Summary Background The bile acid derivative 6-ethylchenodeoxycholic acid (obeticholic acid) is a potent activator of the farnesoid X nuclear receptor that reduces liver fat and fibrosis in animal models of fatty liver disease. We assessed the efficacy of obeticholic acid in adult patients with non-alcoholic steatohepatitis. Methods We did a multicentre, double-blind, placebo-controlled, parallel group, randomised clinical trial at medical centres in the USA in patients with non-cirrhotic, non-alcoholic steatohepatitis to assess treatment with obeticholic acid given orally (25 mg daily) or placebo for 72 weeks. Patients were randomly assigned 1:1 using a computer-generated, centrally administered procedure, stratified by clinical centre and diabetes status. The primary outcome measure was improvement in centrally scored liver histology defined as a decrease in non-alcoholic fatty liver disease activity score by at least 2 points without worsening of fibrosis from baseline to the end of treatment. A planned interim analysis of change in alanine aminotransferase at 24 weeks undertaken before end-of-treatment (72 weeks) biopsies supported the decision to continue the trial (relative change in alanine aminotransferase −24%, 95% CI −45 to −3). A planned interim analysis of the primary outcome showed improved efficacy of obeticholic acid (p=0·0024) and supported a decision not to do end-of-treatment biopsies and end treatment early in 64 patients, but to continue the trial to obtain the 24-week post-treatment measures. Analyses were done by intention-to-treat. This trial was registered with ClinicalTrials.gov, number NCT01265498. Findings Between March 16, 2011, and Dec 3, 2012, 141 patients were randomly assigned to receive obeticholic acid and 142 to placebo. 50 (45%) of 110 patients in the obeticholic acid group who were meant to have biopsies at baseline and 72 weeks had improved liver histology compared with 23 (21%) of 109 such patients in the placebo group (relative risk 1·9, 95% CI 1·3 to 2·8; p=0·0002). 33 (23%) of 141 patients in the obeticholic acid developed pruritus compared with nine (6%) of 142 in the placebo group. Interpretation Obeticholic acid improved the histological features of non-alcoholic steatohepatitis, but its long-term benefits and safety need further clarification. Funding National Institute of Diabetes and Digestive and Kidney Diseases, Intercept Pharmaceuticals.

Background Liver fibrosis is the most important predictor of mortality in nonalcoholic fatty liver disease (NAFLD). Quantitative risk of mortality by fibrosis stage has not been systematically evaluated. We aimed to quantify the fibrosis stage-specific risk of all-cause and liver-related mortality in NAFLD. Methods Through a systematic review and meta-analysis, we identified 5 adult NAFLD cohort studies reporting fibrosis stage specific mortality (0–4). Using fibrosis stage 0 as a reference population, fibrosis stage-specific mortality rate ratios (MRR) with 95% confidence intervals (CI), for all-cause and liver-related mortality, were estimated. The study is reported according to the PRISMA statement. Results 1,495 NAFLD patients with 17,452 patient years of follow-up were included. Compared to NAFLD patients with no fibrosis (stage 0), NAFLD patients with fibrosis were at an increased risk for all-cause mortality and this risk increased with increase in the stage of fibrosis: stage 1, MRR, 1.58 (95% CI 1.19–2.11); stage 2, MRR, 2.52 (95% CI 1.85–3.42); stage 3, MRR, 3.48 (95% CI 2.51–4.83), and stage 4, MRR, 6.40 (95% CI 4.11–9.95). The results were more pronounced as the risk of liver-related mortality increased exponentially with increase in the stage of fibrosis: stage 1, MRR, 1.41 (95% CI 0.17–11.95); stage 2, MRR, 9.57 (95% CI 1.67–54.93); stage 3, MRR, 16.69 (95% CI 2.92–95.36); and stage 4, MRR, 42.30 (95% CI 3.51–510.34). Limitations Inability to adjust for co-morbid conditions or demographics known to impact fibrosis progression in NAFLD, and the inclusion of patients with simple steatosis and NASH without fibrosis in the reference comparison group. Conclusion The risk of liver-related mortality increases exponentially with increase in fibrosis stage. These data have important implications in assessing utility of each stage and benefits of regression of fibrosis from one stage to another.

Nonalcoholic fatty liver disease (NAFLD) and resulting nonalcoholic steatohepatitis (NASH) are highly prevalent in the United States, where they are a growing cause of cirrhosis and hepatocellular carcinoma (HCC) and increasingly an indicator for liver transplantation. A Markov model was used to forecast NAFLD disease progression. Incidence of NAFLD was based on historical and projected changes in adult prevalence of obesity and type 2 diabetes mellitus (DM). Assumptions were derived from published literature where available and validated using national surveillance data for incidence of NAFLD‐related HCC. Projected changes in NAFLD‐related cirrhosis, advanced liver disease, and liver‐related mortality were quantified through 2030. Prevalent NAFLD cases are forecasted to increase 21%, from 83.1 million (2015) to 100.9 million (2030), while prevalent NASH cases will increase 63% from 16.52 million to 27.00 million cases. Overall NAFLD prevalence among the adult population (aged ≥15 years) is projected at 33.5% in 2030, and the median age of the NAFLD population will increase from 50 to 55 years during 2015‐2030. In 2015, approximately 20% of NAFLD cases were classified as NASH, increasing to 27% by 2030, a reflection of both disease progression and an aging population. Incidence of decompensated cirrhosis will increase 168% to 105,430 cases by 2030, while incidence of HCC will increase by 137% to 12,240 cases. Liver deaths will increase 178% to an estimated 78,300 deaths in 2030. During 2015‐2030, there are projected to be nearly 800,000 excess liver deaths. Conclusion: With continued high rates of adult obesity and DM along with an aging population, NAFLD‐related liver disease and mortality will increase in the United States. Strategies to slow the growth of NAFLD cases and therapeutic options are necessary to mitigate disease burden. (Hepatology 2018;67:123‐133).

NAFLD is a clinical syndrome characterized by predominant macrovesicular steatosis of the liver. The clinical and histological phenotypes of NAFLD extend from a nonalcoholic fatty liver to NASH. Although the prevalence of NAFLD is increasing globally, and it is set to become the predominant cause of chronic liver disease in many parts of the world, the epidemiology and demographic characteristics of NAFLD vary worldwide. Indeed, the condition is associated with obesity and insulin resistance in most cases in the Western world, but the disease manifests at a lower BMI in Asian countries and many patients do not seem to have insulin resistance as determined using conventional methods. The similarities and differences in the epidemiology of NAFLD in different regions of the world are discussed and the potential role of genetics and insulin resistance in disease progression is also presented.

Nonalcoholic fatty liver disease (NAFLD) is estimated to afflict approximately 1 billion individuals worldwide. In a subset of NAFLD patients, who have the progressive form of NAFLD termed nonalcoholic steatohepatitis (NASH), it can progress to advanced fibrosis, cirrhosis, hepatocellular carcinoma, and liver-related morbidity and mortality. NASH is typically characterized by a specific pattern on liver histology, including steatosis, lobular inflammation, and ballooning with or without peri-sinusoidal fibrosis. Thus, key issues in NAFLD patients are the differentiation of NASH from simple steatosis and identification of advanced hepatic fibrosis. Until now, liver biopsy has been the gold standard for identifying these 2 critical end points, but has well-known limitations, including invasiveness; rare but potentially life-threatening complications; poor acceptability; sampling variability; and cost. Furthermore, due to the epidemic proportion of individuals with NAFLD worldwide, liver biopsy evaluation is impractical, and noninvasive assessment for the diagnosis of NASH and fibrosis is needed. Although much of the work remains to be done in establishing cost-effective strategies for screening for NASH, advanced fibrosis, and cirrhosis, in this review, we summarize the current state of the noninvasive assessment of liver disease in NAFLD, and we provide an expert synthesis of how these noninvasive tools could be utilized in clinical practice. Finally, we also list the key areas of research priorities in this area to move forward clinical practice.

In the past decade, an exciting realization has been that diverse liver diseases - ranging from nonalcoholic steatohepatitis, alcoholic steatohepatitis and cirrhosis to hepatocellular carcinoma - fall along a spectrum. Work on the biology of the gut-liver axis has assisted in understanding the basic biology of both alcoholic fatty liver disease and nonalcoholic fatty liver disease (NAFLD). Of immense importance is the advancement in understanding the role of the microbiome, driven by high-throughput DNA sequencing and improved computational techniques that enable the complexity of the microbiome to be interrogated, together with improved experimental designs. Here, we review gut-liver communications in liver disease, exploring the molecular, genetic and microbiome relationships and discussing prospects for exploiting the microbiome to determine liver disease stage and to predict the effects of pharmaceutical, dietary and other interventions at a population and individual level. Although much work remains to be done in understanding the relationship between the microbiome and liver disease, rapid progress towards clinical applications is being made, especially in study designs that complement human intervention studies with mechanistic work in mice that have been humanized in multiple respects, including the genetic, immunological and microbiome characteristics of individual patients. These 'avatar mice' could be especially useful for guiding new microbiome-based or microbiome-informed therapies.

SUMMARY The presence of advanced fibrosis in nonalcoholic fatty liver disease (NAFLD) is the most important predictor of liver mortality. There are limited data on the diagnostic accuracy of gut microbiota derived signature for predicting the presence of advanced fibrosis. In this prospective study, we characterized the gut microbiome compositions using whole-genome shotgun sequencing of DNA extracted from stool samples. This study included 86 uniquely well-characterized patients with biopsy-proven NAFLD, 72 of which had mild/moderate (stage 0–2 fibrosis) NAFLD, and 14 had advanced fibrosis (stage 3 or 4 fibrosis). We identified a set of forty features (p-value <0.006), which included 37 bacterial species that were used to construct a Random Forest classifier model to distinguish mild/moderate NAFLD from advanced fibrosis. The model had a robust diagnostic accuracy (AUC 0.936) for detecting advanced fibrosis. This study provides preliminary evidence for a novel fecal-microbiome derived metagenomic signature to detect advanced fibrosis in NAFLD.

Background: Nonalcoholic fatty liver disease (NAFLD) with resulting nonalcoholic steatohepatitis (NASH) are increasingly a cause of cirrhosis and hepatocellular carcinoma (HCC) globally. This burden is expected to increase as epidemics of obesity, diabetes and metabolic syndrome continue to grow. The goal of this analysis was to use a Markov model to forecast NAFLD disease burden using currently available data. Methods:A model was used to estimate NAFLD and NASH disease progression in 8 countries based on data for adult prevalence of obesity and type 2 diabetes mellitus (DM). Published estimates and expert consensus were used to build and validate the model projections. Results:If obesity and DM level off in the future, we project a modest growth in total NAFLD cases (0-30%), between 2016-2030, with the highest growth in China as result of urbanization and the lowest growth in Japan as result of a shrinking population.However, at the same time, NASH prevalence will increase 15-56%, while liver mortality and advanced liver disease will more than double as result of an aging/increasing population.Conclusions: NAFLD and NASH represent a large and growing public health problem and efforts to understand this epidemic and to mitigate the disease burden are needed.If obesity and DM continue to increase at current and historical rates, both NAFLD and 4 NASH prevalence are expected to increase. Since both are reversible, public health campaigns to increase awareness and diagnosis, and to promote diet and exercise can help manage the growth in future disease burden.Lay summary: Nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) can lead to advanced liver disease, and are occurring in increasing numbers in tandem with epidemics of obesity and diabetes. A mathematical model was built to understand how the disease burden associated with NAFLD and NASH will change over time. Results suggest increasing numbers of cases of advanced liver disease and liver-related mortality in the coming years. 5 BACKGROUNDNonalcoholic fatty liver disease (NAFLD) is a leading cause of liver disease globally [1][2][3]. This condition is characterized by excess liver fat in the absence of other causes such as alcohol consumption [4,5]. Obesity, type 2 diabetes mellitus (DM) and metabolic syndrome (MetS) are consistently identified as the most important risk factors for NAFLD [4,6].In order to classify the population, NAFLD may be divided into two groups: NAFL (steatosis only) or NASH (nonalcoholic steatohepatitis), where steatosis is accompanied by inflammation and ballooning. NASH frequently progresses to liver fibrosis [7] that is the main risk factor for liver-related mortality [8]. Odds of progression to advanced liver disease, including hepatic decompensation and hepatocellular carcinoma (HCC), are higher among those with NASH compared to those with NAFL [7]. Increasing age, obesity, DM and the presence of NASH have been consistently identified as risk factors for progression to cirrhosis [6,9].There is a...