营养干预对肥胖、糖尿病机体糖脂代谢和肠道菌群的影响

肥胖、糖尿病都是代谢性疾病,会引起一系列并发症,严重危害人体健康。其病因可能是遗传和环境共同作用的结果,糖脂代谢和肠道菌群是其中的重要环境因素。糖脂代谢紊乱会引起肥胖、糖尿病,不当饮食也会导致患者的糖脂代谢紊乱加剧,通过人为改变糖类、脂肪和蛋白质的配比进行营养干预,可调节自身糖脂代谢水平以达到缓解病症和治疗的目的。此外,肥胖、糖尿病病人的肠道菌群多样性下降且功能紊乱,也是进一步维持和加剧病程的重要原因,而通过营养干预可促进肠道菌群多样性恢复及有益代谢物生成,对病症恢复起到较好作用。综述了肥胖、糖尿病与机体糖脂代谢和肠道菌群的相互作用关系,及营养干预对其的影响。     

实验动物在肠道菌群与非酒精性脂肪肝病研究中的应用

非酒精性脂肪肝病(NAFLD)是一种复杂的获得性代谢应激肝损伤疾病，NAFLD的发生发展受遗传、老龄化、生活方式、饮食、中心性肥胖相关的胰岛素抵抗、代谢综合征以及肠道菌群等相关联的并行因素的影响。近年来，人们越来越重视肠道菌群在NAFLD发病机制中的作用。肠道菌群通过多个生理过程对体内肝功能有显著影响，包括能量代谢、肥胖、糖尿病和NAFLD。动物实验提供了有力的证据，表明肠道菌群失调在肥胖症和NAFLD疾病发生发展中发挥了重要作用。本文对实验动物在肠道菌群与非酒精性脂肪肝病研究中的应用进行探讨。     

肠道菌群调控脂质代谢的分子机制

人类肠道菌群基因组又被称为“人类第二基因组” ,其在人体脂肪的分解合成过程中起到了重要的调控作用。 体内肠道菌群的失调,会引起肥胖、糖尿病等在内的代谢综合症的发生。 本文从肠道菌群通过调控在脂质代谢中 起重要作用的酶类和调控因子从而为机体提供能量、减脂和改善健康状况的研究进展方面进行了综述。     

剖析益生菌与肥胖

肥胖作为一种慢性代谢性疾病,引起的健康风险越来越受到人们的重视。过量的食物摄取、久坐的生活习惯、高糖和高脂的饮食习惯及遗传因素等均可以导致肥胖。随着消费者对健康和体型的关注度不断提高,减肥需求日益凸显。综述了肠道微生物与肥胖之间关系的最新进展,评估了肠道微生物影响宿主代谢的一些重要的分子机制如胆盐代谢、短链脂肪酸代谢和代谢性内毒素血症,并探索了益生菌调控肥胖的可能机理。此外,关于益生菌减重前景及存在的问题也有所涉及。     

膳食纤维的结构特性及其调控肠道菌群改善糖尿病的研究进展

近年来研究发现,膳食纤维(dietary fiber,DF)对肥胖、Ⅱ型糖尿病、肠易激综合征等慢性代谢疾病的治疗具有一定的作用.肠道中与人体共生的微生物群落对宿主的健康至关重要,疾病产生的同时存在肠道菌群的失调.不同的DF对肠道中微生物的调节作用不同,从而改善疾病促进人体健康.本文从DF的结构功能特性、在肠道菌群生长代谢中的作用以及肠道菌群在疾病中的角色,综述了DF通过调控肠道菌群改善糖尿病的研究进展,为DF的综合利用奠定了基础.     

脂肪因子Chemerin与运动

Chemerin是新近发现的一种由脂肪组织分泌的脂肪因子,可调节脂肪细胞的分化及代谢,并且在肥胖相关疾病中异常表达,在炎症和代谢性疾病之间具有双重作用,可能为肥胖与肥胖相关疾病之间提供一个桥梁.运动对肥胖及肥胖相关疾病可产生良好作用,是否对Chemerin产生影响研究较少.本文就Chemerin的结构特点、对肥胖相关疾病调节作用以及运动对Chemerin的影响进行论述.     

肥胖人群肠道菌群多样性研究

为了探讨肥胖人群肠道菌群多样性变化特征,招募34位志愿者,依照体重指数(中国标准)将志愿者分为四组,肥胖组、超重组、正常组、偏瘦组。获取志愿者新鲜粪便,提取肠道菌群总DNA。采用Illumina Miseq高通量测序平台,对粪便样本中所有细菌的16S rRNA V4-V5区进行DNA测序,对测序结果进行数据分析。结果发现,超重组的Chao指数显著低于正常组,Shannon指数显著低于偏瘦组,显示超重组的肠道菌群丰富度与多样性最低,正常组的肠道菌群丰富度最高,偏瘦组的肠道菌群多样性最佳;根据主成分分析与柱坐标分析发现,肥胖组的肠道菌群组成与其他三组差异较大,并且肥胖组内各样本距离较远,显示其组成也具有较大差异,提示肥胖人群的肠道微生物菌群构成不止一种模式。     

纳米塑料-重金属-塑化剂联合暴露对儿童肠道微生物菌群及代谢的影响

[目的]探究纳米塑料(NPs)、镉(Cd)和邻苯二甲酸二丁酯(DBP)污染对儿童肠道菌群多样性、氨基酸代谢及短链脂肪酸(SCFAs)含量的影响.[方法]利用16S rRNA高通量测序技术和高效液相色谱-质谱法LC-MS/MS分析NPs、Cd、DBP单一污染及纳米塑料聚丙烯(PP)、Cd、DBP复合污染对儿童肠道细菌群落及肠道微生物代谢产物中短链脂肪酸及氨基酸含量的变化.[结果]高通量检测结果显示,与对照相比,在门属水平上,单一污染的优势菌门属无明显变化,PP+Cd、PP+DBP+Cd复合污染优势菌门属水平丰富度与多样性显著下降;LC-MS/MS检测结果显示,在肠道微生物代谢产物中,经NPs与DBP暴露后,氨基酸含量呈现不同程度的下降,而Cd、PP+Cd、PP+Cd+DBP处理后,大多数氨基酸的含量显著增加;同时检测到丁酸、戊酸的含量也发生变化.[结论]与单一污染物处理相比NPs相关复合污染物暴露处理后其肠道微生物紊乱程度更强,且不同污染物处理均会影响肠道微生物的氨基酸代谢和SCFAs产量.肠道菌群与人体健康密切相关,探究肠道菌群及代谢功能在NPs、Cd、DBP影响下的变化,从肠道菌群层...     

葡萄籽原花青素对营养肥胖模型大鼠肠道菌群的影响

以高脂膳食喂养大鼠,复制营养肥胖模型,然后灌胃原花青素,采用变性梯度凝胶电泳,实时荧光定量等不依赖微生物培养的手段和多元统计分析方法,研究葡萄籽原花青素对营养肥胖模型大鼠肠道菌群生态的影响。结果表明,低剂量(100mg/(kg·体重·d))原花青素可以显著抑制大鼠肥胖,处理后大鼠肠道菌群结构与模型组分离;葡萄籽原花青素显著降低了肥胖大鼠肠道菌群中厚壁菌门的含量,提高了拟杆菌门的含量,显著降低了厚壁菌门与拟杆菌门比值;实时荧光定量检测显示,原花青素可以促进拟杆菌增殖,抑制柔嫩梭菌增殖,初步揭示出葡萄籽原花青素可能具有调节肠道菌群的功能;原花青素作用的关键微生物种属为Blautia, Bacteroides, Lactobacillus, Anaerostipes, Clostridium, Anaerofilum。     

论共生系统:肠道菌群和人类健康

共生是生物界中普遍存在的一种现象,互利共生的一个典型例子就是人类和肠道菌群.人类利用肠道菌群消化食物来获得生存所需的能量和营养,而肠道菌群则获得栖息地和营养.肠道菌群与人类相互作用形成了一种与人类健康密切相关的平衡状态,打破这种平衡状态会导致人体内的许多疾病,如肥胖、高血压、炎症性肠病、癌症等.肠道菌群参与宿主新陈代谢、机体免疫、基因表达、疾病发展和药物疗效,同时它也受饮食、抗生素、生活方式、遗传和时间点的影响.作者系统地回顾了人类与肠道菌群之间的相互作用,分析了肠道菌群在人类疾病治疗中的应用现状,描述了治疗中存在的主要问题,为肠道菌群在人类疾病治疗中的应用提供了新的思路.     

Inflammasome-mediated dysbiosis regulates progression of NAFLD and obesity

Non-alcoholic fatty liver disease (NAFLD) is the hepatic manifestation of metabolic syndrome and the leading cause of chronic liver disease in the Western world. Twenty per cent of NAFLD individuals develop chronic hepatic inflammation (non-alcoholic steatohepatitis, NASH) associated with cirrhosis, portal hypertension and hepatocellular carcinoma, yet the causes of progression from NAFLD to NASH remain obscure. Here, we show that the NLRP6 and NLRP3 inflammasomes and the effector protein IL-18 negatively regulate NAFLD/NASH progression, as well as multiple aspects of metabolic syndrome via modulation of the gut microbiota. Different mouse models reveal that inflammasome-deficiency-associated changes in the configuration of the gut microbiota are associated with exacerbated hepatic steatosis and inflammation through influx of TLR4 and TLR9 agonists into the portal circulation, leading to enhanced hepatic tumour-necrosis factor (TNF)-α expression that drives NASH progression. Furthermore, co-housing of inflammasome-deficient mice with wild-type mice results in exacerbation of hepatic steatosis and obesity. Thus, altered interactions between the gut microbiota and the host, produced by defective NLRP3 and NLRP6 inflammasome sensing, may govern the rate of progression of multiple metabolic syndrome-associated abnormalities, highlighting the central role of the microbiota in the pathogenesis of heretofore seemingly unrelated systemic auto-inflammatory and metabolic disorders.     

中老年脂质代谢紊乱患者胰岛素抵抗相关因素分析

探讨中老年不同时期的脂质代谢紊乱患者对胰岛素抵抗(IR)影响的相关因素.91例中年期、182例老年期脂质代谢紊乱患者检测空腹血糖、胰岛素、甘油三酯(TG)、胆固醇(TC)、高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C)和体质量指数(BMI),并进行相关因素分析.中年期脂质代谢紊乱患者稳态胰岛素抵抗指数(HOMA-IR)与BMI相关,老年期脂质代谢紊乱患者HOMA-IR与TG水平相关.中年期脂质代谢紊乱患者体质量因素对其胰岛素抵抗的影响较为明显,随着年龄增长,老年期TG水平对其IR的影响较为明显.     

Functional interactions between the gut microbiota and host metabolism

The link between the microbes in the human gut and the development of obesity, cardiovascular disease and metabolic syndromes, such as type 2 diabetes, is becoming clearer. However, because of the complexity of the microbial community, the functional connections are less well understood. Studies in both mice and humans are helping to show what effect the gut microbiota has on host metabolism by improving energy yield from food and modulating dietary or the host-derived compounds that alter host metabolic pathways. Through increased knowledge of the mechanisms involved in the interactions between the microbiota and its host, we will be in a better position to develop treatments for metabolic disease.     

Regulation of circadian behaviour and metabolism by synthetic REV-ERB agonists

Synchronizing rhythms of behaviour and metabolic processes is important for cardiovascular health and preventing metabolic diseases. The nuclear receptors REV-ERB-α and REV-ERB-β have an integral role in regulating the expression of core clock proteins driving rhythms in activity and metabolism. Here we describe the identification of potent synthetic REV-ERB agonists with in vivo activity. Administration of synthetic REV-ERB ligands alters circadian behaviour and the circadian pattern of core clock gene expression in the hypothalami of mice. The circadian pattern of expression of an array of metabolic genes in the liver, skeletal muscle and adipose tissue was also altered, resulting in increased energy expenditure. Treatment of diet-induced obese mice with a REV-ERB agonist decreased obesity by reducing fat mass and markedly improving dyslipidaemia and hyperglycaemia. These results indicate that synthetic REV-ERB ligands that pharmacologically target the circadian rhythm may be beneficial in the treatment of sleep disorders as well as metabolic diseases.     

Metabolic oxidation phenotypes as markers for susceptibility to lung cancer

That bronchial carcinoma is not an inevitable consequence of cigarette smoking has stimulated the search for host factors that might influence the susceptibility of the individual smoker. One plausible host factor would be a polymorphic gene controlling the metabolic oxidative activation of chemical carcinogens, giving rise to wide inter-subject variation in the generation of cancer-inducing and/or promoting species. Recently, three genetic polymorphisms of human metabolic oxidation have been demonstrated (as characterized by debrisoquine, mephenytoin and carbocysteine), with the metabolism of several substrates exhibiting the phenomenon. Debrisoquine 4-hydroxylation segregates into two human phenotypes, each comprising characteristic metabolic capability. We report here the frequency of debrisoquine 4-hydroxylation phenotypes in age-, sex- and smoking history-matched bronchial carcinoma and control patients. Cancer patients showed a preponderance of probable homozygous dominant extensive metabolizers (78.8%) with few recessive poor metabolizers (1.6%) compared with smoking controls (27.8% and 9.0% respectively). We conclude that the gene controlling debrisoquine 4-hydroxylation may be a host genetic determinant of susceptibility to lung cancer in smokers and that it represents a marker to assist in assessing individual risk.     

Abdominal obesity and metabolic syndrome

Metabolic syndrome is associated with abdominal obesity, blood lipid disorders, inflammation, insulin resistance or full-blown diabetes, and increased risk of developing cardiovascular disease. Proposed criteria for identifying patients with metabolic syndrome have contributed greatly to preventive medicine, but the value of metabolic syndrome as a scientific concept remains controversial. The presence of metabolic syndrome alone cannot predict global cardiovascular disease risk. But abdominal obesity - the most prevalent manifestation of metabolic syndrome - is a marker of 'dysfunctional adipose tissue', and is of central importance in clinical diagnosis. Better risk assessment algorithms are needed to quantify diabetes and cardiovascular disease risk on a global scale.     

Inflammation and metabolic disorders

Metabolic and immune systems are among the most fundamental requirements for survival. Many metabolic and immune response pathways or nutrient- and pathogen-sensing systems have been evolutionarily conserved throughout species. As a result, immune response and metabolic regulation are highly integrated and the proper function of each is dependent on the other. This interface can be viewed as a central homeostatic mechanism, dysfunction of which can lead to a cluster of chronic metabolic disorders, particularly obesity, type 2 diabetes and cardiovascular disease. Collectively, these diseases constitute the greatest current threat to global human health and welfare.     

Sulphide mining by the superextensile foot of symbiotic thyasirid bivalves

In a symbiotic association between an invertebrate host and chemoautotrophic bacteria, each partner has different metabolic requirements, and the host typically supplies the bacteria with necessary reduced chemicals (sulphide or methane). Some combination of anatomical, physiological and behavioural adaptations in the host often facilitates uptake and transport of reduced chemicals to the symbionts. We have studied five species of bivalve molluscs of the family Thyasiridae (that is, thyasirids) three of which harbour chemoautotrophic bacteria. Here we show that the symbiotic bivalves extend their feet to form elongated and ramifying burrows in the sediment, most probably to gain access to reduced sulphur. Closely related bivalves (including some thyasirid species) without bacterial symbionts show no comparable foot extension behaviour. The length and number of burrows formed by chemosymbiotic thyasirids are related to the concentration of hydrogen sulphide in the sediment. The burrows are formed by the foot of each bivalve, which can extend up to 30 times the length of the shell, and may be the most extreme case of animal structure elongation documented to date.     

植物挥发性次生物质对昆虫的行为调控及其机制

植物挥发性次生物质是植物在代谢过程中产生的一些短链碳氢化合物及其衍生物，在植食性昆虫的寄主植物定位、交配、寻找合适的产卵场所、取食等行为调控中起重要作用，还可调节天敌寻找寄主等行为，以及作为植物的间接防御手段和昆虫外激素的协同素。综述植物挥发性次生物质对昆虫的行为调控及其作用机理，进一步分析植物挥发性次生物质在害虫防治中的发展前景。     

Drosophila and the genetics of the internal milieu

'Homeostasis', from the Greek words for 'same' and 'steady', refers to ways in which the body acts to maintain a stable internal environment despite perturbations. Recent studies in Drosophila exemplify the conservation of regulatory mechanisms involved in metabolic homeostasis. These new findings underscore the use of Drosophila as a model for the study of various human disorders.