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International audience; 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 foodsskim milk powder (SMP), cooked chicken breast and tofuwere 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.

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.

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.

Industrial chicory roots (Cichorium intybus var. sativum) have been the subject of many different studies investigating their supposed nutritional and medicinal benefits. Although an impressive number of clinical evidences has supported the health effects of this plant, the molecular mechanisms remain poorly understood. In this work, we looked at chicory flour that is proposed as an ingredient for pastries and a water extract of chicory root flour was tested. We experimented on the murine model and highlighted new mechanisms by which the chicory roots brings health benefits. For this purpose, a nutrigenomic analysis was associated with a metabolic hormone dosage and a metagenomic analysis. New potential mechanisms by which the chicory acts on cancer prevention on antibacterial and antiviral defense, on hypoglycemic and hypolipidemic effect as well as on the antioxidant effect were identified. Also, the prebiotic effect of the chicory root flour was discussed by comparison with inulin. In general, almost all effects were found to be more pronounced in male mice than in female mice.

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.

International audience; The identification of non-fermentative Gram negative bacilli from run-off and spring water, including fluorescent Pseudomonas is very complex and investigations are needed to contribute to the systematic of these bacteria. In this dataset, the phenotypical profiles of three strains isolated from Vosges mountains first identified as Pseudomonas fluorescens were determined using APIⓇ 50 CH galleries. Then, the identification of their proteins released directly into water was carried out using tandem/mass spectrometry after separating proteins on native two-dimensional polyacrylamide gels. Finally, genotypic analysis data is presented, that illustrates biodiversity in this fluorescent bacterial group. This data is referred by a research article entitled "Fluorescent Pseudomonas strains from mid-mountain water able to release antioxidant proteins directly into water".

International audience

International audience; To compensate for their amino acid auxotrophy, lactobacilli have developed the ability to hydrolyze proteins present in their environment. This proteolytic activity not only generates the free amino acids needed by the bacteria, but also a large variety of peptides, some of which are endowed with biological activities. These so-called "bioactive peptides" (BAPs) are interesting from a nutrition and healthcare perspective. The use of lactic acid bacteria (LAB) such as lactobacilli is an effective strategy for production and valorization of new BAPs. The proteolytic activity of lactobacilli is exerted in a strain-and species-dependent manner: each species exhibits different proteinase content, leading to a large variety of proteolytic activities. This underlines the high potential of Lactobacillus strains to produce novel hydrolysates and BAPs of major interest. This review aims at discussing the potential of different Lactobacillus species to release BAPs from fermentation media and processes. Strategies used for peptide production are presented. Additionally, we propose a methodology to select the most promising Lactobacillus strains as sources of BAPs. This methodology combines conventional approaches and in silico analyses.

Fish protein hydrolysates (FPH) are of interest due to their potential application as a source of bioactive peptides in the nutraceutics domain. To explore the possibility of obtaining biologically active molecules from hydrolysates of marine processing wastes, we looked for the presence of immunoreactivities and biological activities related to peptide hormones in fish hydrolysates. A principal aim of our work is to industrially produce marine ingredients that are beneficial for human health, and can, in a preventive manner, provide workable solutions to major public health issues such as migraine and obesity. Our study was focused on two hormonal groups of high use in therapeutics: the calcitonin gene related peptide (CGRP) and the gastrin / cholecystokinin (CCK). Blue whiting co-product hydrolysates were prepared by the Compagnie des Pêche Saint Malo Santé using the pH-stat method. The hydrolysis degree (DH) was calculated, and hydrolysates were analysed for the presence of gastrin / CCK related peptides using a specific radioimmuoassay. The CGRP related molecules were quantified by a radioreceptor assay developed using rat liver membranes, a specific target organ for CGRP in mammals. Three enzymes among the eight investigated were selected for their capacity to generate molecules related to gastrin / CCK and/or CGRP. Bioactive peptides accounted for 425 and 4 pg.mg-1 of dry weight for CGRP and CCK related peptides, respectively. In a second step, the best hydrolysis conditions for each of the selected enzymes were determined by quantifying bioactive peptides under various conditions of temperature, pH and enzyme substrate ratio. In parallel, the molecular weight repartition of peptides in each hydrolysate was determined by size exclusion chromatography (SEC-FPLC) coupled with GPC software. The resulting data showed no relationship between DH and peptide quantity obtained. Similarly, the molecular weight distribution under each experimental condition was not related to the quantity of bioactive peptides. Nonetheless, all these data suggest which hydrolysis conditions are the best for obtaining the peptides of interest. Further studies are in progress to determine the molecular weight of the peptides involved in biological activities. A Specific in vivo test for gastrin/CCK-like molecules is under development to study the mode of action and biological effects of the FPH purified fractions using pre-obese rats. To determine the receptor subtype involved in the CCK-like stimulation response, a test in vitro is in progress using AR4-2J cell line. A second in-vitro test, specific for CGRP related molecules, will assess the FPH effect on adenylate cyclase stimulation of CGRP-related molecules in rat liver membranes. Supported by a grant from the European community: .

The gut plays a central role in energy homeostasis. Food intake regulation strongly relies on the gut-brain axis, and numerous studies have pointed out the significant role played by gut hormones released from enteroendocrine cells. It is well known that digestive products of dietary protein possess a high satiating effect compared to carbohydrates and fat. Nevertheless, the processes occurring in the gut during protein digestion involved in the short-term regulation of food intake are still not totally unraveled. This review provides a concise overview of the current data concerning the implication of food-derived peptides in the peripheral regulation of food intake with a focus on the gut hormones cholecystokinin and glucagon-like peptide 1 regulation and the relationship with some aspects of glucose homeostasis.