膳食纤维通过调节肠道微生物及其代谢产物对动脉粥样硬化的影响研究进展

膳食纤维是一种不可被消化和吸收的碳水化合物聚合物,能够通过调节肠道微生物群的生长,促进肠道微生物区系的动态平衡,进而影响肠道微生物代谢产物如脂多糖、三甲胺N-氧化物、短链脂肪酸和胆汁酸的产生,达到调节宿主生理健康的目的.动脉粥样硬化是一种慢性炎症性疾病,其发生发展与脂质代谢紊乱和炎症反应关系密切.而肠道微生物及其代谢产...     

膳食纤维生理功能及其对常量营养素吸收影响

膳食纤维对人体健康具有特殊生理功能,尤其是对慢性疾病预防作用;膳食纤维本身不能直接被机体所吸收利用,但对胃肠道功能及多种营养素吸收都有一定影响,常量营养素包括碳水化合物、蛋白质及脂类;膳食纤维对于蛋白质消化吸收影响不大,但可减少脂类和碳水化合物吸收及利用。     

青稞膳食纤维和多酚对肠道微生物的协同调节作用

以青稞面粉(hulless barley flour,HBF)、不可溶膳食纤维-多酚复合物(insoluble dietary fiber-phenolic compounds,IDF-PC)和可溶性膳食纤维-多酚复合物(soluble dietary fiber-phenolic compounds,SDF-PC)为...     

Chromium in the gastrointestinal tract of the rat

Chromium from feed intrinsically labelled with ⁵¹Cr was either fed to laboratory rats or mixed in vitro with gastrointestinal tract contents. The solubility, protein association and molecular size were measured. Chromium from intrinsically labelled feed did not appear as inorganic chromium in the gastrointestinal tract of the rat. One-fourth to one-half of the chromium in the small intestine remained in solution after centrifugation for 10 min at 12000 × g. The chromium in solution had the same exclusion volume on gel filtration chromatography throughout the gastrointestinal tract. Any protein association was quite labile. With high-fibre feed, more chromium was not soluble and probably was not available for absorption. Chromate administered with feed formed complexes with the feed and behaved similarly to intrinsically labelled feed. Chromate fed to fasted rats associated with large, possibly protein-containing, sedimentable particles in the gastrointestinal tract of the rat.     

Lactose--a potential dietary fiber. The regulation of its microecological effect in the intestinal tract. 2. The nutrient effect of lactose]

In the small intestine lactose is subjected to the hydrolytic impact of beta-galactosidase originating mainly from the mucosa. In rats about two thirds of the enzyme activity are located in the first part of the small intestine, and one third in the second one. A part of the mucosal enzyme does not remain in the mucosa. It becomes detached and can be determined in the chymus. The ratio of the transient to the resident proportion amounts to 1.8: 1 in germfree and 0.23: 1 in conventional rats. Bacterial settlement causes an increase in the mucosal mass resulting in higher total activity whereas the specific activity of the mucosal enzyme remains unchanged. Microorganisms occurring close to the small intestine mucosa take part in lactose degradation. Lactose-containing diet leads to an increase in both the bacterial and the mucosal activity, the latter one to varying degrees. Lactose concentration in the ileal chymus rises with increasing intake of lactose and decreasing protein and phosphate intake. Following a saturation kinetics the velocity of lactose hydrolysis is correlated with the lactose concentration of the diet. alpha-lactose is hydrolysed more rapidly in the small intestine of both human sucklings and rats than beta-lactose. As the results of a mathematical model show lactose mutarotation does not effect on the degree of lactose degradation in the small intestine. Depending on the intake of lactose and the food composition the rate of lactose hydrolysis amounts to: --max. 50% after small intestine perfusion in human sucklings, --max. 80% after small intestine perfusion in rats, --max. 60% in rats with ileostomata.     

复合膳食纤维改善小鼠便秘及其作用机制研究

目的? 研究复合膳食纤维对便秘小鼠的通便作用,探讨其对小鼠肠道菌群及短链脂肪酸的影响。方法? 选取BALB/c小鼠,除空白对照组外,其余小鼠通过灌胃盐酸洛哌丁胺建立便秘小鼠模型。造模成功后的小鼠随机分为模型组、聚乙二醇4000散组、复合膳食纤维低、中、高剂量组,分别给予维持饲料、聚乙二醇4000散加维持饲料、含2.5%、5%、7.5%复合膳食纤维的纯化饲料进行干预。干预14天后,通过排便实验、小肠推进实验,验证复合膳食纤维的润肠通便效果,并采集粪便检测短链脂肪酸的含量以及通过16s rDNA高通量测序分析肠道菌群组成。结果? 复合膳食纤维能降低便秘小鼠的首粒排黑便时间,增加5 h内排便数量及重量,提高粪便含水量和小肠推进率,可在一定程度上促进乙酸、丙酸、丁酸、戊酸、异丁酸、异戊酸的分泌;在门水平上,显著上调Verrucomicrobiota的相对丰度、下调Bacteroidetes相对丰度,Firmicutes的相对丰度无明显变化;在属水平上,上调有益菌Akkermansia、Faecalibaculum和Bifidobaculum的相对丰度。结论? 复合膳食纤维可以有效改善小鼠便秘,其机制可能是通过调节肠道菌群组成以及促进短链脂肪酸分泌实现的。     

黄酒对健康大鼠肥胖相关指标的影响

研究黄酒对健康大鼠肥胖指标体质量、血脂及肠道菌群的影响。 24只健康雄性SD大鼠,随机分为黄酒组、酒基对照组和空白 对照组,分别给予黄酒、15%酒基和蒸馏水,连续灌胃35 d后,测定体质量增量、总胆固醇（TC）、甘油三酯（TG）、高密度脂蛋白胆固 醇（HDL-C）、低密度脂蛋白胆固醇（LDL-C）含量及肠道菌群多样性。结果表明,黄酒对大鼠体质量增加及血脂指标没有显著影响（P≥0.05）。高通量测序结果显示,黄酒能够上调拟杆菌门并下调厚壁菌门组成比例;能够上调双歧杆菌属（Bifidobacterium）、嗜粘蛋 白-艾克曼菌属（Akkermansia muciphila）和拟杆菌属（Bacteroides）组成比例。物种α-多样性分析结果显示,黄酒对大鼠肠道菌群多样 性没有显著影响（P≥0.05）。在实验周期内,黄酒有抑制大鼠体质量增加的趋势,可能与能够调节肥胖有关的肠道菌群比例有关。     

Effects of dietary fiber on some indices of the activity of the gastrointestinal tract in rats]

Now nobody doubts of necessity and importance of inclusion of vegetative food fibres (as the separately isolated biopolymers--lignin, cellulose, gemicellulose, pectine substances; in composition of a food fibres complex or introduction last in traditional products of nutrition) in a daily human diet. Is proved by experimental researches, that the investigated kinds of food fibres are non-toxic, do not influence on internal structure, are well perceived by animals and can be recommended as the additive in a human diet.     

Research progress regarding the effect and mechanism of dietary phenolic acids for improving nonalcoholic fatty liver disease via gut microbiota

Phenolic acids (PAs), a class of small bioactive molecules widely distributed in food and mainly found as secondary plant metabolites, present significant advantages such as antioxidant activity and other health benefits. The global epidemic of nonalcoholic fatty liver disease (NAFLD) is becoming a serious public health problem. Existing studies showed that gut microbiota (GM) dysbiosis is highly associated with the occurrence and development of NAFLD. In recent years, progress has been made in the study of the relationship among PA compounds, GM, and NAFLD. PAs can regulate the composition and functions of the GM to promote human health, while GM can increase the dietary sources of PAs and improve its bioavailability. This paper discussed PAs, GM, and their interrelationship while introducing several representative dietary PA sources and examining the absorption and metabolism of PAs mediated by GM. It also summarizes the effect and mechanisms of PAs in improving and regulating NAFLD via GM and their metabolites. This helps to better evaluate the potential preventive effect of PAs on NAFLD via the regulation of GM and expands the utilization of PAs and PA-rich food resources.     

燕麦膳食纤维对食源性肥胖小鼠降脂减肥作用研究

深入研究水溶性及水不溶性燕麦膳食纤维降脂减肥作用的效果。60只昆明小鼠,饲喂高脂饲料构建肥胖模型后,分别饲喂添加低、高剂量(7.33、14.67 g·kg-1(BW)·d-1)的燕麦水溶性(SDF)水不溶性(IDF)膳食纤维的高脂饲料作为试验组,另设饲喂普通饲料和高脂饲料作为正常对照组和肥胖模型组。测定相关指标的变化。与肥胖模型组相比,肥胖小鼠在食用燕麦膳食纤维以后,Lee’s指数显著下降(P0.05),IDF效果最好;腹腔脂肪堆积显著减少(P0.05),激素敏感性脂肪酶显著升高(P0.05),同时胰岛素分泌减少促甲状腺激素分泌增加(P0.05),SDF作用效果高于IDF(P0.05);小鼠肝脏系数、肝脏总胆固醇(TC)和三酰甘油(TG)水平显著降低(P0.05),肝脏肝酯酶(HL)和脂蛋白酯酶(LPL)活性升高(P0.05),但是与正常组对照小鼠相比仍有显著差异(P0.05),SDF效果比IDF更显著。燕麦SDF和IDF都具有降脂减肥作用,存在剂量效应,但作用途径不同。     

灵芝提取物对高脂膳食大鼠脂质代谢及粪便菌群的影响

目的:探究灵芝55%醇提物对高脂膳食大鼠脂质代谢及粪便菌群的影响。方法:将24只大鼠随机分为三组,分别为空白组(基础饲料+蒸馏水,NFD)、模型组(高脂饲料+蒸馏水,HFD)和干预组(高脂饲料+150 mg/kg·d灵芝55%醇提物,GLE),每次灌胃2 mL,连续喂养8周,测量血清、肝脏的生化指标和肝脏中与脂质代谢相关mRNA的表达量,并收集第4周和第8周粪便进行菌群结构分析。结果:与模型组相比,灵芝提取物显著(p<0.05)降低血清和肝脏中的甘油三酯(TG)、胆固醇(TC)和低密度脂蛋白胆固醇(LDL-C)含量,并显著(p<0.05)提高肝脏中高密度载脂蛋白固醇(HLD-C)含量。RT-qPCR分析显示灵芝提取物极显著(p<0.01)提高过氧化物酶体增殖剂激活受体α(PPARα)的转录水平,同时抑制固醇调节元件结合蛋白(SREBP-1C)和载脂蛋白B(ApoB)的转录水平。此外,灵芝提取物能有效改善粪便菌群结构,尤其增加考拉杆菌属(Phascolsrctobacterium)、粪球菌属(Coprococcus)、萨特菌属(Sutterella)和脱硫化弧菌属(Desulfovibrio)的丰富度;并显著降低厌氧棍状菌属(Anaerotruncus)、多尔氏菌属(Dorea)、链球菌属(Streptococcus)、乳酸杆菌属(Lactobacillus)和帕拉普氏菌属(Paraprevotella)的丰富度。结论:高脂饮食诱导Wistar大鼠脂质代谢紊乱和菌群结构失调,灵芝提取物干预可改善高脂膳食大鼠脂质代谢紊乱及其肠道菌群失调。     

茶多酚调节肠道菌群及抗肥胖作用研究进展

茶是世界上最受欢迎的饮料之一,其含有丰富的茶多酚,近来,茶多酚对肠道菌群的调节作用引起了学术界的关注。肥胖可以导致心血管疾病、糖尿病、癌症等慢性疾病,因此抗肥胖物质的研究与开发也是当下的研究热点之一,茶多酚的抗肥胖作用也是其中的重要领域。本综述总结了茶多酚、肠道菌群以及肥胖三者的作用关系,并对近5年相关的非临床以及临床研究进行了总结分析。总结发现茶多酚可以调节肠道菌群组成,而肠道菌群也可以影响茶多酚的吸收与代谢。茶多酚可以通过增加益生菌的丰度以及调节能量消耗、营养物质消化吸收、脂质分解代谢和抑制脂肪细胞合成等方式发挥抗肥胖作用。目前对于茶多酚调节肠道菌群和抗肥胖作用的研究以动物模型为主,且大多实验结果证实了茶多酚的肠道菌群调节作用及抗肥胖作用,但是作用剂量尚不明确,且茶多酚剂量毒性研究不足。另外该领域临床研究不足,需要在未来进行更大样本量和更长时间的研究,以实现茶渣等副产物的高价值利用并减少肥胖相关疾病。     

膳食纤维的粉碎粒度对其食品品质及食用效果的影响研究

该研究的目标是研究膳食纤维的粉碎粒度是否对其产品 的保健功效、质量等有较大影响。实验采用粉碎粒度分别 在40-60、60-80、80-100目的精制麦麸膳食纤维,制备出 麦麸膳食纤维添加比例在/15％左右的食品,对65例习惯 性便秘患者进行了食用效果的观察实验。实验结果表明, 麦麸膳食纤维粉碎粒度在60-80目之间的食品防治便秘 的效果、口感、外观色泽均反映较好,而添加粉碎粒度在 80目以上麦麸膳食纤维的食品口感较好,但防治便秘效 果稍差;添加粉碎粒度在60目以下麦麸膳食纤维的食品 口感较粗糙,大多数被观察者难以接受。因此,麦麸膳食 纤维的粉碎粒度对其保健功效、产品质量等方面有较大 影响。     

开菲尔对高脂金黄地鼠肠道菌群的调节作用研究

利用高脂金黄地鼠模型研究开菲尔对肠道菌群的调节作用。体质量、肝脏质量、附睾脂肪质量、总胆固醇（TC）、甘油三酯（TG）、高密度脂蛋白胆固醇（HDL-C）、低密度脂蛋白胆固醇（LDL-C）测定结果表明,开菲尔能够有效控制高脂饲料引起的体质量、附睾脂肪质量增加以及LDL-C/HDL-C比值的升高（开菲尔实验组体质量、附睾脂肪质量、LDL-C/HDL-C比值分别为149.8 g、4.0 g、0.7,显著低于高脂饲料对照组的172.1 g、5.5 g、1.1）。高通量测序分析结果显示,开菲尔能够显著下调拟杆菌门、脱铁杆菌门、变形菌门和TM7菌门组成比例和上调厚壁菌门、柔膜菌门和疣微菌门比例;能够上调Akkermansia muciniphila的组成比例,并下调Alistipes indistinctus和Mucispirillum schaedleri的组成比例。因此,推断开菲尔能够调节高脂饲料引起的肠道菌群失调,抑制体质量增加和降低血脂指标。     

肠道微生物体外发酵模型研究进展及其在食品中的应用

随着分子微生态学,特别是高通量测序技术的快速发展,人们对肠道微生物的作用有了进一步认识。肠道不仅是消化吸收的场所,其微生物菌群现更被认为是一个高度特异化的\