Dietary inulin intake and age can significantly affect intestinal absorption of calcium and magnesium in rats: a stable isotope approach

BACKGROUND: previous studies have shown that non-digestible inulin-type fructan intake can increase intestinal mineral absorption in both humans and animals. However, this stimulatory effect on intestinal absorption may depend on experimental conditions such as duration of fermentable fiber intake, mineral diet levels and animals' physiological status, in particular their age. OBJECTIVES: the aim of this study was to determine the effect of inulin intake on Ca and Mg absorption in rats at different age stages. METHODS: eighty male Wistar rats of four different ages (2, 5, 10 and 20 months) were randomized into either a control group or a group receiving 3.75% inulin in their diet for 4 days and then 7.5% inulin for three weeks. The animals were fed fresh food and water ad libitum for the duration of the experiment. Intestinal absorption of Ca and Mg was determined by fecal monitoring using stable isotopic tracers. Ca and Mg status was also assessed. RESULTS: absorption of Ca and Mg was significantly lower in the aged rats (10 and 20 mo) than in the young and adult rat groups. As expected, inulin intake increased Ca and Mg absorption in all four rat groups. However, inulin had a numerically greater effect on Ca absorption in aged rats than in younger rats whereas its effect on Mg absorption remained similar across all four rat age groups. CONCLUSION: the extent of the stimulatory effect of inulin on absorption of Ca may differ according to animal ages. Further studies are required to explore this effect over longer inulin intake periods, and to confirm these results in humans

Splanchnic metabolism of nutrients and hormones in steers fed alfalfa under conditions of increased absorption of ammonia and L-arginine supply across the portal-drained viscera

Effects of increased ammonia and/or arginine absorption on net splanchnic (portal-drained viscera [PDV] plus liver) metabolism of nonnitrogenous nutrients and hormones in cattle were examined. Six Hereford × Angus steers (501 ± 1 kg BW) prepared with vascular catheters for measurements of net flux across the splanchnic bed were fed a 75% alfalfa:25% (as-fed basis) corn and soybean meal diet (0.523 MJ of ME/[kg BW0.75.d]) every 2 h without (27.0 g of N/kg of DM) and with 20 g of urea/kg of DM (35.7 g of N/kg of DM) in a split-plot design. Net flux measurements were made immediately before and after a 72-h mesenteric vein infusion of L-arginine (15 mmol/h). There were no treatment effects onPDVor hepaticO2 consumption. Dietary urea had no effect on splanchnic metabolism of glucose or L-lactate, but arginine infusion decreased net hepatic removal of L-lactate when urea was fed (P < 0.01). Net PDV appearance of n-butyrate was increased by arginine infusion (P < 0.07), and both dietary urea (P < 0.09) and arginine infusion (P < 0.05) increased net hepatic removal of n-butyrate. Dietary urea also increased total splanchnic acetate output (P < 0.06), tended to increase arterial glucagon concentration (P < 0.11), and decreased arterial ST concentration (P < 0.03). Arginine infusion increased arterial concentration (P < 0.07) and net PDV release (P < 0.10) and tended to increase hepatic removal (P < 0.11) of insulin, as well as arterial concentration (P < 0.01) and total splanchnic output (P < 0.01) of glucagon. Despite changes in splanchnic N metabolism, increased ammonia and arginine absorption had little measurable effect on splanchnic metabolism of glucose and other nonnitrogenous components of splanchnic energy metabolism

Effect of a supplement rich in alkaline minerals on acid-base balance in humans

This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens

Arabinoxylan-oligosaccharides (AXOS) affect the protein/carbohydrate fermentation balance and microbial population dynamics of the Simulator of Human Intestinal Microbial Ecosystem

Arabinoxylan-oligosaccharides (AXOS) are a recently newly discovered class of candidate prebiotics as depending on their structure - they are fermented in different regions of gastrointestinal tract. This can have an impact on the protein/carbohydrate fermentation balance in the large intestine and, thus, affect the generation of potentially toxic metabolites in the colon originating from proteolytic activity. In this study, we screened different AXOS preparations for their impact on the in vitro intestinal fermentation activity and microbial community structure. Shortterm fermentation experiments with AXOS with an average degree of polymerization (avDP) of 29 allowed part of the oligosaccharides to reach the distal colon, and decreased the concentration of proteolytic markers, whereas AXOS with lower avDP were primarily fermented in the proximal colon. Additionally, prolonged supplementation of AXOS with avDP 29 to the Simulator of Human Intestinal Microbial Ecosystem (SHIME) reactor decreased levels of the toxic proteolytic markers phenol and p-cresol in the two distal colon compartments and increased concentrations of beneficial short-chain fatty acids (SCFA) in all colon vessels (25-48%). Denaturant gradient gel electrophoresis (DGGE) analysis indicated that AXOS supplementation only slightly modified the total microbial community, implying that the observed effects on fermentation markers are mainly caused by changes in fermentation activity. Finally, specific quantitative PCR (qPCR) analysis showed that AXOS supplementation significantly increased the amount of health-promoting lactobacilli as well as of Bacteroides-Prevotella and Clostridium coccoides-Eubacterium rectale groups. These data allow concluding that AXOS are promising candidates to modulate the microbial metabolism in the distal colon

Calf health from birth to weaning. II. Management of diarrhoea in pre-weaned calves

Calfhood diseases have a major impact on the economic viability of cattle operations. The second of this three part review series considers the management of diarrhoeic diseases in pre-weaned calves. In neonatal calf diarrhoea, oral rehydration therapy is the single most important therapeutic measure to be carried out by the farmer and is usually successful if instigated immediately after diarrhoea has developed. Continued feeding of milk or milk replacer to diarrhoeic calves is important, to prevent malnourishment and weight loss in affected calves. Indiscriminative antibiotic treatment of uncomplicated diarrhoea is discouraged, whereas systemically ill calves can benefit from systemic antibiotic treatment for the prevention of septicaemia or concurrent diseases. Ancillary treatments and specific preventive measures are discussed. Eimeriosis has a high economic impact on the farming industries due to direct cost of treatment and calf losses, but especially due to decreased performance of clinically as well as sub-clinically affected animals. Emphasis lies on prophylactic or metaphylactic treatment, since the degree of damage to the intestinal mucosa once diarrhoea has developed, makes therapeutic intervention unrewarding

Maîtrise des teneurs en vitamines B du pain et étude de la biodisponibilité de la thiamine du pain sur un modèle rat in vivo

Le pain constitue une part importante dans notre alimentation et est potentiellement une source majeure de minéraux et de vitamines B. Cependant le pain blanc, contrairement au pain complet, possède non seulement un index glycémique élevé mais il est également pauvre en vitamines B, en fibres et en minéraux. Aussi est il essentiel d'améliorer sa densité nutritionnelle afin de prévenir l'établissement de carences et/ou de sub-carences en vitamines B1 (thiamine), B2 (riboflavine) et B6 (pyridoxine), susceptibles d'affecter l'incidence des maladies cardio-vasculaires, de cancers, du diabète ou encore de maladies neurodégénératives. La maîtrise des teneurs en vitamines B du pain nécessite en amont un effort au niveau de la sélection variétale et en aval un effort au niveau des procédés de mouture et de panification. C'est pourquoi nous avons décidé de comparer les teneurs en vitamines dans un échantillon de 49 variétés de blé cultivées dans les mêmes conditions (Ménétrol, 2001). Il apparaît que les teneurs en thiamine, riboflavine et pyridoxine peuvent varier d'un facteur 2 à 3 selon les variétés et ces différences sont retrouvées dans les farines reconstituées, à la différence des farines blanches. Sur les 49 variétés de grains, des corrélations positives ont été observées entre les taux en protéines ou en minéraux et les teneurs en vitamines B (sauf entre les teneurs en riboflavine et en minéraux du grain). Le taux de protéines du grain constitue un marqueur intéressant de la teneur en pyridoxine dans le grain, les farines reconstituées et les pains correspondants. Cependant, le dosage de la vitamine elle-même dans le grain reste le meilleur marqueur du suivi des taux en thiamine et en riboflavine après mouture et panification. Ces recherches ont donc permis de mettre en évidence que la sélection variétale avait une influence sur les teneurs en vitamines B. Mais cette étude montre également d'importantes pertes en thiamine et en pyridoxine après la panification " conventionnelle " dans les pains blancs (37 à 62%). Par contre les pertes en thiamine et en pyridoxine dans le pain complet sont nettement moindre (31 et 37% respectivement). La maîtrise des conditions de panification passe par la détermination des étapes conditionnant la teneur en vitamines B du pain. Nous avons montré que plusieurs étapes sont susceptibles d'affecter les teneurs en vitamines B : le pétrissage, la fermentation et la cuisson. Le pétrissage trop intense diminue les teneurs en thiamine et en pyridoxine et la cuisson affecte les teneurs en pyridoxine. Plusieurs conditions de fermentation ont été testées et montrent l'influence du type de ferment utilisé et de la durée de fermentation. L'utilisation de la levure comme ferment et d'une durée de fermentation longue (6 heures) améliorent les teneurs finales en thiamine, riboflavine (quantité doublée) et en pyridoxine. Bien que l'utilisation du levain n'ait aucun effet sur les teneurs en riboflavine et pyridoxine, il reste cependant intéressant, pour optimiser les teneurs en thiamine dans les pains complets. Il paraît donc possible d'améliorer la densité nutritionnelle des pains complets en limitant les pertes en vitamines au cours de la panification. Sur un modèle de rat carencé en thiamine (8 jours), nous avons étudié l'effet de la consommation de pains (blanc ou complet) sur le statut thiaminique du rat. La carence utilisée conduit à une diminution drastique de la concentration plasmatique en thiamine (-95%) et à une déplétion plus ou moins forte en TDP (thiamine diphosphate), selon les tissus (foie>reins>cerveau). La restauration des teneurs en thiamine dans le cerveau est rapide (3 jours), quel que soit le régime, alors qu'elle nécessite au moins 14 jours dans le foie et les reins. La thiamine endogène du pain complet semble avoir une biodisponibilité comparable à la thiamine purifiée. Ce travail indique que la seule mesure des concentrations plasmatiques ou de l'excrétion urinaire de thiamine n'est pas suffisante pour refléter le statut en TDP des tissus. En conclusion, cette thèse ouvre de nouvelles perspectives quant à l'amélioration de la valeur nutritionnelle du pain. D'une part, grâce à la sélection variétale, il semble possible de proposer des variétés riches en vitamines et autres micronutriments, d'autre part grâce à l'optimisation des procédés de mouture et de panification, il serait possible de préserver ces caractéristiques et d'aboutir à des pains de haute densité nutritionnelle.CLERMONT FD-BCIU-Santé (631132104) / SudocPARIS-BIUP (751062107) / SudocSudocFranceF