鸡肠道菌群和短链脂肪酸相互关系的研究进展

肠道是动物机体重要的消化和营养吸收器官。肠道菌群决定肠道健康,进而影响机体健康。近年来关于肠道菌群的研究越来越多,且肠道菌群酵解底物产生的短链脂肪酸也备受人们关注。短链脂肪酸主要包括乙酸、丙酸、丁酸等及其盐类。在对肠道功效方面,短链脂肪酸发挥着重要作用,如氧化供能、维持水电解质平衡、调节免疫、抗病原微生物及抗炎、调节肠道菌群平衡、改善肠道功能等。因此,本文根据近年来国内外相关研究报道,综述了鸡肠道不同种类、含量的菌群对短链脂肪酸来源和吸收的影响;不同种类、含量和制剂形态的短链脂肪酸对肠道菌群影响的研究进展,为更好地了解鸡肠道菌群和短链脂肪酸的相互关系和提高禽类养殖水平提供理论指导。     

短链脂肪酸对肠道动力影响的研究进展

人体的肠道不仅仅是消化吸收场所,也是大量微生物生存的家园。肠道作为人体最大的“储菌库”,其多种生理功能离不开复杂多变的肠道菌群和菌群代谢物(如短链脂肪酸等)的参与。短链脂肪酸是肠道菌群发酵膳食纤维产生的一类重要的信号分子,研究发现短链脂肪酸除参与维持人体肠道黏膜免疫屏障、调节体液及电解质平衡以及为肠上皮细胞提供能量外,还与肠道动力调节有关。本文就短链脂肪酸在肠道动力调节中的作用进行综述,旨在深入理解短链脂肪酸与肠道的互作关系,维持肠道的机械屏障,从而为探索肠道相关动力疾病的治疗提供新思路。     

短链脂肪酸在宿主能量代谢方面的调节作用

肠道菌群数量庞大,对宿主多种生理活动具有重要调节作用。现有研究发现,肠道菌群主要通过调节其产生的不同代谢产物,参与宿主物质代谢反应,改变能量代谢水平,影响机体炎症反应。在诸多代谢产物中,短链脂肪酸(醋酸盐、丙酸盐、丁酸盐等)具有重要调节作用,对机体代谢功能方面具有深远影响。本文结合国内外相关研究文献,综述了短链脂肪酸在调节机体能量代谢方面的相关研究,以期为进一步阐明其在机体能量代谢方面的作用提供科学依据。     

衰弱症干预的新角度：营养-肠道菌群-衰弱轴

在全球人口老龄化背景下,衰弱症作为老年医学重要的多维概念,其早期诊断和干预已成为研究者关注的主要方向。能量和营养的低摄入在推动衰弱症进展中的作用不容忽视。肠道菌群通过双向调节宿主和肠菌的营养代谢、信号传导,以及对宿主多种器官的直接生物化学作用,不仅参与代谢疾病的发病机制,而且帮助营养策略发挥干预作用。本综述从骨骼肌和免疫角度总结了肠道菌群和食源性代谢物参与营养-衰弱相互作用的文献进展。现有文献提示短链脂肪酸和氨基酸等食源性肠道菌群代谢物作为宿主受体的配体参与调节肌肉、认知和免疫功能,进而影响宿主的衰弱进程,即支持“营养-肠道菌群-衰弱轴”的存在。随着肠道菌谱分析和代谢组学等技术在该领域的深入应用,营养-肠道菌群将为衰弱症的早期发现和干预提供新颖、经济和有效的个体化手段。     

microRNA 对宿主和肠道微生物互作的调控

摘要:肠道内环境是宿主和肠道微生物菌群互作的结果,肠道菌群一方面通过抗原物质调节肠道组织的免疫稳定,另一方面,肠道菌群参与糖、脂、蛋白质代谢,产生的代谢产物能够调控细菌营养代谢、群体结构和肠道组织的营养吸收等。microRNA是宿主细胞内调控基因表达的重要因子,肠道微生物菌群不仅调控宿主mRNA的转录,同时也影响某些基因的转录后修饰。研究表明,肠道菌群通过与宿主肠道组织互作,调节肠上皮组织内某些参与炎症应答和屏障功能的microRNA 的表达。本文介绍了肠道微生物与宿主互作的基本内容,对microRNA在肠道微生物与宿主互作和肠道健康中的调节进行综述。     

生物钟与肠道菌群调控哺乳动物能量代谢研究进展

生物钟作为哺乳动物进化过程中产生的一种适应机体内外环境昼夜变化的内在机制,控制着机体的睡眠-觉醒及进食等生理活动,使生物体在每个昼夜周期的能量需求和营养供给呈现出与环境相适应的节律性变化。哺乳动物的肝脏、骨骼肌、胰腺、心血管等组织的葡萄糖代谢、脂质代谢和激素分泌等都受到生物钟的调控。作为宿主特殊的“器官”,肠道菌群在共同进化过程中与宿主微环境(组织、细胞、代谢产物)构成了一个微生态系统,在宿主对营养物质的消化和吸收过程中发挥重要作用。近年来的一些研究证据表明,肠道菌群的构成、数量、定植以及功能活动均具有显著的昼夜节律性变化,而这与生物钟调控下的各种生理功能变化是密切相关的。此外,有研究发现肠道菌群可通过分解宿主无法消化的膳食纤维等营养物质产生短链脂肪酸等代谢产物,部分代谢产物具有调节宿主生物钟并影响代谢的功能。本文将重点阐述生物钟与肠道菌群的互作及其对哺乳动物能量代谢的影响,以期为代谢性疾病的预防和治疗提供新的线索和思路。     

肠道菌群代谢产物在鼠伤寒沙门菌感染中的作用研究进展

人和动物肠道内生存着多种多样的微生物群体,它们与宿主共同进化,对宿主的健康至关重要。肠道菌群可以发酵宿主难以消化的复杂碳水化合物,为宿主肠道细胞提供能量,同时其代谢产物对肠道病原菌沙门菌的感染产生着重要影响。正常情况下,肠道菌群代谢产物如丁酸与丙酸可以抑制沙门菌在肠道中的定植或者毒力基因的表达,而在肠道菌群受到扰乱时,其代谢的琥珀酸盐和1,2-丙二醇等物质却能促进沙门菌增殖。近年来,越来越多的研究揭示了肠道菌群代谢产物对沙门菌感染的影响。本综述通过总结近年来关于鼠伤寒沙门菌入侵时肠道菌群代谢产物改变的研究,综合阐述了肠道菌群代谢产物影响沙门菌感染的机制。     

2型糖尿病肠道菌群研究进展

2型糖尿病是一种常见的慢性消耗性疾病,其发病机制十分复杂,流行病学研究表明,肥胖、高热量饮食、体力活动不足及年龄增大是2型糖尿病最主要的环境因素。它是一种以胰岛素抵抗和胰岛素分泌不足为特征的代谢性疾病。肠道菌群作为进入人体的一个重要环境因素,肠道微生物的菌群变化影响宿主能量物质的吸收,调节肠道的分泌功能和非特异性免疫功能,从营养、代谢、疾病等各方面与我们生命活动相关。肠道菌群已成为我们身体的一部分,影响宿主的免疫,在肥胖、糖尿病、代谢综合征等疾病中都具有非常重要的作用。     

肠道微生物及其代谢产物与宿主脂质代谢研究进展

近年来,肠道微生物与宿主脂质代谢研究受到国内外的广泛关注.首先,肠道微生物多样性和组成在脂肪代谢紊乱动物模型、肥胖患者中均发生显著改变,而利用粪菌移植、益生菌以及营养干预重塑肠道菌群结构可以调控宿主脂质代谢.本文重点介绍了肠道微生物与宿主脂代谢的联系,并从短链脂肪酸、胆汁酸、氨基酸、内毒素和微生物节律等方面探讨了肠道微...     

膳食脂肪对肠道微生物的影响及 宿主代谢调控的研究进展

膳食脂肪作为人体重要的营养物质之一,为人体提供能量及营养。不同种类的膳食脂肪对宿主肠道微生物的组成和数量的影响有着明显的差异。同时肠道微生物又能参与宿主的代谢调控以及影响肠道屏障功能等。过多的摄入富含饱和脂肪酸的膳食脂肪会引起肠道中厚壁菌门、变形菌门、梭菌属等的增加,从而影响宿主代谢过程中的胆汁酸等信号分子改变,导致肠道通透性的增加和系统炎症。富含n-3多不饱和脂肪酸的膳食脂肪会引起肠道中双歧杆菌和乳杆菌的增加,从而影响宿主代谢过程中的短链脂肪酸的水平,某些短链脂肪酸能够调控宿主的胰岛素分泌以及炎症因子的表达。本文综述了膳食脂肪的种类、肠道微生态和宿主代谢调控之间的相互作用及其可能的作用机制,为深入了解饮食、肠道微生态、宿主健康三者之间的关系提供了依据。     

海洋鱼类肠道微生物研究进展及应用前景

肠道微生物在动物体内数量庞大、结构复杂,在宿主生长发育过程中发挥着重要作用.淡水鱼类肠道微生物的研究主要集中于其对鱼类生长代谢、营养吸收及免疫调节等方面的影响,海洋鱼类则研究相对较少,且多集中于肠道微生物多样性及其变动影响因素分析.本文在归纳总结鱼类肠道微生物功能及其研究方法的基础上,着重分析肠道微生物在海洋鱼类生长发...     

环境胁迫下内生菌与宿主代谢相互作用研究进展

植物体内成分是实时反映其生理状态的最直接指标,是其遭受生物或非生物胁迫应激状态的体现,微生物与植物的共生抗逆亦由代谢的重置与调控得以实现.内生菌可以自身细胞功能或代谢产物调控宿主代谢,其自身可产生独特的、显著区别于宿主的代谢成分参与抗逆;而宿主内环境的长期“驯化”亦可改变内生菌的表型和代谢.较全面地分析了植物与微生物共...     

瘤胃微生物与宿主互作及其日粮调控研究进展

瘤胃微生物与宿主间存在互作关系,宿主动物遗传信息影响瘤胃微生物,而瘤胃微生物变化也同样受到日粮原料、营养水平以及外源添加物质的调控。近年来,通过多组学技术分析瘤胃微生物与宿主关系及其内在机制已成为研究热点。综述了瘤胃微生物与宿主关系及受日粮调控作用研究进展,具体介绍了瘤胃微生物与宿主基因组关系,瘤胃微生物与动物生产性能关系,以及在日粮配置、益生菌益生元和植物次生代谢物添加等条件下对瘤胃微生物的影响;并对瘤胃微生物研究的发展趋势和应用前景进行了展望。     

肠道微生物对寿命的影响及其机制*

延长健康寿命的跨度对每个人都有重要意义,百岁老人存在独特的肠道菌群特征,肠道微生物群是许多年龄相关变化的核心,菌群特征以及菌群基因组成改变都能影响机体寿命。一些饮食和药物要发挥延寿效果也离不开微生物的参与,微生物具有重要的介导和转化作用,益生菌和粪便移植等措施在动物模型中已被明确可以影响机体寿命。越来越多的研究表明微生物不仅能产生小分子化合物促进健康寿命跨度的增加乃至延长个体寿命如γ-氨基丁酸、荚膜异多糖酸,还能影响宿主的生物合成代谢如5-羟色胺,甚至间接参与宿主信号通路的调控。目前对于这些微生物的生物学功能以及对宿主寿命的影响还没有系统的总结,对肠道微生物影响寿命的证据以及生理机制进行综述,为改善老年期健康状况的干预措施提供参考。     

动物宿主——肠道微生物代谢轴研究进展

肠道中栖息着数量庞大且复杂多样的微生物菌群,在维持宿主肠道微环境稳态中发挥重要作用。微生物菌群可以利用宿主肠道的营养素,发酵产生代谢产物,与宿主机体形成宿主—微生物代谢轴(host-microbe metabolic axis)。该代谢轴既能影响营养素吸收和能量代谢,又可调控宿主各项生理过程。本文主要阐述宿主-肠道微生物代谢轴的概念、肠-肝轴、肠-脑轴、肠道微生物与宿主肠道代谢轴的互作以及对机体健康的影响。     

The role of short-chain fatty acids in the interplay between diet,gut microbiota,and host energy metabolism

Short-chain fatty acids (SCFAs), the end products of fermentation of dietary fibers by the anaerobic intestinal microbiota, have been shown to exert multiple beneficial effects on mammalian energy metabolism. The mechanisms underlying these effects are the subject of intensive research and encompass the complex interplay between diet, gut microbiota, and host energy metabolism. This review summarizes the role of SCFAs in host energy metabolism, starting from the production by the gut microbiota to the uptake by the host and ending with the effects on host metabolism. There are interesting leads on the underlying molecular mechanisms, but there are also many apparently contradictory results. A coherent understanding of the multilevel network in which SCFAs exert their effects is hampered by the lack of quantitative data on actual fluxes of SCFAs and metabolic processes regulated by SCFAs. In this review we address questions that, when answered, will bring us a great step forward in elucidating the role of SCFAs in mammalian energy metabolism.     

The intestinal microbiome associated with lipid metabolism and obesity in humans and animals

Intestinal microbiota is considered to play an integral role in maintaining health of host by modulating several physiological functions including nutrition, metabolism and immunity. Accumulated data from human and animal studies indicate that intestinal microbes can affect lipid metabolism in host through various direct and indirect biological mechanisms. These mechanisms include the production of various signalling molecules by the intestinal microbiome, which exert a strong effect on lipid metabolism, bile secretion in the liver, reverse transport of cholesterol and energy expenditure and insulin sensitivity in peripheral tissues. This review discusses the findings of recent studies suggesting an emerging role of intestinal microbiota and its metabolites in regulating lipid metabolism and the association of intestinal microbiota with obesity. Additionally, we discuss the controversies and challenges in this research area. However, intestinal micro-organisms are also affected by some external factors, which in turn influence the regulation of microbial lipid metabolism. Therefore, we also discuss the effects of probiotics, prebiotics, diet structure, exercise and other factors on intestinal microbiological changes and lipid metabolism regulation.     

Fermentation trip: amazing microbes,amazing metabolisms

Fermentation has been applied to many areas of human life, including industrial production, sewage treatment, and environment management. By understanding the process and mechanism of fermentation, more comprehensive and profound cognition of the fermentation may be established to lay a foundation for our further research. In this review, we present a brief summary of recent research about fermentation and microorganisms in different territories, including foods, environment, and human health. According to the growth characteristics of different stages of microorganisms, we introduced a series of metabolic changes, fermentation mechanism, and regulation methods and how the enzymes were transported out of the cell. With further understanding and utilization of microorganisms, food can produce better flavor, nutrition, and functional metabolites through fermentation. Fermentation is also used in other industries, such as wastewater and garbage disposal, environment, and soil management. The human gut flora, in particular, has begun to receive more attention. The profound influence of microorganism on human health cannot to be underestimated. It has become a hot research area in recent years. We can get the metabolites we want by controlling the rate of fermentation and regulate the direction of fermentation. As one of the important components of modern biotechnology, fermentation engineering has been widely used in areas including food, pharmaceutical, energy, chemical industries, and environmental protection. The development of genetic engineering has brought new vitality to fermentation engineering. The application of modernization, automation and artificial intelligence technology also opens up new space for fermentation engineering. In addition, research on the understanding and regulation of metabolic mechanism has further developed the fermentation function of microorganisms.     

烟叶微生物及其在烟叶发酵和醇化中的作用研究进展

微生物在烟叶发酵和醇化过程中具有十分重要的作用。本文综述了烟叶微生物概况及其在烟叶发酵和醇化中的应用和研究进展。主要介绍了烟叶微生物的区系划分、烟叶发酵和醇化过程中微生物动态变化以及外源添加微生物的应用方法。阐述了微生物在缩短烟叶发酵和醇化周期、改善烟叶品质、降低烟叶有害物质和提高烟叶安全性等方面的研究应用成果。最后,对该领域今后的研究方向提出了展望。     

Elucidation of the metabolic fate of glucose in the filamentous fungus Trichoderma reesei using expressed sequence tag (EST) analysis and cDNA microarrays

Despite the intense interest in the metabolic regulation and evolution of the ATP-producing pathways, the long standing question of why most multicellular microorganisms metabolize glucose by respiration rather than fermentation remains unanswered. One such microorganism is the cellulolytic fungus Trichoderma reesei (Hypocrea jecorina). Using EST analysis and cDNA microarrays, we find that in T. reesei expression of the genes encoding the enzymes of the tricarboxylic acid cycle and the proteins of the electron transport chain is programmed in a way that favors the oxidation of pyruvate via the tricarboxylic acid cycle rather than its reduction to ethanol by fermentation. Moreover, the results indicate that acetaldehyde may be channeled into acetate rather than ethanol, thus preventing the regeneration of NAD(+), a pivotal product required for anaerobic metabolism. The studies also point out that the regulatory machinery controlled by glucose was most probably the target of evolutionary pressure that directed the flow of metabolites into respiratory metabolism rather than fermentation. This finding has significant implications for the development of metabolically engineered cellulolytic microorganisms for fuel production from cellulose biomass.