACE-inhibitory activities. However, the benefits of fermentation in terms of peptide composition and ACE-inhibitory activity were noticeably reduced when the samples (fermented milks and non-fermented controls) were subject to simulated gastrointestinal digestion (GID). Introducing an ultrafiltration step after fermentation allowed to prevent this effect of GID and restored the effect of fermentation. Furthermore, an integrated continuous process for peptide production was developed which led to a 3 fold increased peptide productivity compared to batch production. Using a membrane bioreactor allowed to generate and purify in a single step, an active ingredient for ACE inhibition.
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The gastrointestinal digestion of food proteins can generate peptides with a wide range of biological activities. In this study, we screened various potential bioactivities generated by plant-based proteins. Whey protein as an animal protein reference, five grades of pea protein, two grades of wheat protein, and potato, fava bean, and oat proteins were submitted to in vitro SGID. They were then tested in vitro for several bioactivities including measures on: (1) energy homeostasis through their ability to modulate intestinal hormone secretion, to inhibit DPP-IV activity, and to interact with opioid receptors; (2) anti-hypertensive properties through their ability to inhibit ACE activity; (3) anti-inflammatory properties in Caco-2 cells; (4) antioxidant properties through their ability to inhibit production of reactive oxygen species (ROS). Protein intestinal digestions were able to stimulate intestinal hormone secretion by enteroendocrine cells, to inhibit DPP-IV and ACE activities, to bind opioid receptors, and surprisingly, to decrease production of ROS. Neither pro- nor anti-inflammatory effects have been highlighted and some proteins lost their pro-inflammatory potential after digestion. The best candidates were pea, potato, and fava bean proteins.