A Mix of Dietary Fibres Changes Interorgan Nutrients Exchanges and Muscle-Adipose Energy Handling in Overfed Mini-Pigs.

This study evaluates the capacity of a bread enriched with fermentable dietary fibres to modulate the metabolism and nutrients handling between tissues, gut and peripheral, in a context of overfeeding. Net fluxes of glucose, lactate, urea, short chain fatty acids (SCFA), and amino acids were recorded in control and overfed female mini-pigs supplemented or not with fibre-enriched bread. SCFA in fecal water and gene expressions, but not protein levels or metabolic fluxes, were measured in muscle, adipose tissue, and intestine. Fibre supplementation increased the potential for fatty acid oxidation and mitochondrial activity in muscle (acox, ucp2, sdha and cpt1-m, p < 0.05) as well as main regulatory transcription factors of metabolic activity such as pparα, pgc-1α and nrf2. All these features were associated with a reduced muscle fibre cross sectional area, resembling to controls (i.e., lean phenotype). SCFA may be direct inducers of these cross-talk alterations, as their feces content (+52%, p = 0.05) was increased in fibre-supplemented mini-pigs. The SCFA effects could be mediated at the gut level by an increased production of incretins (increased gcg mRNA, p < 0.05) and an up-regulation of SCFA receptors (increased gpr41 mRNA, p < 0.01). Hence, consumption of supplemented bread with fermentable fibres can be an appropriate strategy to activate muscle energy catabolism and limit the establishment of an obese phenotype.

True ileal amino acid digestibility and digestible indispensable amino acid scores (DIAASs) of plant-based protein foods.

Plant-based protein foods are increasingly common, but data on their nutritional protein quality are scarce. This study evaluated it for seitan (wheat-based food), tofu (soya-based food), soya milk, and a pea emulsion. The true ileal digestibility (TID) of their amino acids was determined in minipigs, to calculate the digestible indispensable amino acid score (DIAAS). The TID of the proteins was high and not significantly different between the foods tested: 97% for seitan, 95% for tofu, 92% for soya milk and 94% for pea emulsion. There were only minor differences in individual amino acid TIDs. DIAAS ranking was thus essentially driven by the amino acid composition of the food: soya-based food > pea emulsion > seitan. Nevertheless, the lower TID of sulphur-containing amino acids in tofu than in soya milk induced a significant decrease in DIAAS (from 117% to 97%), highlighting the importance of the matrix effect on nutritional protein quality.

Temporal changes in postprandial intragastric pH: Comparing measurement methods, food structure effects, and kinetic modelling.

Intragastric pH greatly affects food disintegration and the release of nutrients in the gut. Here, the behaviour of two liquid meals (soymilk, pea emulsion) and two solid meals (tofu, seitan) was tested in miniature pigs fitted with gastric cannula. For 5 h, intragastric pH was recorded using one of three methods: ex vivo measurements of chyme samples, in situ measurements using pH catheters, or in situ measurements using wireless pH capsules, both inserted through a pig's cannula. The pH values obtained with the two in situ methods were highly correlated. The liquid and solid foods yielded distinct pH kinetics. For the solids, pH simply decreased exponentially. For the liquids, pH increased rapidly and then plateaued for 2 h before dropping Food macrostructure and, to a lesser extent, food buffering capacity clearly had an impact on intragastric pH. We modelled changes in intragastric pH over time with food-dependent nonlinear equations.

A mix of dietary fermentable fibers improves lipids handling by the liver of overfed minipigs.

Obesity induced by overfeeding ultimately can lead to nonalcoholic fatty liver disease, whereas dietary fiber consumption is known to have a beneficial effect. We aimed to determine if a supplementation of a mix of fibers (inulin, resistant starch and pectin) could limit or alleviate overfeeding-induced metabolic perturbations. Twenty female minipigs were fed with a control diet (C) or an enriched fat/sucrose diet supplemented (O + F) or not (O) with fibers. Between 0 and 56 days of overfeeding, insulin (+88%), HOMA (+102%), cholesterol (+45%) and lactate (+63%) were increased, without any beneficial effect of fibers supplementation. However, fibers supplementation limited body weight gain (vs. O, -15% at D56) and the accumulation of hepatic lipids droplets induced by overfeeding. This could be explained by a decreased lipids transport potential (-50% FABP1 mRNA, O + F vs. O) inducing a down-regulation of regulatory elements of lipids metabolism / lipogenesis (-36% SREBP1c mRNA, O + F vs. O) but not to an increased oxidation (O + F not different from O and C for proteins and mRNA measured). Glucose metabolism was also differentially regulated by fibers supplementation, with an increased net hepatic release of glucose in the fasted state (diet × time effect, P<.05 at D56) that can be explained partially by a possible increased glycogen synthesis in the fed state (+82% GYS2 protein, O + F vs. O, P=.09). The direct role of short chain fatty acids on gluconeogenesis stimulation is questioned, with probably a short-term impact (D14) but no effect on a long-term (D56) basis.