Background & aims Alcohol use disorder (AUD) represents the most common cause of liver disease. The gut microbiota plays a critical role in the progression of alcohol‐related liver damage. Aim of this study was to characterize the gut microbial composition and function in AUD patients with alcohol‐associated liver disease (AALD). Methods This study included 36 AUD patients (14 with cirrhosis) who were active drinkers and an equal number of matched controls. Stool microbial composition, serum levels of lipopolysaccharide, cytokines/chemokines and gut microbiota functional profile were assessed. Results AUD patients had a decreased microbial alpha diversity as compared to controls (0.092 vs 0.130, P = .047) and a specific gut microbial signature. The reduction of Akkermansia and the increase in Bacteroides were able to identify AUD patients with an accuracy of 93.4%. Serum levels of lipopolysaccharide (4.91 vs 2.43, P = .009) and pro‐inflammatory mediators (tumour necrosis factor alpha 60.85 vs 15.08, P = .001; interleukin [IL] 1beta 4.43 vs 1.72, P = .0001; monocyte chemoattractant protein 1 225.22 vs 16.43, P = .006; IL6 1.87 vs 1.23, P = .008) were significantly increased in AUD patients compared to controls and in cirrhotic patients compared to non‐cirrhotic ones (IL6 3.74 vs 1.39, P = .019; IL8 57.60 vs 6.53, P = .004). The AUD‐associated gut microbiota showed an increased expression of gamma‐aminobutyric acid (GABA) metabolic pathways and energy metabolism. Conclusions AUD patients present a specific gut microbial fingerprint, associated with increased endotoxaemia, systemic inflammatory status and functional alterations that may be involved in the progression of the AALD and in the pathogenesis of AUD.

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Alcohol Use Disorder (AUD) is a chronic and relapsing condition characterized by harmful alcohol intake and behavioral-cognitive changes. AUD is the most common cause of liver disease in the Western world. Alcohol abstinence is the cornerstone of therapy in alcoholic patients affected with liver disease. Medical recommendations, brief motivational interventions and psychosocial approach are essential pieces of the treatment for these patients; however, their efficacy alone may not be enough to achieve total alcohol abstinence. The addition of pharmacological treatment could improve clinical outcomes in AUD patients. Moreover, pharmacological treatments for AUD are limited in patients with advanced liver disease, since impaired liver function affects drugs metabolism and could increase the risk of drugs-related hepatotoxicity. At present, only baclofen has been tested in RCTs in patients with advanced liver disease. This medication was effective to reduce alcohol intake, to promote alcohol abstinence and to prevent relapse in AUD patients affected by liver cirrhosis. In addition, the drug showed a safe profile in these patients. In this review, clinical studies about efficacy and safety of baclofen administration in patients with AUD and advanced liver disease will be reviewed. Open question about the most appropriate dose of the drug, duration of the treatment and need of additional studies will also be discussed.

Background: There is strong evidence that alcoholism leads to dysbiosis in both humans and animals. However, it is unclear how changes in the intestinal microbiota (IM) relate to ethanol (EtOH)induced disruption of gut-liver homeostasis. We investigated this issue using selectively bred Sardinian alcohol-preferring (sP) rats, a validated animal model of excessive EtOH consumption.Methods: Independent groups of male adult sP rats were exposed to the standard, home-cage 2-bottle "EtOH (10% v/v) versus water" choice regimen with unlimited access for 24 h/d (Group Et) for 3 (T1), 6 (T2), and 12 (T3) consecutive months. Control groups (Group Ct) were composed of matchedage EtOH-na€ ıve sP rats. We obtained samples from each rat at the end of each experimental time, and we used blood and colon tissues for intestinal barrier integrity and/or liver pathology assessments and used stool samples for IM analysis with 16S ribosomal RNA gene sequencing.Results: Rats in Group Et developed hepatic steatosis and elevated serum transaminases and endotoxin/lipopolysaccharide (LPS) levels but no other liver pathological changes (i.e., necrosis/inflammation) or systemic inflammation. While we did not find any apparent alteration of the intestinal colonic mucosa, we found that rats in Group Et exhibited significant changes in IM composition compared to the rats in Group Ct. These changes were sustained throughout T1, T2, and T3. In particular, Ruminococcus, Coprococcus, and Streptococcus were the differentially abundant microbial genera at T3. The KEGG Ortholog profile revealed that IM functional modules, such as biosynthesis, transport, and export of LPS, were also enriched in Group Et rats at T3.Conclusions: We showed that chronic, voluntary EtOH consumption induced liver injury and endotoxemia together with dysbiotic changes in sP rats. This work sets the stage for improving our knowledge of the prevention and treatment of EtOH-related diseases.