肠道微生态改变与消化系统有关疾病的临床研究进展

正人体的肠道系统是一个较为复杂的微生物生态系统,内有大量的微生物群落,对于机体构建肠道黏膜屏障和维护肠道微生态平衡发挥重要作用。近几年来,随着社会经济发展和生活水平的提高,人们的生活习惯和饮食习惯也随之发生改变,消化系统疾病的发病率呈现出逐年上升的趋势。肠道微生态改变可直接影响消化系统物质代谢、消化、吸收等功能,微生物菌落改变可引发肠道炎性反应,对消化系统的免疫应答功能造成     

肠道微生态与炎症性肠病

炎症性肠病（IBD）是具有遗传易感性的个体对肠道微环境的改变发生持续的异常免疫反应,所导致的慢性炎症性疾病,肠道微生态的改变在IBD的发病中起到重要的作用,本文综述了肠道微生态的构成和作用、IBD患者微生态的改变以及与肠道微生态改变相关的治疗手段在IBD患者中的治疗前景。     

肠道微生态制剂的临床应用及进展

人体肠道是一个巨大的细菌库，在人体构成微生态平衡。若这种平衡破坏，出现菌群失调，将会引起许多相关疾病。微生态制剂是在微生态学理论的指导下，调节微生态失调，保持微生态平衡，提高宿主健康水平的生理性活菌制品(微生物)及其代谢产物以及促进这些生理菌群生长繁殖的物质制剂。目前广泛应用于临床，本文拟对肠道微生态制剂的临床应用和进展作一综述。     

肠道微生物在造血干细胞移植中的作用研究进展

移植物抗宿主病和感染是造血干细胞移植常见的并发症,是影响移植疗效及限制其广泛应用的主要原因。肠道微生物在维持肠道免疫平衡方面发挥重要作用,肠道微生物多样化水平与移植患者移植物抗宿主病、感染及患者预后密切相关,重塑肠道微生态能够改善移植物抗宿主病及感染情况。本文就肠道微生物在造血干细胞移植中的作用和机制,以及调节肠道微生态的策略等最新研究进展作一综述。     

功能性便秘患者肠道菌群分析及肠道菌群调节作用的研究进展

功能性便秘是一种常见的胃肠功能失调症。肠道菌群改变可能会导致便秘等肠道功能性疾病,而且肠道菌群的调节用于便秘等相关肠道功能性疾病的治疗疗效已得到确认。随着分子技术的发展,聚合酶链反应-变性梯度凝胶电泳(PCRDGGE)、实时荧光定量PCR(real-time quantitative PCR)、荧光原位杂交技术(FISH)、16S r RNA高通量焦磷酸测序等分子生物学技术逐步取代传统的细菌培养法,被广泛用于肠道菌群分析。不同研究得出的功能性便秘患者肠道菌群变化结果不尽一致,但大部分研究指出,功能性便秘患者肠道双歧杆菌下降以及肠道菌群物种丰富度降低。另一方面,肠道菌群的调节对功能性便秘的治疗疗效也不尽相同。益生菌(probiotics)、益生元(prebiotics)和合生元(synbiotics)等微生态制剂以及粪便菌群移植可用于肠道微生态调节。大多数研究指出,益生菌等可以明显改善患者的排便次数,减轻患者其他的相关症状。该文对功能性便秘患者肠道菌群的特征性改变以及微生态制剂对便秘的治疗疗效进行综述。     

肠道微生态对消化系统疾病的影响及其相关机制

肠道微生态(gut microbiome)系统是一个包含大量肠道微生物的复杂生态系统,也是人体微生态系统家族中最主要、最复杂的一员。肠道菌群对人体维生素合成、促进生长发育和物质代谢及免疫防御功能都有重要的作用。肠道菌群失调参与人体各系统多种疾病的发病过程,可引起多种全身性及消化系统疾病。肠道微生态在慢性肝病、炎症性肠病、功能性胃肠病、消化道肿瘤等疾病的发生发展中扮演了重要角色。     

肠道微生物群与代谢综合征相关骨关节炎关系研究进展

骨关节炎(osteoarthritis, OA)是一种多因素多病理改变的全关节疾病,在老年人群中患病率、致残率高,给社会造成巨大经济负担,但发病机制目前尚不明确。近些年有学者提出代谢综合征相关OA的概念,即某些OA的发生和进展与代谢异常紧密相关。肠道微生物群是一个复杂的生态系统,被认为与多种疾病相关。近些年有关肠道微生物群与代谢综合征相关OA关系的研究越来越多,但缺乏总结梳理。本文从肠道微生物群与代谢综合征相关OA的直接与间接关系,肠道微生物群影响代谢综合征相关OA发病的相关机制,以及改变肠道微生物群对代谢综合征相关OA的治疗作用与展望等方面进行综述,为防治代谢综合征相关OA提供理论依据。     

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。     

铁代谢与2型糖尿病相关性及胰高血糖素样肽-1调控作用的研究进展

铁代谢在多种代谢性疾病中发挥调控作用,过量铁积累会增加代谢性疾病尤其是2型糖尿病(T2DM)的发生风险。铁沉积、铁过载和铁死亡等病理过程可激活氧化应激、脂质过氧化、细胞自噬等,促进机体炎症反应级联放大和抗氧化能力降低,使胰岛β细胞功能逐渐衰退,从而促进T2DM的发生发展。胰高血糖素样肽-1(GLP-1)是由肠道L细胞分泌的一种生理性激素,GLP-1类似物或GLP-1受体激动剂可调节机体铁代谢过程,抑制铁沉积、铁过载和铁死亡相关炎症反应,促进胰岛β细胞增殖及分化,进而减轻胰岛素抵抗,抑制内皮细胞损伤,在T2DM及其并发症的防治中发挥重要作用。     

抗生素与肠道微生态的关系

肠道微生态由肠道正常菌群及其所生活的环境共同构成,肠道菌群承担着人体多种生理功能,包括免疫、代谢和内分泌功能等,被视为人体“器官”,在维持人体健康中起着至关重要的作用。抗生素常用于治疗各种感染性疾病,抗生素可消灭患者机体的大多数致病菌,但同时也严重破坏了肠道微生态平衡导致肠道菌群失调和各种急慢性疾病,抗生素对肠道微生物组成和结构的影响,取决于抗生素的种类、剂量和应用时间。本文综述了抗生素与肠道微生态的相互作用关系及其对健康和疾病的影响,以期为临床中使用抗生素的利弊权衡提供参考依据。     

肠道菌群与炎症性肠病

炎症性肠病(IBD)是发生于胃肠道的慢性复发性疾病,克罗恩病(CD)和溃疡性结肠炎(UC)为其两种主要表现形式,其致病因素及发病机制至今尚未完全阐明,但目前普遍认为IBD是由遗传因素、免疫功能紊乱、肠道屏障功能障碍和肠道菌群改变等多因素所致。随着16S rRNA基因检测技术的应用及肠道微生物宏基因组学计划的开展,人们对肠道微生物——"被遗忘的器官"有了更深刻的认识,其在IBD中的重要作用也逐渐被重视。研究认为IBD患者中宿主与肠道微生物之间精确的平衡关系被打破,从而触发了基因易感个体的免疫炎症反应。因此,调节肠道菌群紊乱,恢复宿主与肠道微生物之间的稳态成为治疗IBD的一个新方向。本文就IBD患者中存在的肠道菌群紊乱现象、其与IBD发病的关系以及微生态制剂在IBD治疗中的应用做一简要综述。     

Influence of gut microbiota on eye diseases: an overview

The microbiota is a dynamic ecosystem that plays a major role in the host health. Numerous studies have reported that alterations in the intestinal microbiota (dysbiosis) may contribute to the pathogenesis of various common diseases such as diabetes, neuropsychiatric diseases, and cancer. However, emerging findings also suggest the existence of a gut-eye axis, wherein gut dysbiosis may be a crucial factor influencing the onset and progression of multiple ocular diseases, including uveitis, dry eye, macular degeneration, and glaucoma. Currently, supplementation with pre- and probiotics appears is the most feasible and cost-effective approach to restore the gut microbiota to a eubiotic state and prevent eye pathologies. In this review, we discuss the current knowledge on how gut microbiota may be linked to the pathogenesis of common eye diseases, providing therapeutic perspectives for future translational investigations within this promising research field.     

Gut microbiota and its possible relationship with obesity

Obesity results from alterations in the body's regulation of energy intake, expenditure, and storage. Recent evidence, primarily from investigations in animal models, suggests that the gut microbiota affects nutrient acquisition and energy regulation. Its composition has also been shown to differ in lean vs obese animals and humans. In this article, we review the published evidence supporting the potential role of the gut microbiota in the development of obesity and explore the role that modifying the gut microbiota may play in its future treatment. Evidence suggests that the metabolic activities of the gut microbiota facilitate the extraction of calories from ingested dietary substances and help to store these calories in host adipose tissue for later use. Furthermore, the gut bacterial flora of obese mice and humans include fewer Bacteroidetes and correspondingly more Firmicutes than that of their lean counterparts, suggesting that differences in caloric extraction of ingested food substances may be due to the composition of the gut microbiota. Bacterial lipopolysaccharide derived from the intestinal microbiota may act as a triggering factor linking inflammation to high-fat diet-induced metabolic syndrome. Interactions among microorganisms in the gut appear to have an important role in host energy homeostasis, with hydrogen-oxidizing methanogens enhancing the metabolism of fermentative bacteria. Existing evidence warrants further investigation of the microbial ecology of the human gut and points to modification of the gut microbiota as one means to treat people who are over-weight or obese.     

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.     

Dietary polyphenols increase fecal mucin and immunoglobulin A and ameliorate the disturbance in gut microbiota caused by a high fat diet

The effects of dietary polyphenols on human health have mainly been discussed in the context of preventing degenerative diseases, particularly cardiovascular diseases and cancer. The antioxidant properties of polyphenols have been widely studied, but it has become clear that the mechanism of action of polyphenols extends beyond the modulation of oxidative stress, as they are poorly absorbed from the digestive tract. The purpose of this study was to clarify the effects of polyphenols on the colonic environment, intestinal barrier function, and gut microbiota. We demonstrated that dietary polyphenols derived from aronia, haskap, and bilberry, markedly elevated the amount of fecal mucin and immunoglobulin A (IgA) as an intestinal barrier function and ameliorated the disturbance in gut microbiota caused by a high fat diet in rats. These results suggest that dietary polyphenols play a significant role in the prevention of degenerative diseases through improvement of the colonic environment without any absorption from the digestive tract.     

Intestinal microecology-based treatment for inflammatory bowel disease: Progress and prospects

Inflammatory bowel disease (IBD) is a chronic, recurrent, and debilitating disorder, and includes Crohn’s disease and ulcerative colitis. The pathogenesis of IBD is closely associated with intestinal dysbiosis, but has not yet been fully clarified. Genetic and environmental factors can influence IBD patients’ gut microbiota and metabolism, disrupt intestinal barriers, and trigger abnormal immune responses. Studies have reported the alteration of gut microbiota and metabolites in IBD, providing the basis for potential therapeutic options. Intestinal microbiota-based treatments such as pre/probiotics, metabolite supplementation, and fecal microbiota transplantation have been extensively studied, but their clinical efficacy remains controversial. Repairing the intestinal barrier and promoting mucosal healing have also been proposed. We here review the current clinical trials on intestinal microecology and discuss the prospect of research and practice in this field.     

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。     

Gut microbiota correlates with energy gain from dietary fibre and appears to be associated with acute and chronic intestinal diseases

Improvements in high-throughput sequencing technologies have spurred a large number of studies aimed at obtaining a better understanding of the composition and the dynamics in gut microbiota and its associations with various human diseases, especially those in the intestinal tract. Here we briefly summarize results from three different such studies from our group, all of which used 454 based high-throughput 16S rRNA sequence analysis combined with other microbiota profiling methods to determine faecal microbiota composition. In the first study, a controlled feeding trial, we establish that energy gain from the consumption of up to 50 g/day of a resistant maltodextrin depends on the prevalent microbiota composition. Over time, resistant maltodextrin supplementation increased the proportion of total faecal bacteria as well as potentially beneficial bifidobacteria. Thus, energy gain from resistant maltodextrin in an individual appears to vary over time and depend on the adaptation of gut microbiota. We then illustrate the power of molecular tools for identifying (i) distortions in early microbiota development in pre-term infants and the presence of potentially novel pathogens contributing to necrotizing enterocolitis and (ii) a specific microbiota signature, based on discriminant analysis of the 16S rRNA sequences, that correlates with the prevalence of an early risk marker associated with colorectal carcinogenesis, intestinal adenoma, in elderly adults.