非酒精性脂肪性肝炎患者肝组织NF-кβ的表达及其意义

目的探讨核因子κβ（NF-κβ）在非酒精性脂肪性肝炎（NASH）患者肝组织中的表达状况及在发病机制中的意义。方法应用免疫组化方法检测41例不同病变程度NASH患者肝组织NF-κβ表达，分析其与NASH患者肝组织病理改变以及血清TNF-α、胰岛素抵抗（IR）之间的关系，并与39例酒精性脂肪肝、50例NASH合并慢性乙型肝炎（CHB）患者进行比较。结果与正常人肝组织中NF-κβ（1．13±0．05）表达比较，NASH（5．09±1．30）、酒精性脂肪肝（4．07±1．54）和NASH合并CHB（6．40±1．41）患者表达均明显增强（P〈0．05）；在NASH肝组织中，NF-κβ表达于肝脂肪变区及炎症活动区的肝窦壁细胞及炎细胞中，其阳性表达随肝脏炎症损伤程度和纤维化程度的加重而增加（P〈0．05），与血清TNF-α水平和IR成正相关（P〈0．05），而与脂肪变程度无明显相关性（P〉0．05）。结论不同类型的脂肪性肝病均存在胰岛素抵抗和肝组织NF-κβ的活化，NF-κβ的活化是非酒精性脂肪肝胰岛素抵抗持续进展的一个重要机制。     

细胞因子在非酒精性脂肪性肝炎发病机制中的作用

随着非酒精性脂肪性肝病发病率的逐年上升及其对健康的危害,包括3种类型:单纯性脂肪肝、脂肪性肝炎和脂肪性肝硬化已受到越来越多的重视,而非酒精性脂肪性肝炎是由单纯性脂肪肝发展为脂肪性肝硬化的必经阶段,了解其发病机制,探讨具有多种生物学效应的细胞因子在非酒精性脂肪性肝炎中的作用,对于弄清其发病机制的多样性有着深刻的意义。     

吡格列酮对大鼠非酒精性脂肪性肝炎干预的实验研究

目的　用吡格列酮对试验动物进行干预 ,探讨胰岛素抵抗与非酒精性脂肪性肝炎的关系。方法　雄性SD大鼠 5 0只随机分组。正常对照组喂饲普通饮食 ,高脂模型组喂饲高脂饮食 ,给药组分别在喂饲高脂饮食 4周后、9周后分别给予吡格列酮灌胃 ,并分别在 9周末及 14周末处死各组大鼠 ,测定血清转氨酶、血糖、血脂、胰岛素及FFA水平 ,观察肝组织学改变。结果　 9周后模型组大鼠呈现明显腹型肥胖 ,产生脂质代谢紊乱及胰岛素抵抗 ,肝脏出现肝细胞脂肪变性 ,给药组各项指标均有明显改善 ;14周后模型组大鼠血清转氨酶水平升高 ,肝脏出现炎细胞浸润 ,除肝组织炎症外 ,给药组其他指标均有不同程度的改善。结论　胰岛素抵抗在大鼠肝脏脂肪变的发生中起到关键作用 ,与脂肪肝发生炎症坏死关系甚密切 :吡格列酮可明显改善高脂饮食诱发大鼠肝脏的脂肪变性 ,对炎症变化作用不明显     

Current pharmacological therapies for nonalcoholic fatty liver disease/nonalcoholic steatohepatitis

Nonalcoholic fatty liver disease(NAFLD)/nonalcoholic steatohepatitis(NASH) is considered to be a hepatic manifestation of metabolic syndrome, and its incidence is rapidly increasing worldwide. It is currently the most common chronic liver disease. NASH can progress to liver cirrhosis and hepatocellular carcinoma, and may result in liver-related death. Currently, the principal treatment for NAFLD/NASH is lifestyle modification by diet and exercise. However, pharmacological therapy is indispensable because obese patients with NAFLD often have difficulty maintaining improved lifestyles. The pathogenesis of NAFLD/NASH has not been completely elucidated. However, insulin resistance, inflammatory cytokines, and oxidative stress are thought to be important in the development and/or progression of the disease. Currently, insulin sensitizers(thiazolidinediones) and antioxidants(vitamin E) seem to be the most promising therapeutic agents for NAFLD/NASH, and lipid-lowering drugs, pentoxifylline, angiotensin receptor blockers, and n-3 polyunsaturated fatty acids also have promise. However, there is a lack of consensus regarding the most effective and appropriate pharmacotherapy for NAFLD/NASH. Animal experiments suggest that herbal medicines and natural products may be promising therapeutic agents for NAFLD/NASH, but their efficacy and safety are yet to be investigated in human studies. In this paper, we review the existing and potential pharmacological therapies for NAFLD/NASH.     

脂联素在非酒精性脂肪肝中的作用及机制

脂联素是由脂肪细胞分泌的胰岛素敏感性脂肪因子,其对非酒精性脂肪肝病(NAFLD)有多种有益作用.在循环中脂联素有3种低聚亚型,包括三聚体、六聚体及高分子量低聚复合物.脂联素通过与靶器官上脂联素受体结合来发挥效应,其保肝作用已经在临床和实验室研究中证明.脂联素的下降是NAFLD及肝脏功能损害的独立危险因素.在动物实验中,通过药物或基因疗法使循环中的脂联素增高可导致肝肿大、脂肪变、坏死炎症及其相关肝脏疾病.脂联素敲除的小鼠,会发生肝脂肪变和线粒体功能损害,这致使小鼠易于遭受脂肪肝病的二次打击.本文旨在综述近年来对于脂联素在NAFLD中的保肝作用及机制的研究成果.     

内毒素在非酒精性脂肪性肝炎发病机制中的作用

内毒素是导致肝损伤的一个重要因素,近年来研究证实,内毒素除直接诱导肝细胞凋亡、坏死外,还可活化多种肝脏间质细胞,产生、释放大量炎症介质和细胞因子,造成肝脏严重的炎症反应,从而在非酒精性脂肪性肝炎发病机制中发挥重要作用.     

抵抗素mRNA在非酒精性脂肪性肝炎大鼠肝组织中的表达与定位

目的观察高脂饮食诱导的非酒精性脂肪性肝炎（NASH）大鼠肝组织抵抗素mRNA的表达与定位，探讨其在NASH发病中的作用。方法16只雄性Wistar大鼠被随机分为普通饲料和高脂饲料喂养组，连续18周后处死各组大鼠，测定血清甘油三酯（TG）、总胆固醇（TC）、高密度脂蛋白胆固醇（HDL-C）、低密度脂蛋白胆固醇（LDL-C）、游离脂肪酸（FFA）、肿瘤坏死因子（TNF-α）、空腹血糖（FBS）和空腹胰岛素（FINS），并计算胰岛素敏感指数（ISI），观察肝脏组织病理变化和炎症活动度计分；应用原位杂交和半定量RT—PCR技术检测各组大鼠肝脏组织抵抗素mRNA的表达及定位。结果模型组肝组织抵抗素mRNA表达较正常组显著性升高，其阳性颗粒主要分布于小叶内及汇管区炎细胞浸润区的巨噬细胞胞浆中。模型组肝组织抵抗素和血清TNF-α水平、肝脏炎症活动度计分成显著性正相关（r=0．873，0．892，P〈0．01），但与ISI无相关。结论NASH模型大鼠肝脏抵抗素定位于小叶内及汇管区炎细胞浸润区的巨噬细胞胞浆中，参与NASH的炎症发病机制。     

Hypolactasia is associated with insulin resistance in nonalcoholic steatohepatitis

AIM To assess lactase gene(LCT)-13910CT polymorphisms in Brazilian non-alcoholic fatty liver disease(NAFLD) and nonalcoholic steatohepatitis(NASH) patients in comparison with healthy controls.METHODS This was a transverse observational clinical study with NAFLD patients who were followed at the Hepatology Outpatient Unit of the Hospital das Clínicas, S?o Paulo, Brazil. The polymorphism of lactase non-persistence/lactase persistence(LCT-13910CT) was examined by PCR-restriction fragment length polymorphism technique in 102 liver biopsy-proven NAFLD patients(steatosis in 9 and NASH in 93) and compared to those of 501 unrelated healthy volunteers. Anthropometric, clinical, biochemical and liver histology data were analyzed. Continuous variables were compared using the t or Mann-Whitney tests, and categorical data were compared with the Fisher's exact test. Univariate logistic regression and multivariate logistic regression adjusted for gender and age were performed.RESULTS No differences in the LCT-13910 genotype frequencies were noted between the NAFLD patients(66.67% of the patients with steatosis were CC, 33.33% were CT, and none were TT; 55.91% of the patients with NASH were CC, 39.78% were CT, and 4.3% were TT; P = 0.941) and the healthy controls(59.12% were CC, 35.67% were CT, and 5.21% were TT) or between the steatosis and NASH patients. That is, the distribution of the lactase non-persistence/lactase persistence polymorphism(LCT-13910CT) in the patients with NAFLD was equal to that in the general population. In the NASH patients, the univariate analysis revealed that the lactase nonpersistence(low lactase activity or hypolactasia) phenotype was associated with higher insulin levels(23.47 ± 15.94 μU/m L vs 15.8 ± 8.33 μU/m L, P = 0.027) and a higher frequency of insulin resistance(91.84% vs 72.22%, P = 0.02) compared with the lactase persistence phenotype. There were no associations between the LCT genotypes and diabetes(P = 0.651), dyslipidaemia(P = 0.328), hypertension(P = 0.507) or liver histology in these patients. Moreover, in the NASH patients, hypolactasia was an independent risk factor for insulin resistance even after adjusting for gender and age [OR = 5.0(95%CI: 1.35-20; P = 0.017)].CONCLUSION The LCT-13910 genotype distribution in Brazilian NAFLD patients was the same as that of the general population, but hypolactasia increased the risk of insulin resistance in the NASH patients.     

Limitations of liver biopsy and non-invasive diagnostic tests for the diagnosis of nonalcoholic fatty liver disease/nonalcoholic steatohepatitis

It is estimated that 30%of the adult population in Japan is affected by nonalcoholic fatty liver disease(NAFLD).Fatty changes of the liver are generally diagnosed using imaging methods such as abdominal ultrasonography(US)and computed tomography(CT),but the sensitivity of these imaging techniques is low in cases of mild steatosis.Alanine aminotransferase levels may be normal in some of these patients,warranting the necessity to establish a set of parameters useful for detecting NAFLD,and the more severe form of the disease,nonalcoholic steatohepatitis(NASH).Although liver biopsy is currently the gold standard for diagnosing progressive NASH,it has many drawbacks,such as sampling error,cost,and risk of complications.Furthermore,it is not realistic to perform liver biopsies on all NAFLD patients.Diagnosis of NASH using various biomarkers,scoring systems and imaging methods,such as elastography,has recently been attempted.The NAFIC score,calculated from the levels of ferritin,fasting insulin,and typeⅣcollagen 7S,is useful for the diagnosis of NASH,while the NAFLD fibrosis score and the FIB-4 index are useful for excluding NASH in cases of advanced fibrosis.This article reviews the limitations and merits of liver biopsy and noninvasive diagnostic tests in the diagnosis of NAFLD/NASH.     

黄连素灌胃对非酒精性脂肪性肝炎小鼠肠道菌群的影响

目的了解黄连素调节肠道菌群对非酒精性脂肪性肝炎的影响。方法将Babl/c小鼠随机分为对照组(n=10)、模型组(n=10)和干预组(n=15)。采用高脂饮食法制备脂肪肝模型,自第5周起,给予干预组小鼠黄连素(200mg·kg-1)灌胃至第13周结束。采用荧光定量PCR法相对定量检测CD14、IL-6、IL-1、TNF-α及进行盲肠内容物中双歧杆菌和乳酸菌计数。结果在13周末,模型组小鼠肝组织病理学检查显示明显的脂肪变和炎症改变,NAFLD活动度计分(NAS)为4.60±1.07,明显高于对照组(0.44±0.53,P<0.01);模型组血清ALT为346.00±142.01U/L,显著高于对照组(120.00±10.22U/L,P<0.01);肝组织IL-1mRNA为1.539±0.437、IL-6为0.580±0.083和TNF-α为4.482±0.820,显著高于对照组(分别为0.421±0.083、0.258±0.084和1.336±0.156,P均<0.01);模型组盲肠内容物中双歧杆菌数量为0.495±0.082,乳酸菌数量为0.010±0.006,显著低于对照组(分别为1.334±0.709和94.682±64.089,P均<0.05);与模型组比,干预组肝组织小叶内炎症明显减轻,NAS为2.73±0.90,显著低于模型组(4.60±1.07,P<0.01),生化指标较模型组改善,其中ALT为175.00±20.14U/L,显著低于模型组(346.00±142.01U/L,P<0.01),肝组织CD14为0.045±0.006、IL-1为0.243±0.067、IL-6为0.249±0.046和TNF-α为0.553±0.553,显著低于模型组(分别为0.321±0.106、1.539±0.437、0.580±0.083和4.482±0.820,P均<0.01),盲肠内容物中乳酸菌和双歧杆菌数量均较模型组增多,其中双歧杆菌(2.160±0.629)显著高于模型组(0.495±0.082,P<0.01)。结论高脂饮食喂养的Babl/c小鼠灌胃黄连素后,可能因为调整了肠道菌群,使肝内脂肪性炎症明显减轻。     

Promising diagnostic biomarkers of nonalcoholic fatty liver disease and nonalcoholic steatohepatitis: From clinical proteomics to microbiome

Fatty liver has been present in the lives of patients and physicians for almost two centuries. Vast knowledge has been generated regarding its etiology and consequences, although a long path seeking novel and innovative diagnostic biomarkers for nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) is still envisioned. On the one hand, proteomics and lipidomics have emerged as potential noninvasive resources for NAFLD diagnosis. In contrast, metabolomics has been able to distinguish between NAFLD and NASH, even detecting degrees of fibrosis. On the other hand, genetic and epigenetic markers have been useful in monitoring disease progression, eventually functioning as target therapies. Other markers involved in immune dysregulation, oxidative stress, and inflammation are involved in the instauration and evolution of the disease. Finally, the fascinating gut microbiome is significantly involved in NAFLD and NASH. This review presents state-of-the-art biomarkers related to NAFLD and NASH and new promises that could eventually be positioned as diagnostic resources for this disease. As is evident, despite great advances in studying these biomarkers, there is still a long path before they translate into clinical benefits.     

Insulin resistance in development and progression of nonalcoholic fatty liver disease

Although insulin resistance(IR)is strongly associated with nonalcoholic fatty liver disease(NAFLD),the association of IR and NAFLD is not universal and correlation between IR and severity of NAFLD is still controversial.In this review,we summarize recent evidence that partially dissociates insulin resistance from NAFLD.It has also been reported that single-nucleotide polymorphisms in the diacylglycerol acyltransferase gene,rather than IR,account for the variability in liver fat content.Polymorphisms of the patatin-like phospholipase 3 gene have also been reported to be associated with NAFLD without metabolic syndrome,which suggests that genetic conditions that promote the development of fatty changes in the liver may occur independently of IR.Moreover,environmental factors such as nutrition and physical activity as well as small intestinal bacterial overgrowth have been linked to the pathogenesis of NAFLD,although some of the data are conflicting.Therefore,findings from both genetically engineered animal models and humans with genetic conditions,as well as recent studies that have explored the role of environmental factors,have confirmed the view that NAFLD is a polygenic disease process caused by both genetic and environmental factors.Therefore,IR is not the sole predictor of the pathogenesis of NAFLD.     

Dynamic alterations in the gut microbiota and metabolomeduring the development of methionine-choline-deficient diet-induced nonalcoholic steatohepatitis

AIM To investigate changes in gut microbiota and metabolism during nonalcoholic steatohepatitis(NASH) development in mice fed a methionine-choline-deficient(MCD) diet. METHODS Twenty-four male C57 BL/6 J mice were equally divided into four groups and fed a methionine-choline-sufficient diet for 2 wk(Control 2 w group,n = 6) or 4 wk(Control 4 w group,n = 6) or the MCD diet for 2 wk(MCD 2 w group,n = 6) or 4 wk(MCD 4 w group,n = 6). Liver injury,fibrosis,and intestinal barrier function were evaluated after 2 and 4 wk of feeding. The fecal microbiome and metabolome were studied using 16 s r RNA deep sequencing and gas chromatography-mass spectrometry. RESULTS The mice fed the MCD diet presented with simple hepatic steatosis and slight intestinal barrier deterioration after 2 wk. After 4 wk of feeding with the MCD diet,however,the mice developed prominent NASH with liver fibrosis,and the intestinal barrier was more impaired. Compared with the control diet,the MCD diet induced gradual gut microbiota dysbiosis,as evidenced by a marked decrease in the abundance of Alistipes and the(Eubacterium) coprostanoligenes group(P 0.001 and P 0.05,respectively) and a significant increase in Ruminococcaceae UCG 014 abundance(P 0.05) after 2 wk. At 4 wk,the MCD diet significantly reduced the promising probiotic Bifidobacterium levels and markedly promoted Bacteroides abundance(P 0.05,and P 0.01,respectively). The fecal metabolomic profile was also substantially altered by the MCD diet: At 2 wk,arachidic acid,hexadecane,palmitic acid,and tetracosane were selected as potential biomarkers that were significantly different in the corresponding control group,and at 4 wk,cholic acid,cholesterol,arachidic acid,tetracosane,and stearic acid were selected. CONCLUSION The MCD diet induced persistent alterations in the gut microbiota and metabolome.     

非酒精性脂肪性肝炎诊断的研究进展

疾病的诊断均从问病史开始,体检、生物化学指标的检测、影像诊断、组织学检查等.体重指数和腰臀比例可作为NAFLD发生的有效预测指标,血糖、血脂常规检查也有助于诊断,但有200左右的NAFLD患者在确诊时,体重.血脂、血糖均在正常范围.     

Effects of probiotics on nonalcoholic fatty liver disease:A meta-analysis

AIM:To investigate the relationship between the gutliver axis and nonalcoholic fatty liver disease(NAFLD),we performed a meta-analysis to evaluate the effects of probiotic therapy in NAFLD.METHODS:We searched PubMed,Medline,Embase,Web of Science,the Cochrane Library and Chinese Biomedicine Database for all relevant randomized controlled trials on probiotics in patients with NAFLD/nonalcoholic steatohepatitis(NASH).A statistical analysis was performed using RevMan 5.0 software.RESULTS:Four randomized trials involving 134 NAFLD/NASH patients were included.The results showed that probiotic therapy signifcantly decreased alanine aminotransferase(ALT),aspartate transaminase(AST),total-cholesterol(T-chol),high density lipoprotein(HDL),tumor necrosis factor(TNF)-αand homeostasis model assessment of insulin resistance(HOMAIR)[ALT:weighted mean difference(WMD)-23.71,95%CI:-33.46--13.95,P<0.00001;AST:WMD-19.77,95%CI:-32.55--7.00,P=0.002;T-chol:WMD-0.28,95%CI:-0.55--0.01,P=0.04;HDL:WMD-0.09,95%CI:-0.16-0.01,P=0.03;TNF-α:WMD-0.32,95%CI:-0.48--0.17,P<0.0001;HOMA-IR:WMD-0.46,95%CI:-0.73--0.19,P=0.0008].However,the use of probiotics was not associated with changes in body mass index(BMI),glucose(GLU)and low density lipoprotein(LDL)(BMI:WMD 0.05,95%CI:-0.18-0.29,P=0.64;GLU:WMD 0.05,95%CI:-0.25-0.35,P=0.76;LDL:WMD-0.38,95%CI:-0.78-0.02,P=0.06).CONCLUSION:Probiotic therapies can reduce liver aminotransferases,total-cholesterol,TNF-αand improve insulin resistance in NAFLD patients.Modulation of the gut microbiota represents a new treatment for NAFLD.     

Metabolic aspects of adult patients with nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease(NAFLD) is a major cause of chronic liver disease and it encompasses a spectrum from simple steatosis to steatohepatitis, fibrosis, or cirrhosis. The mechanisms involved in the occurrence of NAFLD and its progression are probably due to a metabolic profile expressed within the context of a genetic predisposition and is associated with a higher energy intake. The metabolic syndrome(MS) is a cluster of metabolic alterations associated with an increased risk for the development of cardiovascular diseases and diabetes. NAFLD patients have more than one feature of the MS, and now they are considered the hepatic components of the MS. Several scientific advances in understanding the association between NAFLD and MS have identified insulin resistance(IR) as the key aspect in the pathophysiology of both diseases. In the multi parallel hits theory of NAFLD pathogenesis, IR was described to be central in the predisposition of hepatocytes to be susceptible to other multiple pathogenetic factors. The recent knowledge gained from these advances can be applied clinically in the prevention and management of NAFLD and its associated metabolic changes. The present review analyses the current literature and highlights the new evidence on the metabolic aspects in the adult patients with NAFLD.     

Nonalcoholic steatohepatitis in nonalcoholic fatty liver disease patients of Bangladesh

AIM: To explore the prevalence and risk factors for nonalcoholic steatohepatitis (NASH) in nonalcoholic fatty liver disease (NAFLD) patients. METHODS: We have included 493 patients with sonographic evidence of a fatty change, and 177 of these individuals were evaluated and confirmed after liver biopsy. The exclusion criteria consisted of significant alcohol abuse (< 20 g daily), evidence of hepatitis B and C, evidence of drug-induced fatty liver disease and other specific liver diseases such as hemochromatosis, Wilson’s disease or autoimmune liver disease. The patients were assessed for metabolic syndrome, and biochemical, anthropometric and histopathological evaluations were carried out. The degree of disease activity in the NAFLD patients was evaluated using the NAFLD Activity Score. The data were analyzed by SPSS, version 16.0. RESULTS: Females predominated among the study participants (250, 57.0%), and the mean age was 40.8 ± 10.2 years. The numbers of overweight, obeseⅠ and obese Ⅱ patients were 58 (13.2%), 237 (53.9%) and 93 (21.2%), respectively. However, there were 422 (96.2%) centrally obese patients. NASH was absent in 10 (5.6%) cases, borderline in 92 (52.6%) cases and present in 75 (42.4%) cases. The presence of diabetes could significantly (P = 0.001) differentiate NASH from simple steatosis. The following parameters did not influence the development of NASH: age, sex, basal metabolic index, waist circumference, serum high-density lipoprotein, triglyceride, insulin resistance index, hypertension and metabolic syndrome. The serum gammaglutamyl transpeptidase (GGT) level was significantly higher (P = 0.05, 51.7 ± 32.8 and 40.4 ± 22.6 U/L) in the NASH patients, with a sensitivity of 45% and a specificity of only 68%. The serum alanine aminotransferase and aspartate aminotransferase levels were not able to predict NASH. CONCLUSION: Females were the predominant sufferers of NAFLD in Bangladesh. The prevalence of NASH was high. Diabetes was found to be the main culprit in developing NASH. GGT was the only biochemical marker of NASH. We recommend liver biopsy in NAFLD patients who have diabetes and elevated GGT.     

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.     

Cytokeratin-18 fragments and biomarkers of the metabolic syndrome in nonalcoholic steatohepatitis

Nonalcoholic fatty liver disease （NAFLD） remains a leading cause of chronic liver disease. In the context of NAFLD, the presence of nonalcoholic steatohepatitis （NASH） portends an adverse prognosis with greater risk of liver fibrosis and cirrhosis. Although liver biopsy is the keystone of patient management in NAFLD, it is also increasingly clear that such evaluation has its limitations. The availability of biochemical markers of NAFLD and NASH has tremendous potential to radically alter management strategies for these conditions, as well as to monitor disease activity. Our article provides an overview of biomarker discovery and selection in the setting of NAFLD and highlights future directions in the field.