肠道菌群与非酒精性脂肪性肝病的关系

非酒精性脂肪性肝病(NAFLD)是一种常见的多因素参与的肝脏疾病,其发病率在全球逐渐上升。近年来发现肠道菌群参与了NAFLD的发生发展,从肠道菌群的影响因素、肠道菌群及其代谢产物在NAFLD发生发展中的作用等方面,综述了肠道菌群与NAFLD的关系,指出针对肠道菌群及其代谢产物的干预策略可能是预防和治疗NAFLD的新靶点。     

肠道菌群及其代谢产物在非酒精性脂肪性肝病发生发展及治疗中的作用

非酒精性脂肪性肝病(NAFLD)是全世界最为常见的慢性肝病。肝脏与肠道之间有着紧密的结构及功能关系即“肠-肝轴”,其中肠道菌群可通过菌群易位、内源性乙醇的产生、胆汁酸和胆碱代谢的调节异常、内毒素血症等参与NAFLD的发生、发展。本文主要关注肠道菌群及代谢产物在NAFLD发生、发展及治疗中的作用进展。     

肠道微生态失衡与非酒精性脂肪性肝病的关系

肠道微生态系统由定植于肠道的固有菌群、肠上皮细胞、肠黏膜免疫系统组成。非酒精性脂肪性肝病(NAFLD)是一种与胰岛素抵抗和遗传易感性相关的代谢应激性肝损伤。近年来关于肠道微生态与NAFLD发病机制关系的研究越来越多。肠道微生态失衡导致的肠道菌群过度生长、肠黏膜通透性增加、肠源性内毒素血症、炎症因子产生等在NAFLD的发生发展过程中扮演着重要的角色。深入研究肠道微生态失衡与NAFLD的关系将有助于为NAFLD的治疗及预防提供新方向。     

基于肠道菌群的非酒精性脂肪性肝病防治新策略

非酒精性脂肪性肝病(NAFLD)的发生率不断上升,目前仍缺乏有效治疗方法。有研究表明肠道菌群变化在NAFLD发展过程中扮演着重要的角色,因此可通过调节肠道菌群达到治疗目的。该文总结近年来动物和临床研究结果,从机制上阐述肠道菌群与NAFLD的关系,同时综述通过调节与肠道菌群有关的短链脂肪酸及胆汁酸代谢来治疗NAFLD的研究新进展。     

肠道菌群失调——非酒精性脂肪肝病治疗新靶点

非酒精性脂肪肝病(non-alcoholic fatty liver disease,NAFLD)是一种除饮酒以及其他肝损害因素外所致的以肝实质细胞脂肪变性及贮积为特征的临床病理综合征.近年来,随着人们生活方式的改变,NAFLD已成为全球公共健康问题,其发生率与肥胖、2型糖尿病等代谢综合征相关.越来越多文献表明肠道菌群与NAFLD的发生发展关系密切:(1)肠道菌群失调可促进宿主吸收更多的能量;(2)肠道菌群失调可诱导机体脂质代谢紊乱,肝细胞脂质蓄积;(3)肠道菌群失调可增加肠黏膜通透性、促发炎症.因此,本文就肠道菌群与NAFLD关系进行整理,为寻找治疗NAFLD的药物提供新靶点进行简要综述.     

非酒精性脂肪性肝病与肠道菌群的关系

非酒精性脂肪性肝病(non-alcoholic fatty liver disease,NAFLD)是一种多病因导致的临床病理综合征,已成为最常见的慢性肝病之一,目前NAFLD完整的生理机制尚不完全清楚,近年来提出肠道菌群通过调控能量代谢、增加内源性乙醇、调节胆汁酸及胆碱代谢,破坏免疫平衡引发机体低度炎症等途径促进NAFLD的发生、发展,本文就肠道菌群与NAFLD的相关机制做一概述。     

肠道菌群及其代谢物与非酒精性脂肪性肝病

总结相关的实验研究发现,人体肠道菌群是非酒精性脂肪性肝病(NAFLD)发生发展的关键因素,除了人体肠道菌群组成的变化外,肠道菌群的代谢物也成为调节NAFLD病理过程的关键因素;有研究发现,肠道菌群的代谢物如短链脂肪酸、胆汁酸、三甲胺和乙醇等通过肠-肝轴途径影响肝脏代谢功能,从而导致疾病发生。现从NAFLD患者肠道菌群和代谢物的变化及发病机制,总结并探讨通过调节肠道菌群及其代谢物来治疗NAFLD,期望这些治疗策略会成为未来优化治疗NAFLD等代谢性肝病的有效方法。     

肠道微生态变化与非酒精性脂肪性肝病研究进展

由定植于肠道的大量固有菌群、肠道上皮细胞及肠道局部粘膜免疫系统组成了肠道微生态系统。"肝-肠轴"概念的提出为从肠道微生态角度寻找非酒精性脂肪性肝病(NAFLD)的诊疗措施提供了依据。肠道微生态失衡所致的肠道菌群过度生长、肠黏膜通透性改变、免疫功能紊乱、肠源性内毒素血症、效应细胞激活及炎症因子生成等在NAFLD发生发展中发挥了不容忽视的作用。深入研究肠道菌群与NAFLD之间的关系将为NAFLD的预防和治疗提供新靶点。     

肠道菌群代谢产物与非酒精性脂肪性肝病关系的研究进展

非酒精性脂肪性肝病(NAFLD)是一种常见的慢性肝脏疾病,其发病率呈逐年上升趋势。NAFLD的发病机制尚未完全阐明,目前研究显示肠道菌群分泌的代谢产物在NAFLD的发生发展过程中起着重要作用,包括调节能量平衡,作为信号分子参与信号转导,直接作用于肝脏细胞等。该文对近年来肠道菌群代谢产物(如短链脂肪酸、氧化三甲胺、胆汁酸及内生性乙醇等)与NAFLD关系的相关研究作一综述,并探讨基于肠道菌群代谢产物的NAFLD防治策略。     

饮食对非酒精性脂肪性肝病患者肠道菌群的影响

非酒精性脂肪性肝病(NAFLD)是常见的慢性肝病,肠道菌群通过"肠肝轴"与肝脏相互作用,其与NAFLD的发生和发展密切相关。近年来越来越多的研究揭示了饮食因素在肠道微生态改变和NAFLD发病中的作用。该文综述了膳食胆碱、脂肪、果糖、膳食纤维和蛋白质等饮食因素对肠道菌群的影响及其与NAFLD的关系,以期为进一步探讨饮食干预防治NAFLD提供依据。     

Gut microbiota and non-alcoholic fatty liver disease

BACKGROUND: Non-alcoholic fatty liver disease(NAFLD) is a common disorder with poorly understood pathogenesis. Beyond environmental and genetic factors,cumulative data support the causative role of gut microbiota in disease development and progression.DATA SOURCE: We performed a Pub Med literature search with the following key words: "non-alcoholic fatty liver disease","non-alcoholic steatohepatitis","fatty liver","gut microbiota" and "microbiome",to review the data implicating gut microbiota in NAFLD development and progression.RESULTS: Recent metagenomic studies revealed differences in the phylum and genus levels between patients with fatty liver and healthy controls. While bacteroidetes and firmicutes remain the dominant phyla among NAFLD patients,their proportional abundance and genera detection vary among different studies. New techniques indicate a correlation between the methanogenic archaeon(methanobrevibacter smithii) and obesity,while the bacterium akkermanshia municiphila protects against metabolic syndrome. Among NAFLD patients,small intestinal bacterial overgrowth detected by breath tests might induce gut microbiota and host interactions,facilitating disease development.CONCLUSIONS: There is evidence that gut microbiota participates in NAFLD development through,among others,obesity induction,endogenous ethanol production,inflammatory response triggering and alterations in choline metabolism. Further studies with emerging techniques are needed to further elucidate the microbiome and host crosstalk in NAFLD pathogenesis.     

Role of gut microbial metabolites in nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is a common, multifactorial liver disease that has emerged as a global challenge due to its increasing prevalence and lack of sustainable treatment options. Gut microbiota possess vital functions in fermenting dietary nutrients and synthesizing bioactive molecules. This function is of great importance in maintaining health because these microbial metabolites are essential in regulating energy metabolism, immune response, and other vital physiological processes. Altered gut flora can result in a change in gut microbial metabolites, affecting the onset and progression of multiple diseases. In this review we summarize the metabolites that may have beneficial or harmful effects on the development and progression of NAFLD. This will help us better understand the possible mechanisms underlying the pathogenesis of NAFLD and facilitate the identification of potential therapeutic approaches for NAFLD.     

肠道微生物在非酒精性脂肪肝发生发展中的作用机制

非酒精性脂肪肝是代谢综合征的肝脏表现,可发展为肝硬化和肝癌。非酒精性脂肪肝的病因尚未明确,近年来宿主肠道微生物在非酒精性脂肪肝的发生、发展及治疗中的作用越来越受到重视。目前认为人类肠道是一个内在重要的代谢及免疫器官,肠道微生物的组成可影响宿主代谢,改变肠道通透性,引起炎症及一系列免疫反应。本文就肠道微生物在非酒精性脂肪肝的病理生理过程中的作用机制进行综述。     

粪菌移植治疗非酒精性脂肪性肝病研究进展

非酒精性脂肪肝病（non-alcoholic fatty liver disease, NAFLD）的发病率在世界范围内呈明显上升趋势,由于目前尚无确切的特效治疗方式,严重影响人类健康。近年来,越来越多的研究表明肠道菌群通过肝-肠轴影响肝功能,肠道菌群失调是NAFLD发病的重要原因。因此,纠正肠道菌群失调,可以预防和减轻NAFLD的发生、发展。粪菌移植（fecal microbiota transplantation, FMT）被认为是纠正肠道菌群失调最有效的方法,但其在NAFLD中的治疗作用还未明确。此外,FMT治疗NAFLD的潜在分子机制也尚未阐明。本文就FMT治疗NAFLD的研究现状进行总结,并发掘其潜在的分子机制,为FMT作为治疗NAFLD的有效手段提供理论支持。     

Microbiota and nonalcoholic fatty liver disease/nonalcoholic steatohepatitis (NAFLD/NASH)

Genetic predisposition, the intestinal microbiota (IM) and environmental factors, such as sedentary lifestyle and inadequate diet, should be considered as critical factors for the development of nonalcoholic fatty liver disease (NAFLD). Recently, some studies have demonstrated an association between dysbiosis and NAFLD; however, the exact mechanisms that lead to intestinal membrane damage, bacterial translocation and inflammation are not well elucidated. Due to the relevance of this theme, the IM and its metabolites have received special attention in recent years in an attempt to better understand the mechanisms related to the prevention, physiopathology, and treatment of NAFLD. In this paper, we provide a review of the human IM and its role in diet, obesity, and the development/progression of NAFLD/NASH, as well as the use of prebiotics and probiotics in the modulation of IM.     

Role of gut microbiota and Toll-like receptors in nonalcoholic fatty liver disease

Emerging data have shown a close association between compositional changes in gut microbiota and the development of nonalcoholic fatty liver disease (NAFLD). The change in gut microbiota may alter nutritional absorption and storage. In addition, gut microbiota are a source of Toll-like receptor (TLR) ligands, and their compositional change can also increase the amount of TLR ligands delivered to the liver. TLR ligands can stimulate liver cells to produce proinflammatory cytokines. Therefore, the gut-liver axis has attracted much interest, particularly regarding the pathogenesis of NAFLD. The abundance of the major gut microbiota, including Firmicutes and Bacteroidetes, has been considered a potential underlying mechanism of obesity and NAFLD, but the role of these microbiota in NAFLD remains unknown. Several reports have demonstrated that certain gut microbiota are associated with the development of obesity and NAFLD. For instance, a decrease in Akkermansia muciniphila causes a thinner intestinal mucus layer and promotes gut permeability, which allows the leakage of bacterial components. Interventions to increase Akkermansia muciniphila improve the metabolic parameters in obesity and NAFLD. In children, the levels of Escherichia were significantly increased in nonalcoholic steatohepatitis (NASH) compared with those in obese control. Escherichia can produce ethanol, which promotes gut permeability. Thus, normalization of gut microbiota using probiotics or prebiotics is a promising treatment option for NAFLD. In addition, TLR signaling in the liver is activated, and its downstream molecules, such as proinflammatory cytokines, are increased in NAFLD. To data, TLR2, TLR4, TLR5, and TLR9 have been shown to be associated with the pathogenesis of NAFLD. Therefore, gut microbiota and TLRs are targets for NAFLD treatment.     

Intestinal microbiome and NAFLD: molecular insights and therapeutic perspectives

Non-alcoholic fatty liver disease (NAFLD) is the hepatic manifestation of dysregulated lipid and glucose metabolism, which is often associated with obesity, dyslipidemia and insulin resistance. In view of the high morbidity and health risks of NAFLD, the lack of effective cure has drawn great attention. In recent years, a line of evidence has suggested a close linkage between the intestine and liver diseases such as NAFLD. We summarized the composition and characteristics of intestinal microbes and reviewed molecular insights into the intestinal microbiome in development and progression of NAFLD. Intestinal microbes mainly include bacteria, archaea, viruses and fungi, and the crosstalk between non-bacterial intestinal microbes and human liver diseases should be paid more attention. Intestinal microbiota imbalance may not only increase the intestinal permeability to gut microbes but also lead to liver exposure to harmful substances that promote hepatic lipogenesis and fibrosis. Furthermore, we focused on reviewing the latest “gut–liver axis”-targeting treatment, including the application of antibiotics, probiotics, prebiotics, synbiotics, farnesoid X receptor agonists, bile acid sequestrants, gut-derived hormones, adsorbents and fecal microbiota transplantation for NAFLD. In this review, we also discussed the potential mechanisms of “gut–liver axis” manipulation and efficacy of these therapeutic strategies for NAFLD treatment.

     

Apoptosis and non-alcoholic fatty liver diseases

The number of patients with nonalcoholic fatty liver diseases(NAFLD) including nonalcoholic steatohepatitis(NASH), has been increasing. NASH causes cirrhosis and hepatocellular carcinoma(HCC) and is one of the most serious health problems in the world. The mechanism through which NASH progresses is still largely unknown. Activation of caspases, Bcl-2 family proteins, and c-Jun N-terminal kinase-induced hepatocyte apoptosis plays a role in the activation of NAFLD/NASH. Apoptotic hepatocytes stimulate immune cells and hepatic stellate cells toward the progression of fibrosis in the liver through the production of inflammasomes and cytokines. Abnormalities in glucose and lipid metabolism as well as microbiota accelerate these processes. The production of reactive oxygen species, oxidative stress, and endoplasmic reticulum stress is also involved. Cell death, including apoptosis, seems very important in the progression of NAFLD and NASH. Recently, inhibitors of apoptosis have been developed as drugs for the treatment of NASH and may prevent cirrhosis and HCC. Increased hepatocyte apoptosis may distinguish NASH from NAFLD, and the improvement of apoptosis could play a role in controlling the development of NASH. In this review, the association between apoptosis and NAFLD/NASH are discussed. This review could provide their knowledge, which plays a role in seeing the patients with NAFLD/NASH in daily clinical practice.     

The role of the gut microbiota in nonalcoholic fatty liver disease

Important metabolic functions have been identified for the gut microbiota in health and disease. Several lines of evidence suggest a role for the gut microbiota in both the etiology of nonalcoholic fatty liver disease (NAFLD) and progression to its more advanced state, nonalcoholic steatohepatitis (NASH). Both NAFLD and NASH are strongly linked to obesity, type 2 diabetes mellitus and the metabolic syndrome and, accordingly, have become common worldwide problems. Small intestinal bacterial overgrowth of Gram-negative organisms could promote insulin resistance, increase endogenous ethanol production and induce choline deficiency, all factors implicated in NAFLD. Among the potential mediators of this association, lipopolysaccharide (a component of Gram-negative bacterial cell walls) exerts relevant metabolic and proinflammatory effects. Although the best evidence to support a role for the gut microbiota in NAFLD and NASH comes largely from animal models, data from studies in humans (albeit at times contradictory) is accumulating and could lead to new therapeutic avenues for these highly prevalent conditions.     

Periodontal treatment and microbiome-targeted therapy in management of periodontitis-related nonalcoholic fatty liver disease with oral and gut dysbiosis

A growing body of evidence from multiple areas proposes that periodontal disease, accompanied by oral inflammation and pathological changes in the microbiome, induces gut dysbiosis and is involved in the pathogenesis of nonalcoholic fatty liver disease (NAFLD). A subgroup of NAFLD patients have a severely progressive form, namely nonalcoholic steatohepatitis (NASH), which is characterized by histological findings that include inflammatory cell infiltration and fibrosis. NASH has a high risk of further progression to cirrhosis and hepatocellular carcinoma. The oral microbiota may serve as an endogenous reservoir for gut microbiota, and transport of oral bacteria through the gastro-intestinal tract can set up a gut microbiome dysbiosis. Gut dysbiosis increases the production of potential hepatotoxins, including lipopolysaccharide, ethanol, and other volatile organic compounds such as acetone, phenol and cyclopentane. Moreover, gut dysbiosis increases intestinal permeability by disrupting tight junctions in the intestinal wall, leading to enhanced translocation of these hepatotoxins and enteric bacteria into the liver through the portal circulation. In particular, many animal studies support that oral administration of Porphyromonas gingivalis, a typical periodontopathic bacterium, induces disturbances in glycolipid metabolism and inflammation in the liver with gut dysbiosis. NAFLD, also known as the hepatic phenotype of metabolic syndrome, is strongly associated with metabolic complications, such as obesity and diabetes. Periodontal disease also has a bidirectional relationship with metabolic syndrome, and both diseases may induce oral and gut microbiome dysbiosis with insulin resistance and systemic chronic inflammation cooperatively. In this review, we will describe the link between periodontal disease and NAFLD with a focus on basic, epidemiological, and clinical studies, and discuss potential mechanisms linking the two diseases and possible therapeutic approaches focused on the microbiome. In conclusion, it is presumed that the pathogenesis of NAFLD involves a complex crosstalk between periodontal disease, gut microbiota, and metabolic syndrome. Thus, the conventional periodontal treatment and novel microbiome-targeted therapies that include probiotics, prebiotics and bacteriocins would hold great promise for preventing the onset and progression of NAFLD and subsequent complications in patients with periodontal disease.