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The term, gut–liver axis, is used to highlight the close anatomical and functional relationship between the intestine and the liver. It has been increasingly recognized that the gut–liver axis plays an essential role in the development and progression of liver disease. In particular, in non‐alcoholic fatty liver disease and alcohol‐related liver disease, the two most common causes of chronic liver disease, a dysbiotic gut microbiota can influence intestinal permeability, allowing some pathogens or bacteria‐derived factors from the gut reaching the liver through the enterohepatic circulation contributing to liver injury, steatohepatitis, and fibrosis progression. Pathways involved are multiple, including changes in bile acid metabolism, intestinal ethanol production, generation of short‐chain fatty acids, and other by‐products. Bile acids act through dedicated bile acid receptors, farnesoid X receptor and TGR5, in both the ileum and the liver, influencing lipid metabolism, inflammation, and fibrogenesis. Currently, both non‐alcoholic fatty liver disease and alcohol‐related liver disease lack effective therapies, and therapeutic targeting of gut microbiota and bile acids enterohepatic circulation holds promise. In this review, we summarize current knowledge about the role of gut microbiota in the pathogenesis of non‐alcoholic fatty liver disease and alcohol‐related liver disease, as well as the relevance of microbiota or bile acid‐based approaches in the management of those liver diseases.

Background and Aims Interleukin‐22 has beneficial effects on inflammation and impaired hepatic regeneration that characterize alcohol‐associated hepatitis (AH). F‐652 is a recombinant fusion protein of human interleukin‐22 and immunoglobulin G2 fragment crystallizable. This study aims to assess the safety and efficacy signals of F‐652 in patients with moderate and severe AH. Approach and Results A phase‐2 dose‐escalating study was carried out. F‐652 (10 μg/kg, 30 μg/kg, or 45 μg/kg) administered on days 1 and 7 was tested in 3 patients each with moderate (Model for End‐Stage Liver Disease [MELD] scores: 11‐20) and severe AH (MELD scores: 21‐28). Safety was defined by absence of serious adverse events and efficacy was assessed by Lille score, changes in MELD score, and serum bilirubin and aminotransferases at days 28 and 42. Three independent propensity‐matched comparator patient cohorts were used. Plasma extracellular vesicles and multiplex serum cytokines were measured to assess inflammation and hepatic regeneration. Eighteen patients (9 moderate and 9 severe AH) were enrolled, 66% were male, and the mean age was 48 years. The half‐life of F‐652 following the first dose was 61‐85 hours. There were no serious adverse events leading to discontinuation. The MELD score and serum aminotransferases decreased significantly at days 28 and 42 from baseline (P < 0.05). Day‐7 Lille score was 0.45 or less in 83% patients as compared with 6%, 12%, and 56% among the comparator cohorts. Extracellular vesicle counts decreased significantly at day 28 (P < 0.013). Cytokine inflammatory markers were down‐regulated, and regeneration markers were up‐regulated at days 28 and 42. Conclusions F‐652 is safe in doses up to 45 μg/kg and associated with a high rate of improvement as determined by Lille and MELD scores, reductions in markers of inflammation and increases in markers of hepatic regeneration. This study supports the need for randomized placebo‐controlled trials to test the efficacy of F‐652 in AH.

Liver transplantation (LT) for alcohol associated hepatitis (AH) remains controversial. We convened a consensus conference to examine various aspects of LT for AH. The goal was not to unequivocally endorse LT for AH; instead, it was to propose recommendations for programs that perform or plan to perform LT for AH. Criteria were established to determine candidacy for LT in the setting of AH and included the following: (1) AH patients presenting for the first time with decompensated liver disease that are nonresponders to medical therapy without severe medical or psychiatric comorbidities; (2) a fixed period of abstinence prior to transplantation is not required; and (3) assessment with a multidisciplinary psychosocial team, including a social worker and an addiction specialist/mental health professional with addiction and transplantation expertise. Supporting factors included lack of repeated unsuccessful attempts at addiction rehabilitation, lack of other substance use/dependency, acceptance of diagnosis/insight with a commitment of the patient/family to sobriety, and formalized agreement to adhere to total alcohol abstinence and counseling. LT should be avoided in AH patients who are likely to spontaneously recover. Short‐term and longterm survival comparable to other indications for LT must be achieved. There should not be further disparity in LT either by indication, geography, or other sociodemographic factors. Treatment of alcohol‐use disorders should be incorporated into pre‐ and post‐LT care. The restrictive and focused evaluation process described in the initial LT experience for AH worldwide may not endure as this indication gains wider acceptance at more LT programs. Transparency in the selection process is crucial and requires the collection of objective data to assess outcomes and minimize center variation in listing. Oversight of program adherence is important to harmonize listing practices and outcomes.

AbstractNeutrophil extracellular traps, or NETs, are heterogenous, filamentous structures which consist of extracellular DNA, granular proteins, and histones. NETs are extruded by a neutrophil in response to various stimuli. Although NETs were initially implicated in immune defense, subsequent studies have implicated NETs in a spectrum of disease processes, including autoimmune disease, thrombosis, and cancer. NETs also contribute to the pathogenesis of several common liver diseases, including alcohol-associated liver disease and portal hypertension. Although there is much interest in the therapeutic potential of NET inhibition, future clinical applications must be balanced against potential increased risk of infection.

Disease monitoring in nonalcoholic steatohepatitis (NASH) is limited by absence of noninvasive biomarkers of disease regression or progression. We aimed to examine the role of multiparametric three‐dimensional magnetic resonance elastography (3D‐MRE) and magnetic resonance imaging proton density fat fraction (MRI‐PDFF) in the detection of NASH regression after interventions. This is a single‐center prospective clinical trial of 40 patients who underwent bariatric surgery. Imaging and liver biopsies were obtained at baseline and 1 year after surgery. The imaging protocol consisted of multifrequency 3D‐MRE to determine the shear stiffness at 60 Hz and damping ratio at 40 Hz, and MRI‐PDFF to measure the fat fraction. A logistic regression model including these three parameters was previously found to correlate with NASH. We assessed the model performance in the detection of NASH resolution after surgery by comparing the image‐predicted change in NAFLD activity score (delta NAS) to the histologic changes. A total of 38 patients (median age 43, 87% female, 30 of 38 with NAS ≥ 1, and 13 of 38 with NASH) had complete data at 1 year. The NAS decreased in all subjects with NAS ≥ 1 at index biopsy, and NASH resolved in all 13. There was a strong correlation between the predicted delta NAS by imaging and the delta NAS by histology (r = 0.73, P < 0.001). The strength of correlation between histology and the predicted delta NAS using single conventional parameters, such as the fat fraction by MRI‐PDFF or shear stiffness at 60 Hz by MRE, was r = 0.69 (P < 0.001) and r = 0.43 (P = 0.009), respectively. Conclusion: Multiparametric 3D‐MRE and MRI‐PDFF can detect histologic changes of NASH resolution after bariatric surgery. Studies in a nonbariatric setting are needed to confirm the performance as a composite noninvasive biomarker for longitudinal NASH monitoring.

Pharmacologic stimulation of a G protein–coupled receptor preferentially expressed on fibroblasts reverses experimental lung and liver fibrosis.

OBJECTIVES: Alcohol-associated liver disease is increasing, especially hospitalizations with acute on chronic liver failure and need for liver transplant. We examined trends in prevalence, inhospital mortality, and resource utilization associated with AALD and ACLF in the young. METHODS: The National Inpatient Sample (2006–2014) was queried for hospitalizations with a discharge diagnosis of cirrhosis using the International Classification of Diseases, Ninth Edition, codes. ACLF hospitalization was defined as ≥2 organ failures and stratified by age: young (≤35 years) and older (>35 years). RESULTS: Of 447,090 AALD admissions (16,126 in young) between 2006 and 2014, ACLF occurred in 29,599 (6.6%), of which 1,143 (7.1%) were in young. Compared with older, admissions in young had more women (35% vs 29%), were obese (11% vs 7.6%), were Hispanics (29% vs 18%), have alcoholic hepatitis (AH) (41% vs 17%), and have ACLF grades 2 or 3 (34% vs 25%), P < 0.001 for all. Between 2006 and 2014, ACLF in AALD among young increased from 2.8% to 5.2%, with an AH proportion from 24% to 42%, P < 0.0001 for both. Young had more complications requiring ventilation (79% vs 76%) and dialysis (32% vs 28%), P < 0.001 for both. Compared with older, ACLF admission in young had longer hospitalization (12 vs 10 days) with higher hospital charges ($127,915 vs $97,511), P < 0.0001 for both, with 20% reduced inhospital mortality (54%–45%), P < 0.001. DISCUSSION: AALD-related hospitalizations are increasing in young in the United States, mainly because of the increasing frequency of AH. Furthermore, this disease burden in young is increasing with a higher frequency of admissions with more severe ACLF and consumption of hospital resources. Studies are needed to develop preventive strategies to reduce burden related to AALD and ACLF in young.