Effets des fructo-oligosaccharides sur la sensibilité à l'insuline

Une consommation de fibres alimentaires adéquate semble protéger du risque de développer un diabète de type 2 dont a contrario la prévalence ne cesse de progresser à travers le monde. Parmi les mécanismes d'action pouvant expliquer comment les fibres contribuent à l'homéostasie du glucose et à la sensibilité à l'insuline, l'implication du microbiote intestinal semble aujourd'hui très probable. Cependant il n'est pas toujours aisé de différencier ses effets de ceux pouvant découler d'une réduction de l'indice glycémique voir de ceux induits par des micronutriments parfois associés aux fibres. Les travaux de cette thèse ont permis de confirmer que les fructo-oligosaccharides (FOS), fibres prébiotiques peu visqueuses, peuvent améliorer la sensibilité à l'insuline de différents modèles animaux d'obésité induite par le régime alimentaire. La réduction de la sensibilité à l'insuline induite par le surpoids n'est pas complètement contrebalancée par les FOS mais leurs effets sont visibles même sans perte de poids associée. D'autre part une corrélation directe entre les modifications de la composition et des activités du microbiote intestinale induites par les FOS et le métabolisme de l'hôte a pu être mise en évidence. Au-delà d'une augmentation des bifidobactéries déjà bien documentée, les travaux de cette thèse ont révélé la modulation par les FOS d'autres clusters bactériens plus prépondérants au sein de l'écosystème digestif comme ceux des Clostridium leptum et Clostridium coccoides – Eubacterium rectale. En modulant ces populations, les FOS influencent le métabolisme des acides biliaires et le niveau d'hydroxylation d'acides gras monoinsaturés.An adequate intake of dietary has proven to protect against the risk to develop type 2 diabetes, for which the prevalence is currently increasing all around the world. Among the different mechanisms that could explain how dietary fibres can contribute to insulin sensitivity and glucose homeostasis, involvement of the gut microbiota seems more than likely. However it is not always possible to differentiate the effects that linked to the microbiota from those induced a reduction of the glycaemic index or those induced by some micronutrients sometimes closely associated to dietary fibres. The experiments conducted during this PhD validate that fructo-oligosaccharides (FOS), poorly viscous prebiotic fibres, can enhance insulin sensitivity if different animal models of diet-induced obesity. Reduction of insulin sensitivity resulting from overweight status is not completely solved by FOS but their effect is not linked to weight loss. Moreover, a direct correlation between the modifications of the composition and activities of the intestinal microbiota triggered by FOS and metabolism of the host has been highlighted. This work reveals that more than a single increase of Bifidobacteria already well documented, FOS can alter other bacterial clusters more predominant within the digestive ecosystem like Clostridium leptum and Clostridium coccoides – Eubacterium rectale. By modulating these populations, FOS will alter the metabolism of biliary acids and the level of monounsaturated fatty acids hydroxylation

Fructo-oligosaccharides and glucose homeostasis: a systematic review and meta-analysis in animal models

Abstract The aim of this systematic review was to assess the effect of fructo-oligosaccharide supplementation on glucose homeostasis. The search process was based on the selection of publications listed in the Pubmed-Medline database until April 2016 to identify studies evaluating the impact of short-chain fructo-oligosaccharides or oligofructose on glucose homeostasis. Twenty-nine trials were included in the systematic review and the meta-analysis was performed on twelve of these papers according to the inclusion criteria. Fasting blood concentrations of glucose and insulin were selected as pertinent criteria of glucose homeostasis for the meta-analysis. The consumption of fructo-oligosaccharides decreased fasting blood glycaemia levels, whatever the metabolic status (healthy, obese or diabetic) and diet (low-fat or high-fat) throughout the experiment. This reduction was linear with prebiotic dose (from 0 to 13% of the feed). Fasting insulinaemia also decreased linearly with fructo-oligosaccharide supplementation but the reduction was only significant in rodents fed a low-fat diet. Potential underlying mechanisms include gut bacterial fermentation of fructo-oligosaccharides to short-chain fatty acids (SCFA) and bacterial modulation of bile acids, both interacting with host metabolism. This systemic review, followed by the meta-analysis, provides evidence that fructo-oligosaccharide supplementation has a significant effect on glucose homeostasis whatever the health status and diet consumed by animals

Use of maltodextrin for enhancing or improving cognition and/or stimulating brain development

The invention concerns the use of a maltodextrin or a composition comprising thereof as the main source of carbohydrates in infant nutrition during the early childhood of a mammal for improving or enhancing cognitive performance and/or stimulating brain development

Use of maltodextrin for enhancing or improving cognition and/or stimulating brain development

The invention concerns the use of a maltodextrin or a composition comprising thereof as the main source of carbohydrates in infant nutrition during the early childhood of a mammal for improving or enhancing cognitive performance and/or stimulating brain development

Use of maltodextrin for enhancing or improving cognition and/or stimulating brain development

The invention concerns the use of a maltodextrin or a composition comprising thereof as the main source of carbohydrates in infant nutrition during the early childhood of a mammal for improving or enhancing cognitive performance and/or stimulating brain development

A milk formula containing maltodextrin, vs. lactose, as main carbohydrate source, improves cognitive performance of piglets in a spatial task

In recent years, lactose-free and low-lactose infant formulas have been increasingly used. The impact of using different carbohydrates than lactose on later cognition of formula-fed infants remains, however, unknown. We examined the effects of providing formulas containing either digestible maltodextrin or lactose as main carbohydrate source (28% of total nutrient composition) on cognitive performance of piglets. Piglets received the formulas from 1 to 9 weeks of age and, starting at 12 weeks, were individually tested in a spatial holeboard task (n = 8 pens/formula), in which they had to learn and memorize a configuration of baited buckets. After 28 acquisition trials, piglets were subjected to 16 reversal trials in which the location of the baited buckets was changed. Piglets fed the maltodextrin-based formula had higher reference memory (RM) scores than piglets fed the lactose-based formula towards the end of acquisition. During the switch of configuration, piglets offered the maltodextrin-based formula tended to have higher RM scores and make fewer RM errors than piglets offered the lactose-based formula. Working (short-term) memory was not affected by the formulas. Compared to lactose, the use of maltodextrin in milk formulas improved long-term spatial memory of piglets, even weeks after the end of the intervention

Perinatal prebiotic supplementation has later consequences on adult metabolism and immunity in pig as human model

Perinatal nutrition, a key factor controlling gut bacterial colonization, may have lasting consequences on health. We investigated whether early short-chain fructooligosaccharide (scFOS) supplementation, known to well-balance microbiota, impacted adult metabolic and immunologic responses to a high-fat (HF) diet. Sows received a supplementation with scFOS or not for the last 4 weeks of gestation and the lactation. The scFOS supplementation was maintained in piglets weaned from scFOS sows till postnatal day (PND) 56. Twenty four piglets were then fed a standard diet until PND190, then a HF diet for 12 weeks. Early scFOS supplementation increased faecal short-chain fatty acid production after 3 weeks of HF diet but this effect was not observed later. Ongoing metagenomics analysis will give more insights on microbiota composition changes. Insulin response to a glucose challenge (IVGTT) tended to increase in scFOS group, but no other metabolic parameter was modified (lipid metabolism, basal glycaemia and insulinemia, insulin pancreatic content). Preliminary results showed a modulation of the pro-inflammatory cytokine secretion (IFNg , TNFa, IL-8) by ex vivo stimulated ileal explants and MLN cells, revealing a modification of local immunity orientation with perinatal scFOS supplementation. Our results underline the key role of early microbiota modulation on adult responses to a nutritional challenge

Imprinting power: early-life supplementation with prebiotic impacts immune system and energy metabolism in pigs subjected to challenge

International audienceImprinting power: early-life supplementation with prebiotic impacts immune system and energy metabolism in pigs subjected to challenge. 5. Beneficial Microbes Conferenc