膳食脂质消化行径及其影响机制研究进展

膳食脂质是肌体能量、必需营养物质和生物活性成分的重要来源或载体,其在体内的消化行径往往受到消化场所及存在形态差异的影响.本文通过对膳食脂质在胃肠道内不同阶段的消化行径进行综述,分析膳食脂质在各阶段消化过程中的变化,阐明了膳食脂质在机体代谢过程中与脂肪酶、胆盐的亲和机制,以及小肠内的微生物菌群与膳食脂质在消化吸收中的相互...     

类胡萝卜素肠道吸收与代谢的影响因素研究进展

类胡萝卜素是类异戊二烯单元组成的一类萜类色素,在维持眼部健康、提高免疫力等方面具有重要作用。人体不能合成这种色素,必须从膳食中摄取。人体摄入后,类胡萝卜素会经历复杂的消化吸收与代谢过程,并受到食物本身以及人体内环境等多种因素的影响。肠道是类胡萝卜素吸收、代谢最重要的场所。本文综述化合物结构、膳食因子、加工方式、包埋、转运蛋白、生物裂解酶等因素对类胡萝卜素在肠道吸收、代谢的影响,并探讨肠道菌群在其中发挥的作用,为类胡萝卜素体内的吸收与生物转化研究提供参考。     

膳食纤维经肠道微生态途径调节脂质代谢作用的研究进展

肠道菌群通过宿主与饮食交互作用在机体的脂质代谢过程中扮演着十分重要的角色。食物中广泛存在的膳食纤维及肠道菌群代谢的产物可选择性地改变肠道菌群组成,进而提高肠道短链脂肪酸水平、降低炎性因子表达水平、影响饥饿禁食诱导因子表达,从而改善机体的脂质代谢水平。膳食纤维这种通过改善肠道菌群组成来调节机体脂质代谢的生物活性作用,为预防和治疗脂质代谢紊乱等相关疾病提供了新的研究思路。本文在查阅文献的基础上,对膳食纤维经肠道微生态途径调节脂质代谢的活性作用及其机制进行了综述。     

燕麦膳食纤维对胃肠道消化吸收功能影响

一系列临床和流行病学研究表明,燕麦膳食纤维在保持肠道健康、预防慢性非传染性疾病方面具有重要作用.该文综述燕麦膳食纤维对胃肠道消化生理、在大肠发酵降解及对胃肠道形态结构影响,为进一步合理开发和应用燕麦膳食纤维提供参考.     

魔芋膳食纤维对油脂体外消化特性的影响

向油脂乳液中加入一定量魔芋膳食纤维，采用pH-stat法模拟油脂体外消化过程，考察魔芋膳食纤维对乳液在胃肠道中消化特性的影响，并研究乳液消化前后有效粒径、粒径分布、Zeta电位和微观结构的变化。结果表明，魔芋膳食纤维对乳液消化特性和消化前后理化性质产生显著性影响。随着纤维含量增加，乳液初始消化速率和最终消化程度均减小，含0.5%(质量分数)魔芋膳食纤维的乳液经胰脂肪酶消化120 min后脂肪酸释放率仅为14.84%;乳液粒径在体外消化的不同阶段逐渐增大，且同一消化阶段随纤维添加量增加而增大；肠消化后Zeta电位绝对值均大于40 mV,脂滴不稳定，发生聚集。脂肪乳液中脂质的最终消化率随体系中纤维添加量的增加而降低，该研究结果对胃肠道中脂质消化的控制及低热量功能食品的开发具有重要意义。     

乳甘油三酯的组成结构及其消化吸收和代谢特性

甘油三酯(triacylglycerols,TAGs)是膳食中最重要的脂质成分,不仅为人体提供能量同时也是多种必需脂肪酸的重要来源。甘油三酯的消化、吸收和代谢受到多种因素的影响。大量研究结果证实除脂肪酸的组成以外,甘油三酯的组成和结构对脂肪酸的吸收和代谢也有显著的影响。乳甘油三酯与其他膳食脂肪相比具有特殊的组成和结构,这些特异性使得乳甘油三酯具有许多特殊的生理和营养学功能。本文详细阐述了人乳、牛乳和山羊乳甘油三酯的结构特征,甘油三酯消化、吸收和脂肪酸代谢过程,以及甘油三酯分子内结构对其代谢的作用的影响,以期为甘油三酯代谢、营养及功能特性研究提供参考。     

蛋白质基于调节肠道微生物群的健康作用研究进展

肠道微生物群被认为是连接膳食和人体健康的重要桥梁,其生态系统的改变可能会对宿主健康造成影响。蛋白质是人类膳食营养的重要组成部分,根据来源不同,其营养特性存在差异。由于不同来源膳食蛋白的氨基酸组成结构以及消化特性的不同,为肠道中的微生物群提供了不同的代谢底物,导致微生物群的组成结构及代谢特性产生差异,进而不同程度地影响宿主健康。现有报道显示,不同来源的膳食蛋白质会以肠道菌群为介导对机体健康造成不同的影响。该文比较了不同来源蛋白质的氨基酸组成及消化利用情况,分析了其对肠道微生物群的调节作用,并分析其通过调控肠道微生物群影响健康的机理,以期更好地认识与了解膳食蛋白-肠道菌群相互作用以调节机体健康的作用差异,为科学膳食以促进健康提供有益参考。     

膳食纤维微胶囊在益生菌包埋中的应用研究进展

益生菌具有诸多健康作用，但由于在加工、储存以及人体消化过程中易受到环境因素影响，致其活力下降，无法顺利到达肠道发挥益生功能。膳食纤维具有良好的生物相容性、胶凝性和成膜性等特点，且来源广泛，作为微胶囊壁材具有巨大潜力。通过膳食纤维微胶囊技术可以为益生菌提供保护，提高其存活率、稳定性并实现在肠道中的控制释放。文章综述了膳食纤维壁材的来源、特性及其微胶囊化益生菌的制备方法，以及膳食纤维微胶囊在提高益生菌稳定性、控制释放和功能特性方面的应用，并对其在功能递送方面的发展前景进行了展望。     

药食同源生物活性物质降脂减重机制研究进展

近年来,我国居民生活水平逐步提高,营养供给能力显著增强,高脂食物摄入量陡然增加。过量的脂肪摄入会破坏机体能量代谢和物质代谢平衡、引发系统炎症,诱导肥胖、糖尿病和非酒精性脂肪肝等慢性代谢疾病的发生。基于此,美国农业部和中国营养学会分别修订了各自的膳食指南,以期通过平衡膳食改善过量脂肪摄入诱发的系统炎症和代谢紊乱。药食同源作为平衡膳食的重要组成部分,其干预缓解肥胖发生和发展的作用效果及机制备受关注。本文从药食同源生物活性物质概念出发,聚焦其降脂减重的作用效果,从降低食欲、调节脂质吸收和代谢、干预脂肪细胞的功能、影响能量消耗和脂质储存、调节肠道屏障功能和改善肠道菌群等方面综述药食同源生物活性物质降脂减重的分子机制,并对其未来研究方向进行了展望,以期为功能性食品及药品领域的开发和综合利用提供理论依据。     

食物基质及脂质分子结构对体内消化吸收的影响机制

脂质在人类饮食中占有重要地位,既可促进身体健康又可能成为疾病的来源。不同类型脂质的存在提升了食品的风味、感官评价,在人们对食物的可接受性方面起积极的作用。目前对于脂质及其应用的研究中很少考虑食物基质或脂质对人类消化吸收过程产生的影响,这些影响可能超出摄入脂肪的种类或数量的重要性。本文阐明脂质经口腔、胃及小肠的消化过程,以及脂肪酸分子在小肠内的分子吸收机制,总结脂质的组成、食物结构及蛋白质和膳食纤维等组分对脂质消化吸收的影响,为研发功能结构脂或评估天然及重组脂质对人类健康的影响提供参考。     

Food lipid oxidation under gastrointestinal digestion conditions: A review

Abstract

Unravelling the relationship between food and health requires a more in-depth knowledge of the various changes occurring in the gastrointestinal tract during digestion and which may ultimately affect the nutritional quality and safety of ingested food lipids before absorption into the bloodstream. In this context, this review deals with the oxidation process of food lipids under digestive conditions and the studies carried out on this topic using different digestion models: in vitro, in vivo or ex vivo, static or dynamic, and including one, two and/or three digestive phases (oral, gastric and duodenal). These studies have contributed to clarifying the occurrence and extent of lipid degradation under such a particular environment, many of them also highlighting the factors affecting the advance or delay of the oxidation of dietary lipids during digestion, like: food lipid content, unsaturation degree and initial oxidative status; the presence in the food bolus of compounds showing antioxidant activity (polyphenols, tocopherols…) either added or naturally present; the presence in the food bolus of proteins (including iron or not); food technological or culinary processings (salting, smoking, cooking…), among others. Likewise, the methodologies employed to study lipid oxidation under digestive conditions are also summarized and future research perspectives are discussed.     

Use of brush border membrane vesicles to simulate the human intestinal digestion

The intestine presides over a series of vital functions in the human body, among which the digestion/absorption of nutrients. Despite their major digestion role, the impact of the enzymes of the luminal intestinal surface on food components has been considered in relatively few experiments of simulated gastrointestinal digestion. In contrast, the identification of proteolitically stable peptides which survived digestion in multiphasal models that also included a step with small intestinal brush border membrane (BBM) peptidases has provided physiologically consistent results. Herein, we critically review the use of BBM enzymes to simulate the intestinal digestion of dietary polypeptides. Addressing the controversial issue of the in vitro–in vivo correspondence of the digestion models, the review emphasizes the need to establish consensus protocols to simulate the intestinal step, for instance using the BBM hydrolases at least in a selected number of cases. The factors that have limited the development of relevant models of intestinal degradation are discussed together with hints to possible alternatives, forthcoming approaches and future perspectives to reproduce the physiopathology of the human small intestine.     

基于肠道吸收机制的膳食多酚代谢研究进展

膳食多酚是植物性食物的重要成分,不仅与食品的风味和颜色等品质直接相关,还有利于人体健康。由于它们在基质释放、消化、吸收、代谢和组织分布期间发生改变,使得各种酚类化合物生物利用度有一定的差异。饮食中含量最丰富的不一定具有最佳生物利用度,多酚的吸收转化及生物利用度是多酚生物活性主要研究热点之一。本文以多酚肠道吸收机制为基点,综述了膳食多酚在胃肠道释放、吸收、代谢等过程,以期为多酚类保健食品的研发提供依据。     

胆盐理化性质及其对脂质消化的 影响机制研究进展

胆盐（BS）是胃肠道中的生物表面活性剂,在脂质消化过程中发挥着至关重要的作用。BS特殊的结构组成使之拥有不同于经典表面活性剂的理化性质,例如竞争性吸附和自组装形成胶束的行为,都参与了体内脂肪分解的过程。首先简要介绍了脂质在人体中消化吸收的过程和BS的基本性质,然后进一步阐述了BS影响脂质消化的作用机制,最后综述了近年来BS与肠道中蛋白质、脂质及其他外源食品组分相互作用的研究进展。探究BS在脂质消化中的角色,可以加深对脂质消化机制的理解,同时也可以通过调节脂质消化过程起到防治肥胖症等相关疾病的作用,还能基于BS的特殊性质开发新的载药系统。     

从农田到餐桌到营养:食物组分化学结构变化对健康效益的影响

食物富含多种化学组分,食物组分经历了加工释放与降解和体内吸收与代谢等一系列过程,最终被机体利用。随着食品化学和食品营养学科的深入发展,食物组分从农田到餐桌到人体过程中的关键变化、影响因素和调控方法得到了高度关注和广泛研究。梳理了从农田到餐桌过程中食物营养组分的体外加工和体内消化吸收阶段的变化及对人体的健康效益,介绍了食物加工、人体摄入过程中营养组分的变化(化学结构氧化降解),包括食物基质的破碎、组分的释放、体内的消化吸收,以及营养与功能组分发挥的健康功效等;分析了食物组分从农田到餐桌到人体过程中的关键影响因素,包括食物加工的方法和条件、食物的原始状态、食物的种类、食物基质性质和人体健康状态等;总结了食物从农田到餐桌到人体变化过程的营养功能强化策略,包括加工方法优化、膳食来源选择、食物形式选择、烹饪方法优化以及营养与功能组分递送系统的选择等;对未来食品营养产业的健康和可持续化发展进行了展望。     

Comparison of bovine milk fat and vegetable fat for infant formula: Implications for infant health

Fat is an important component of human milk and infant formula (IF), delivering half of the energy a baby needs. Nowadays, mostly vegetable fats are used in IFs; however, the use of bovine milk fat in formulas is currently increasing. Bovine milk fat contains a composition of fatty acids and lipid components different from those of vegetable fats. We have compared the lipid profile of human and bovine milk with infant formulas with different fat sources. Furthermore, current knowledge of how infant digestion, absorption, metabolic responses, gut immunity, microbiota and/or cognition is affected by dietary fat is reviewed. The possible opportunities and drawbacks of the application of bovine milk fat in infant nutrition are described. Future perspectives for the development of IF containing bovine milk fat and future research directions are highlighted.     

Fat digestion and absorption in spice‐pretreated rats

BACKGROUND: A few common spices are known to stimulate secretion of bile with higher amount of bile acids which play a major role in digestion and absorption of dietary lipids. It would be appropriate to verify if these spices enable efficient digestion and absorption during high‐fat intake. In this context, dietary ginger (0.05%), piperine (0.02%), capsaicin (0.015%), and curcumin (0.5%) were examined for their influence on bile secretion, digestive enzymes of pancreas and absorption of dietary fat in high‐fat (30%) fed Wistar rats for 8 weeks. RESULTS: These spices enhanced the activity of pancreatic lipase, amylase, trypsin and chymotrypsin by 22‐57%, 32‐51%, 63‐81% and 12‐38%, respectively. Dietary intake of spices along with high‐fat enhanced fat absorption. These dietary spices increased bile secretion with higher bile acid content. Stimulation of lipid mobilisation from adipose tissue was suggested by the decrease in perirenal adipose tissue weight by dietary capsaicin and piperine. This was also accompanied by prevention of the accumulation of triglyceride in liver and serum in high‐fat fed rats. Activities of key lipogenic enzymes in liver were reduced which was accompanied by an increased activity of hormone‐sensitive lipase. CONCLUSION: Thus, dietary ginger and other spice compounds enhance fat digestion and absorption in high‐fat fed situation through enhanced secretion of bile salts and a stimulation of the activity pancreatic lipase. At the same time, the energy expenditure is facilitated by these spices to prevent the accumulation of absorbed fat. Copyright © 2011 Society of Chemical Industry     

肠道吸收细胞模型研究进展及其在类胡萝卜素上的应用

膳食化合物在维持人体生理功能和预防疾病等方面至关重要,但其必须被人体高效吸收利用才能充分发挥其功能活性。肠道吸收细胞模型已成为体外模拟人体膳食化合物吸收利用及机制研究的有效手段。针对不同的膳食化合物,选取合理的肠道细胞吸收模型以及在现有细胞模型的基础上进一步改进,对于实现高效模拟人体对该膳食化合物的吸收利用具有重要意义。因此,本文概述了人体肠道上皮细胞的结构和功能,系统地综述了体外肠道细胞吸收模型研究进展,并以类胡萝卜素为代表,阐述了其肠道吸收转运机制,重点探讨了Caco-2单细胞模型和Caco-2/HT29-MTX细胞共培养模型在其吸收利用上的应用,以期为更好地利用肠道细胞吸收模型体外模拟人体对不同膳食化合物的吸收利用提供借鉴。     

Metabolic effects of dietary carbohydrates: The importance of food digestion

High blood glucose and insulin concentrations, even if within the normal range, are associated with an increased risk to develop type 2 diabetes and cardiovascular diseases. Dietary carbohydrates are the main determinants of blood glucose levels in the postprandial period; therefore, the effects of dietary carbohydrates on human health are strongly related to their rate of digestion in the small intestine. This has raised much interest on food properties able to retard carbohydrate digestion and absorption. This review is focused to examine food properties which influence carbohydrate digestion in order to predict their potential influence on health markers. Among them, it is worth to underline the role of viscosity, the physical form of the food, cooking methods and processing, the type of starch (amylose or amylopectin), the presence of anti-nutrients and the amount of fiber, fat, and proteins. In this respect particularly relevant is the type of starch present in the food, since amylose is slowly digested by intestinal α-amylases while the digestion of amylopectin is faster. However, the food component that has the strongest impact on digestion and absorption of dietary carbohydrates is dietary fiber that modulates the postprandial glucose rise by multiple mechanisms. In fact, dietary fibers may increase ingesta viscosity, thus delaying the gastric emptying time and slowing both carbohydrate digestion and the rate of glucose transport to enterocytes. In addition, they can influence the composition of the gut microbiota and induce the production of short-chain fatty acids that beneficially affect glucose and lipid metabolism. In short, the knowledge of food characteristics able to retard carbohydrate digestion and absorption in the intestine can help modify food properties with the aim of improving their functionality.