肠上皮与肠道微生物相互作用研究进展

肠道不仅是消化和吸收的主要场所,也是机体重要的免疫器官。人类肠道中存在着超过百万亿的微生物,其在漫长的自然选择及共同进化中与宿主形成了紧密的共生关系。肠上皮是先天免疫的一个组成部分,通过各种黏膜保护屏障将肠腔内容物与机体内环境分隔开。各种肠上皮细胞相互协调维持肠道内稳态,并与肠道微生物、肠黏膜免疫系统共同形成抵御肠腔内有害抗原的第一道防线。肠上皮作为肠道微生物和肠黏膜免疫系统相互作用的枢纽,在黏膜免疫防御体系中具有重要作用,本文就肠上皮与肠道微生物之间的相互作用进行综述,旨在深入理解肠上皮,为探索肠道相关疾病的治疗提供新思路。     

乳酸菌制剂的研究进展

乳杆菌（Lactic acid bacteria）是无芽胞的厌氧或兼性厌氧的G^＋性菌,存在于人类和其他动物体内（肠道、鼻腔和阴道黏膜）以及环境中（以植物为主）的一类非常重要的微生物,对维持胃肠道的生理功能具有重要作用。自从1907年METCHNIKOFF发现乳酸菌能够抑制腐败菌生长和增强机体免疫力后,乳酸菌对机体免疫功能及其他应用受到各界的广泛关注。     

动物肠道菌群与宿主肠道免疫系统相互作用的研究进展

作为动物机体中最大的免疫器官之一,动物肠道是机体阻止外源病原体入侵的重要防线。动物肠道中定殖的微生物与宿主的营养物代谢,疾病和免疫系统发育等密切相关。该文主要综述了肠道微生物对于维持肠道屏障完整性的作用、诱导机体T、B淋巴细胞的发育和分化的分子机制及与一些代谢类疾病发生的关系等内容。尽管如此,肠道微生物与宿主免疫系统相互作用的机制还有待深入研究。随着免疫学、微生物学及分子生物学等学科的发展,对动物肠道菌群与宿主免疫系统互作机制的研究也得到快速发展,并为临床上预防和治疗人类疾病提供理论支撑。     

口腔及肠道微生物与自身免疫性疾病的研究进展CSCD

微生物在人类疾病中的作用不容忽视,这些微生物与人类共同进化,协同机体维持免疫和代谢功能。超过100万亿个共生微生物在人体各处定植,包括口腔、皮肤和胃肠道。口腔是人体微生物种类最丰富的地方之一,仅次于胃肠道。环境和功能上的差异使得口腔和肠道的常驻微生物群的组成基本不同,并在两个黏膜部位形成独特的微生态系统。新的证据表明,口腔和肠道微生物及其代谢产物为研究人类的反应机制打开了新的大门。更重要的是,它揭示了新的和潜在的治疗方法,包括粪菌移植、益生菌和益生元等,但是确切的作用机制仍不明确。作为一种有价值的治疗方法,值得我们进行更深入的研究。     

多糖对肠道功能调节作用的研究进展

肠道是机体重要的消化器官,亦是共生微生物群的主要寄居场所,在维持机体正常生命活动如免疫和内分泌功能中发挥着重要作用。 肠道功能紊乱与疾病的发生以及发展过程密切相关。近年来,多项研究结果显示,多糖具有肠道功能调节作用,包括通过作用于肠道黏膜 参与机体免疫过程、保护肠道屏障结构和功能的完整性、调节肠道菌群组成以及刺激肠道内分泌。从伴随疾病过程中的肠道功能紊乱的角度, 对多糖调节肠道功能的作用机制进行综述。     

肠道微生物与肠上皮细胞互作的免疫调节机制

人体肠道中寄居着数量众多、种类繁异的微生物,其在机体营养吸收、物质代谢以及免疫调节等方面发挥着积极作用,但肠道微生物(gut microbiota)群落结构失调或组织易位则与多种疾病的发生发展密切相关。肠上皮细胞(intestinal epithelial cells)作为机体直接接触众多肠道微生物的第一道屏障,在响应肠道微生物定植、调节肠道微生物群落结构以及维持肠黏膜屏障功能等方面发挥着至关重要的作用。本文将主要从肠黏膜免疫调控的角度,介绍肠道微生物与肠上皮细胞互作分子机制的最新研究进展。     

肠道菌群与急性肺损伤/急性呼吸窘迫综合征的关系

肠道和肺部具备相似的黏膜结构、生理功能和免疫功能。胃肠道和呼吸道黏膜菌群紊乱影响肠道疾病和急性肺损伤/急性呼吸窘迫综合征(acute lung injury/acute respiratory distress syndrome,ALI/ARDS)发展和预后。当肠道微生物群失调时会导致肠道炎症的发生,诱发肠道免疫反应并增加肠黏膜上皮的通透性,细菌及炎症因子经肠-肺轴或其他路径引发肺部疾病,致使组织器官缺血缺氧,造成肺部疾病预后不良。本文将重点关注肠道菌群失调与ALI/ARDS的关系,阐述肠道菌群失调引发的肠道和肺部慢性炎症,为肠道菌群失调引发肺部疾病的原因及其内在机制的研究提供新思路,为后续治疗提供新的线索。     

人类免疫缺陷病毒感染者免疫功能重建不全的研究进展

约20%的人类免疫缺陷病毒(human immunodeficiency virus,HIV)感染者在接受抗病毒治疗后,外周血CD4^＋ T细胞水平无法有效恢复,即免疫功能重建不全,但发生机制目前尚不明确。本文根据HIV感染者的临床和免疫学指标,分析发生免疫功能重建不全的风险因素;进一步从外周循环系统中T细胞损伤、细胞因子变化及肠道黏膜局部CD4^＋ T细胞删除等方面解析可能机制,其中肠道黏膜CD4^＋ T细胞删除可能与肠道微生物菌群诱导的细胞焦亡有关。虽然目前国际上有多项关于免疫功能重建不全患者治疗方案的临床试验,但由于缺乏一致的、有力的基础研究证据,导致疾病诊断指标缺乏,单独细胞因子给药治疗亦未取得突破性进展。因此,应深入探索免疫功能重建不全发生机制,进行大样本、长时间的前瞻性队列研究,制定免疫功能重建不全的临床与免疫学界定标准,从而为临床治疗提供科学依据。     

应激对肠道菌群的影响及机制研究进展

应激是机体受到各种因素刺激时所出现的全身非特异性反应,可对全身各个系统产生影响。肠道菌群是肠道微生态的重要组成部分,对维持机体健康发挥重要作用。应激通过影响肠道黏膜屏障功能、肠道免疫功能、胃肠道运动功能等引起肠道菌群紊乱。本文就应激对肠道菌群的影响及机制的研究进展进行综述。     

树突状细胞与肠道免疫

肠道黏膜免疫系统是肠道防御细菌和病毒感染的第一道防线,在维持肠道黏膜自稳方面发挥着重要的作用。肠道黏膜免疫系统持续不断的与来自外界的食物抗原和病原微生物及自身长期共存的肠道菌群相互作用,刺激机体对有害抗原产生免疫应答反应,诱导机体对无害抗原产生免疫耐受。树突状细胞（Dendritic cells,DCs）是目前已知的最强有力的一种专职抗原递呈细胞（Professional antigen presenting cells,APC）,     

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。     

肠黏膜屏障与肠道菌群的相互关系

摘要：人类肠道中微生物群与肠道环境相互作用以维持机体健康。肠黏膜屏障主要由黏液层、肠道菌群、肠道免疫系统和肠上皮细胞本身的完整性等构成。肠道作为直接与大量菌群接触的器官,其屏障功能在肠道健康中的作用尤为显著。肠道菌群与肠道屏障相互作用,保持肠道菌群与肠道屏障相对稳定,肠道菌群参与肠道免疫反应的建立,共同建立机体天然防御系统,在保持肠道免疫的动态平衡中具有重要作用。当两者之间的平衡被打破时,可诱发功能性胃肠病（如肠易激综合征）及免疫相关性疾病（如炎症性肠病）。本文主要阐述肠黏膜屏障与肠道菌群之间的相互关系以及与肠道屏障功能障碍相关的肠道疾病。     

Human milk oligosaccharides: the novel modulator of intestinal microbiota

Human milk, which nourishes the early infants, is a source of bioactive components for the infant growth, development and commensal formulation as well. Human milk oligosaccharide is a group of complex and diverse glycans that is apparently not absorbed in human gastrointestinal tract. Although most mammalian milk contains oligosaccharides, oligosaccharides in human milk exhibit unique features in terms of their types, amounts, sizes, and functionalities. In addition to the prevention of infectious bacteria and the development of early immune system, human milk oligosaccharides are able to facilitate the healthy intestinal microbiota. Bifidobacterial intestinal microbiota appears to be established by the unilateral interaction between milk oligosaccharides, human intestinal activity and commensals. Digestibility, membrane transportation and catabolic activity by bacteria and intestinal epithelial cells, all of which are linked to the structural of human milk oligosaccharides, are crucial in determining intestinal microbiota. [BMB Reports 2012; 45(8): 433-441].     

The role of intestinal microbiota and its metabolites in intestinal and extraintestinal organ injury induced by intestinal ischemia reperfusion injury

Intestinal ischemia/reperfusion (I/R) is a common pathophysiological process in clinical severe patients, and the effect of intestinal I/R injury on the patient''s systemic pathophysiological state is far greater than that of primary intestinal injury. In recent years, more and more evidence has shown that intestinal microbiota and its metabolites play an important role in the occurrence, development, diagnosis and treatment of intestinal I/R injury. Intestinal microbiota is regulated by host genes, immune response, diet, drugs and other factors. The metabolism and immune potential of intestinal microbiota determine its important significance in host health and diseases. Therefore, targeting the intestinal microbiota and its metabolites may be an effective therapy for the treatment of intestinal I/R injury and intestinal I/R-induced extraintestinal organ injury. This review focuses on the role of intestinal microbiota and its metabolites in intestinal I/R injury and intestinal I/R-induced extraintestinal organ injury, and summarizes the latest progress in regulating intestinal microbiota to treat intestinal I/R injury and intestinal I/R-induced extraintestinal organ injury.     

鱼类肠道微生物与宿主免疫系统相互作用研究进展

鱼类肠道中存在大量微生物,对于维持宿主健康具有重要作用。鱼类免疫系统能够监视并调控肠道微生物组成,维持肠道菌群稳态。同时,鱼类肠道共生微生物调节鱼类免疫系统,抑制病原微生物的过度增殖,保证宿主的健康。本文回顾了鱼类肠道微生物与宿主免疫系统相互作用的研究进展,重点介绍了宿主免疫系统识别肠道微生物、塑造肠道菌群以及益生菌对宿主免疫和肠道菌群的调控等,提出了理想的益生菌应该来自动物自身胃肠道,生产中应谨慎选用非宿主来源的益生菌,以期为推动鱼类肠道功能微生物开发和应用提供理论支撑。     

The potential for probiotic manipulation of the gastrointestinal microbiome

Multiple internal and external sites of the healthy human body are colonized by a diversity of symbiotic microbes. The microbial assemblages found in the intestine represent some of the most dense and diverse of these human-associated ecosystems. Unsurprisingly, the enteric microbiome, that is the totality of microbes, their combined genomes, and their interactions with the human body, has a profound impact on physiological aspects of mammalian function, not least, host immune response. Lack of early-life exposure to certain microbes, or shifts in the composition of the gastrointestinal microbiome have been linked to the development and progression of several intestinal and extra-intestinal diseases, including childhood asthma development and inflammatory bowel disease. Modulating microbial exposure through probiotic supplementation represents a long-held strategy towards ameliorating disease via intestinal microbial community restructuring. This field has experienced somewhat of a resurgence over the past few years, primarily due to the exponential increase in human microbiome studies and a growing appreciation of our dependence on resident microbiota to modulate human health. This review aims to review recent regulatory aspects related to probiotics in food. It also summarizes what is known to date with respect to human gastrointestinal microbiota - the niche which has been most extensively studied in the human system - and the evidence for probiotic supplementation as a viable therapeutic strategy for modulating this consortium.     

昆虫肠道防御及微生物稳态维持机制

在长期的进化过程中,昆虫形成了独特的肠道防御系统,主要由物理屏障和免疫系统共同作用来抵御外来微生物的入侵。如大部分后生动物一样,昆虫肠道上皮细胞无时无刻不与微生物接触,其种类从有益的共生菌、随食物进入的微生物到影响宿主生命的病原菌。在这样一种复杂的环境中,为了实现防御肠道病原微生物的同时又能维持共生微生物稳定的目的,宿主肠道上皮细胞必须在免疫应激和免疫耐受之间保持一种稳态平衡。Duox-ROS免疫系统和免疫缺陷(immune deficiency,Imd)信号通路作为肠道免疫反应的基本途径,必然参与调节此过程。本文从昆虫肠道防御组成、肠道免疫信号通路作用分子机制以及肠道免疫系统在肠道微生物群落稳态维持中的作用的最新研究进展进行综述。     

Celiac disease microbiota and its applications

Intestinal microbiota plays an important role in maintaining the overall health of an individual. It can be affected by diet but also inflammation of the intestine due to various causes. In the last decade, particular attention has been paid to the study of the interaction between mucosal cells and intestinal microbiota, and to the host immune response to change in community structure. Here, we review the most significant studies on human microbiota in patients with celiac disease, and also the potential biotechnological use of microorganisms for the production of gluten-free products.     

Antibiotics as growth promotants: mode of action

Recent concerns about the use of growth-promoting antibiotics in pig diets have renewed interest in the immunologic and growth-regulating functions of the gastrointestinal (GI) tract. The numerically dense and metabolically active microbiota ofthe pig GI tract represents a key focal point for such questions. The intestinal microbiota is viewed typically as a beneficial entity for the host. Intestinal bacteria provide both nutritional and defensive functions for their host. However, the host animal invests substantially in defensive efforts to first sequester gut microbes away from the epithelial surface, and second to quickly mount immune responses against those organisms that breach epithelial defenses. The impact of host responses to gut bacteria and their metabolic activities require special consideration when viewed in the context of pig production in which efficiency of animal growth is a primary objective. Here, we summarize the working hypothesis that antibiotics improve the efficiency of animal growth via their inhibition of the normal microbiota, leading to increased nutrient utilization and a reduction in the maintenance costs ofthe GI system. In addition, novel molecular ecology techniques are described that can serve as tools to uncover the relationship between intestinal microbiology and growth efficiency.     

母婴间菌群传递的研究进展

肠道菌群的结构对婴儿肠道系统发育及免疫系统构建具有重要的影响,研究表明最初的婴儿肠道菌群在母亲子宫内就已经存在并受分娩方式和喂养方式的影响。本研究从母亲怀孕、分娩、喂养三个阶段综述母婴间的菌群传递,为母婴间菌群传递机制及婴儿肠道菌群对其免疫系统构建的影响提供一定的理论依据。