Impact of cooking and species on intestinal fermentation patterns of vegetables in a humanized in vitro model of the gastro-intestinal tract

Obesity and associated pathologies have dramatic consequences on patients’lives as well as high societal costs. Because of the role of intestinal dysbiosis and microbiota make-up on the pathogenesis of obesity, several strategies such as eating prebiotics and dietary fibre supplements are being investigated to reshape the intestinal microbial communities of obese patients. Beyond supplement, dietary fibre is supplied through plant ingredients in the meals. In the framework of the multidisciplinary research project Food4Gut, the use of vegetables rich in specific targeted dietary fiber, namely fructans, is being scrutinized for its ability to induce positive changes in the intestinal ecophysiology. Because expected effect might differ according the content in dietary fibre and fructans, the soluble:insoluble ratio, as well as the cooking of the vegetables, the fermentation patterns of several vegetables are being investigated in an dual in vitro model combining enzymatic hydrolysis to an in vitro fermentation step using faecal inoculums from humans, to evaluate the performance of gut microbiota, modulation of metabolic functions. Six vegetables were sampled in triplicates (N=3) and steamed for 20 to 30 min.: Jerusalem artichoke, salsify, asparagus, pumpkin, fennel and swede. They were chosen because they display a variety of contents in fructans, soluble (SDF) and insoluble dietaryfibre (IDF). Steamed vegetable samplesand burgers from local fast food restaurants (negative control) were hydrolyzed in vitro why porcine pepsin and pancreatin to mimic digestion in the upper gut and indigested fiber residues were recover using a 6kDa dialysis membrane.Subsequently, in vitro fermentation is being run with independent fecal inoculums from obese and lean patients (N=4). Fermentation kinetics over 24h as well as short-chain fatty acid production and profiles will be compared according to the individual donor and the vegetable species and multivariate analysis will be used to explore the relationships between donor, vegetable species and composition and fermentation patterns.Projet Food4 gu

Le profil en fibres alimentaires de légume modifie leur fermentation intestinale et la production d’acides gras à chaine courte dans modèle in vitro humain

La modulation du microbiote intestinal induite par les fibres alimentaires (DF)a des conséquences positives sur la santé, notamment sur l’obésité et ses comorbidités. La nature et l’ampleur des changements dépendent du type de fibres.Les légumes sont des sources privilégiées de DF, certaines espèces et variétés fournissant davantage de DF solubles (SDF), d’autres étant plus riches en DF insolubles (IDF). Contrairement aux SDF, les IDF sont souvent considérées comme peu fermentescibles, ne contribuant que faiblement à une modulation de l’écophysiologie intestinale. En opposition à cette hypothèse, pour explorer si l’impact potentiel sur la santé intestinale des légumes varie suivant leur nature, des légumes présentant des teneurs et des profils en DF différents ont été comparés dans un modèle in vitro de fermentation colique

Nonconventional enzymatic method to determine free asparagine level in whole-grain wheat

A new enzymatic methodology is herein proposed to measure free asparagine content in wheat grains and to predict their potential for Maillard reaction products. Our model estimates the acrylamide levels generated during the industrial heat treatment of whole-grain wheat based on free asparagine and glucose measurements. We selected fifteen wheat varieties currently grown in Belgium as benchmark for the present study. While conventional chromatographic methods require a long and tedious multi-step sample preparation, the proposed method takes advantage of being simple and quick. Statistical analysis of free asparagine content indicates that selected wheat varieties can be classified into seven content levels from 0.0149% to 0.0216% of the dry matter. Based on our analysis, the varieties KWS Ozon, Benchmark and Pionier appears to be the most suitable for thermal processing (i.e. cooking applications)

In vitro approach to evaluate the fermentation pattern of inulin-rich food in obese individuals.

Alterations of the gut microbiome have been associated with obesity and metabolic disorders. The gut microbiota can be influenced by the intake of dietary fibres with prebiotic properties, such as inulin-type fructans. This study tested the hypothesis that obese individuals subjected for 12 weeks to a inulin-enriched versus inulin-poor diet have differential faecal fermentation patterns. The fermentation of cellulose and inulin hydrolysates, of six different inulin-rich and inulin-poor vegetables of both groups was analysed in vitro on faecal inocula. The results showed that the microbiota from obese patients who received fructan-rich diet for three weeks produce more gas and total short-chain fatty acid (SCFA) compared to the microbiota taken of the same individuals before the treatment. Obese individuals fed with a low-fructan diet produce less gas and less SCFA compared to the treated group. This study highlighted profound changes in microbiota fermentation capacity obtained by prebiotic intervention in obese individuals, which favors the production of specific bioactive metabolites

In vitro approach to evaluate the fermentation pattern of inulin-rich food in obese individuals.

peer reviewedAlterations of the gut microbiome have been associated with obesity and metabolic disorders. The gut microbiota can be influenced by the intake of dietary fibres with prebiotic properties, such as inulin-type fructans. This study tested the hypothesis that obese individuals subjected for 12 weeks to a inulin-enriched versus inulin-poor diet have differential faecal fermentation patterns. The fermentation of cellulose and inulin hydrolysates, of six different inulin-rich and inulin-poor vegetables of both groups was analysed in vitro on faecal inocula. The results showed that the microbiota from obese patients who received fructan-rich diet for three weeks produce more gas and total short-chain fatty acid (SCFA) compared to the microbiota taken of the same individuals before the treatment. Obese individuals fed with a low-fructan diet produce less gas and less SCFA compared to the treated group. This study highlighted profound changes in microbiota fermentation capacity obtained by prebiotic intervention in obese individuals, which favors the production of specific bioactive metabolites