高原肠道菌群与动脉粥样硬化性缺血性脑卒中的相关性研究

肠道微生物组是人体内最大的微生物库,在神经发育、衰老和脑部疾病中发挥着重要作用。近年来,肠道菌群越与缺血性脑卒中的关系也成为脑卒中研究者的热门研究课题。在正常情况下,肠道微生物群与人体和外部环境保持平衡状态,然而在高原地区,可能因缺氧导致消化功能紊乱致使细菌移位和肠道微生物群失衡。本文就动脉粥样硬化性缺血性脑卒中与高原肠道菌群的相关性研究进行综述,同时对其治疗前景进行展望。     

肠道微生物群在妊娠期肥胖及糖尿病中的作用

肠道微生物群是定植在人体肠道内的全部微生物及其基因的统称。近年来研究发现,肠道微生物群的改变与妊娠期肥胖及糖尿病的发生、发展密切相关。肠道微生物群的改变可能通过影响某些代谢机制影响相关疾病的发生、发展,其具体的分子生物学机制尚不明确。文章对肠道微生物群在妊娠期肥胖及糖尿病中的作用进行综述。     

肠道菌群与机体疾病及慢性肾脏疾病的研究进展

健康人体中的肠道菌群与机体免疫状态相关,肠道菌群失衡可引发多种疾病。该文从膳食对肠道菌群的影响、肠道菌群与机体疾病、肠道菌群失衡与慢性肾脏疾病等几个方面进行综述。     

肠道微生物与老年人认知功能障碍

肠道微生物参与人体众多生理代谢活动,具有十分重要的生理意义,肠道微生物的组成与人体的健康状况密切相关。以往认为,由于血脑屏障和肠道屏障的存在,肠道微生物对大脑的影响很小。近年来越来越多的研究显示,肠道微生物可通过多种途径作用于中枢神经系统。不仅影响神经系统的正常发育,还参与了许多神经精神疾病的发病过程,如焦虑、抑郁症、孤独症、精神分裂症等,通过给患者服用益生菌等微生态制剂可改善患者的临床症状;更重要的进展提示,肠道微生物与认知障碍可能有重要关系。本文就肠道微生物和人体中枢神经系统之间的相互作用、肠道菌群在老年期的变化,以及肠道微生物在认知障碍中的作用和相关治疗进展做一综述。     

肠道菌群及微生态调节剂在儿科临床中的作用

人与其寄居的微生物群构成人体的微生态系统。这些微生物群对人体有着极其重要的生理作用，人体的健康依赖于二者之间的平衡，如果平衡失调将导致疾病发生。肠道菌群占人体总微生物量的78．67％．因此，它与人体的健康有着密切的关系。     

肠道微生物菌群与慢性肾脏病的研究进展

正肠道微生物群与宿主一直互利共存的,并在宿主的新陈代谢中扮演着重要角色。正常肠道微生物群以营养、代谢、生理和免疫功能等多方面影响着人体健康,而肠道微生物群菌群失调参与多种疾病的发生发展,如肥胖、2型糖尿病、炎症性肠病、心血管疾病等。目前越来越多的证据表明,肠道菌群失调参与了导致慢性肾脏病(chronic kidney disease,CKD)的进展以及并发症的发生,而补充益生菌可能对CKD患者具有潜在的收益,本文就肠道微生物菌群与CKD的关系,综述如下。1肠道微生物群     

益生菌的免疫效应

人体肠道内存在数量庞大、结构复杂的正常菌群，肠壁中存在数量众多的淋巴细胞，机体通过肠道黏膜与肠道中微生物相互作用，这些微生物包括定植于肠道中的以及机体摄入的。机体以肠黏膜为界，两者相互作用，相互制约，处于动态平衡状态。正常肠道菌群在促进免疫系统发育，维持正常免疫功能，协同拮抗病原菌入侵方面发挥重要作用。     

菌群微生态在ICU多重耐药菌防治中的研究进展

微生物广泛存在于人体和周围环境中.自出生起,婴儿接受了来自母体的大部分菌群,并在后天的生长发育中逐渐形成自身的菌群结构.人体中的微生物构成了复杂的微生态环境,其中肠道中存在着大约1014个微生物,包括细菌、古菌和病毒等,统称为肠道菌群,主要包括拟杆菌门、厚壁菌门、放线菌门和变形菌门[1].目前微生物组研究日益深入,微生...     

肠道菌群紊乱与带状疱疹发病相关性研究进展

近年来的许多研究提示,肠道内复杂的微生物群落和人体的免疫系统间存在着极为密切的关系。免疫系统发挥正常的功能及建立免疫的稳态与肠道菌群的作用密不可分。一旦出现肠道菌群的紊乱势必会导致机体免疫功能的低下,而带状疱疹的发病与免疫低下直接相关,那么肠道菌群的紊乱与带状疱疹的发病是否有一定的关联呢,本文将对这一问题进行一个系统性综述。     

人体肠道微生物组与疾病研究:现状、机遇与挑战

微生物组是人体的第二基因组,能够决定人的健康状态。微生物组研究促进了人类对微生物群体与人体、生态环境关系的新认识。对人体肠道微生物组的组成和功能进行系统研究,解析相关核心菌群的互作关系和调控机制,将为解决人类面临的健康问题带来革命性的理论创新,由此产生颠覆性的技术革新,有望为微生物组研究提供更好的解决方案。     

肠道菌群与人体免疫系统相关性研究方兴未艾

肠道菌群作为人体中数量众多的异种成分, 与人体免疫系统有着复杂的双向作用。一方面, 菌群和人体的共生依赖于免疫耐受形成; 另一方面肠道相关免疫组织的发育和免疫细胞的激活亦受到源自菌群的异源性信号密切调控。因此, 肠道菌群对于正常免疫系统的建立至关重要, 反之, 免疫系统的改变亦可能造成肠道菌群紊乱, 二者之间的相互作用发生异常可能影响局部乃至全身免疫系统, 进而参与系统性炎症性疾病、自身免疫性疾病以及肿瘤的发病机制。有临床研究表明, 益生菌补充和健康人粪菌移植联合传统免疫治疗能够提高耐药患者的疗效, 提示肠道菌群可能是潜在的重要治疗靶点, 因此了解肠道菌群在人体免疫中的作用非常重要。     

Gut microbiota and COVID-19: An intriguing pediatric perspective

Gastrointestinal (GI) involvement has been reported in approximately 50% of patients with coronavirus disease 2019 (COVID-19), which is due to the pathogenic role of inflammation and the intestinal function of the angiotensin-converting enzyme 2 and its receptor. Accumulating adult data has pointed out that gut dysbiosis might occur in these patients with a potential impact on the severity of the disease, however the role of gut microbiota in susceptibility and severity of COVID-19 disease in children is still poorly known. During the last decades, the crosstalk between gut and lung has been largely recognized resulting in the concept of “gut-lung axis” as a central player in modulating the development of several diseases. Both organs are involved in the common mucosal immune system (including bronchus-associated and gut-associated lymphoid tissues) and their homeostasis is crucial for human health. In this framework, it has been found that the role of GI dysbiosis is affecting the homeostasis of the gut-liver axis. Of note, a gut microbiome imbalance has been linked to COVID-19 severity in adult subjects, but it remains to be clarified. Based on the increased risk of inflammatory diseases in children with COVID-19, the potential correlation between gut microbiota dysfunction and COVID-19 needs to be studied in this population. We aimed to summarize the most recent evidence on this striking aspect of COVID-19 in childhood.     

Familial transmission rather than defective innate immunity shapes the distinct intestinal microbiota of TLR-deficient mice

The intestinal microbiota contributes to the development of the immune system, and conversely, the immune system influences the composition of the microbiota. Toll-like receptors (TLRs) in the gut recognize bacterial ligands. Although TLR signaling represents a major arm of the innate immune system, the extent to which TLRs influence the composition of the intestinal microbiota remains unclear. We performed deep 16S ribosomal RNA sequencing to characterize the complex bacterial populations inhabiting the ileum and cecum of TLR- and MyD88-deficient mice. The microbiota of MyD88- and TLR-deficient mouse colonies differed markedly, with each colony harboring distinct and distinguishable bacterial populations in the small and large intestine. Comparison of MyD88-, TLR2-, TLR4-, TLR5-, and TLR9-deficient mice and their respective wild-type (WT) littermates demonstrated that the impact of TLR deficiency on the composition of the intestinal microbiota is minimal under homeostatic conditions and after recovery from antibiotic treatment. Thus, differences between TLR-deficient mouse colonies reflected long-term divergence of the microbiota after extended husbandry in isolation from each other. Long-term breeding of isolated mouse colonies results in changes of the intestinal microbiota that are communicated to offspring by maternal transmission, which account for marked compositional differences between WT and mutant mouse strains.     

肺-肠轴：儿童呼吸道感染与肠道微生态的相关性

肠道菌群是作为维持器官微环境的重要调节剂,由肠道-重要器官轴发挥作用。多项研究表明,肠道菌群及其代谢产物可有效预防和治疗呼吸系统疾病。然而,由于儿童肠道菌群的组成与成年人不同,并且其免疫系统正处于发育过程中,因此关于儿童肠道菌群与呼吸道感染之间相互作用的研究仍然很少。该文从“肺-肠轴”角度介绍了呼吸道感染儿童肠道菌群的变化,并分析了儿童肠道菌群与免疫功能和呼吸道感染之间的相关性,期望能为临床从肠道菌群入手治疗儿童呼吸道感染提供参考。     

Le microbiote intestinal: composition et fonctions

Hundreds of species compose the human gut microbiota, which reaches its highest density in the large bowel (10¹¹ bacteria per gram). If this species profile is specific to a given individual, three phyla (Firmicutes, Bacteroidetes, Actinobacteria) invariably dominate the adult human gut microbiota. This microbiota is globally stable in time and return to its initial status following a perturbation. It also exerts various functions, in particular metabolic functions, which are essential for maintaining host??s health. This microbial community is indeed able to convert a large variety of substrates (including sugars, proteins, and lipids) leading to the production of a diversity of metabolites. Most of these metabolites could beneficially affect host??s health. In addition, comparisons between germfree and conventional animals revealed the influence of the gut microbiota on the development and maturation of the immune system, the intestinal physiology, or the regulation of fat storage.     

Mitochondrial dysfunction in inflammatory bowel disease alters intestinal epithelial metabolism of hepatic acylcarnitines

As the interface between the gut microbiota and the mucosal immune system, there has been great interest in the maintenance of colonic epithelial integrity through mitochondrial oxidation of butyrate, a short-chain fatty acid produced by the gut microbiota. Herein, we showed that the intestinal epithelium could also oxidize long-chain fatty acids, and that luminally delivered acylcarnitines in bile could be consumed via apical absorption by the intestinal epithelium, resulting in mitochondrial oxidation. Finally, intestinal inflammation led to mitochondrial dysfunction in the apical domain of the surface epithelium that may reduce the consumption of fatty acids, contributing to higher concentrations of fecal acylcarnitines in murine Citrobacter rodentium–induced colitis and human inflammatory bowel disease. These results emphasized the importance of both the gut microbiota and the liver in the delivery of energy substrates for mitochondrial metabolism by the intestinal epithelium.     

Obesity,Diabetes, and Gut Microbiota: The hygiene hypothesis expanded?

The connection between gut microbiota and energy homeostasis and inflammation and its role in the pathogenesis of obesity-related disorders are increasingly recognized. Animals models of obesity connect an altered microbiota composition to the development of obesity, insulin resistance, and diabetes in the host through several mechanisms: increased energy harvest from the diet, altered fatty acid metabolism and composition in adipose tissue and liver, modulation of gut peptide YY and glucagon-like peptide (GLP)-1 secretion, activation of the lipopolysaccharide toll-like receptor-4 axis, and modulation of intestinal barrier integrity by GLP-2. Instrumental for gut microbiota manipulation is the understanding of mechanisms regulating gut microbiota composition. Several factors shape the gut microflora during infancy: mode of delivery, type of infant feeding, hospitalization, and prematurity. Furthermore, the key importance of antibiotic use and dietary nutrient composition are increasingly recognized. The role of the Western diet in promoting an obesogenic gut microbiota is being confirmation in subjects. Following encouraging results in animals, several short-term randomized controlled trials showed the benefit of prebiotics and probiotics on insulin sensitivity, inflammatory markers, postprandial incretins, and glucose tolerance. Future research is needed to unravel the hormonal, immunomodulatory, and metabolic mechanisms underlying microbe-microbe and microbiota-host interactions and the specific genes that determine the health benefit derived from probiotics. While awaiting further randomized trials assessing long-term safety and benefits on clinical end points, a healthy lifestyle—including breast lactation, appropriate antibiotic use, and the avoidance of excessive dietary fat intake—may ensure a friendly gut microbiota and positively affect prevention and treatment of metabolic disorders.Along with the increasing worldwide incidence of obesity-associated disorders, research has recently unraveled important pathways reciprocally connecting metabolism with the immune system. The development of obesity is a complex process involving genetic susceptibility and environmental factors, which both remain only partially understood. In such instances, gut microbiota is being increasingly recognized as an important factor connecting genes, environment, and immune system. The human gut hosts an enormous number and variety of microorganisms, including at least 10¹⁴ bacteria belonging to ∼1,000 species (1). The genome size of this microbial organ, collectively named microbiome, exceeds the size of the human nuclear genome by two orders of magnitude and provides important biological and metabolic functions that cannot be performed by researchers. Genomic and environmental factors at the basis of mutual host-microbiota interactions have been intensely investigated with metagenomic and metabolomic approaches in the last 5 years. This article will discuss recent advances in understanding the role of gut microbiota in the pathogenesis of obesity, insulin resistance (IR), and diabetes and their potential therapeutic applications.     

Role of in vitamin D in irritable bowel syndrome

Irritable bowel syndrome (IBS) is a common chronic functional gastrointestinal disorder affecting 10%-22% of adults. Its development is closely related to the gut microbiota, and the inflammatory and immune responses triggered by the gut microbiota can lead to IBS. Vitamin D (VD) effectively treats IBS with fewer side effects by improving gut microbiota, immune regulation, and anti-inflammatory effects. In the future, it is necessary to carry out epidemiological studies on the relationship between VD and IBS, clinical studies on the efficacy of supplementing VD to improve IBS, and animal studies on the mechanism of VD improving IBS. Therefore, this paper discussed the relationship between VD and IBS.     

Update on gut microbiota in gastrointestinal diseases

The human gut is a complex microbial ecosystem comprising approximately 100 trillion microbes collectively known as the “gut microbiota”. At a rough estimate, the human gut microbiome contains almost 3.3 million genes, which are about 150 times more than the total human genes present in the human genome. The vast amount of genetic information produces various enzymes and physiologically active substances. Thus, the gut microbiota contributes to the maintenance of host health; however, when healthy microbial composition is perturbed, a condition termed “dysbiosis”, the altered gut microbiota can trigger the development of various gastrointestinal diseases. The gut microbiota has consequently become an extremely important research area in gastroenterology. It is also expected that the results of research into the gut microbiota will be applied to the prevention and treatment of human gastrointestinal diseases. A randomized controlled trial conducted by a Dutch research group in 2013 showed the positive effect of fecal microbiota transplantation (FMT) on recurrent Clostridioides difficile infection (CDI). These findings have led to the development of treatments targeting the gut microbiota, such as probiotics and FMT for inflammatory bowel diseases (IBD) and other diseases. This review focuses on the association of the gut microbiota with human gastrointestinal diseases, including CDI, IBD, and irritable bowel syndrome. We also summarize the therapeutic options for targeting the altered gut microbiota, such as probiotics and FMT.