Identification of Preclinical Biomarkers of Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD) versus MASLD and Increased Alcohol Intake and the Impact of Diet.

Recent diagnostic advancements have characterized metabolic dysfunction-associated steatotic liver disease (MASLD) and increased alcohol intake (MetALD) if alcohol consumption is ≥ 20 or 30 g/d, females and males, respectively. Available treatments may affect dietary behavior or treat organ pathology but have limited effectiveness. There is a preclinical need for an animal model of MetALD that can assess concurrent diet and alcohol consumption on organ pathology to establish treatment strategies. Male, C57BL/6J mice were randomly assigned to six dietary groups for 13 weeks containing the following: ±chow diet (CD), ±high-fat diet (HFD), and water or 10% (v/v) ethanol. Glucose tolerance testing was performed at week 10. Physiological measures were assessed, and cecal 16S rRNA and liver mRNA sequencing were performed. HFD + ethanol (MetALD) mice had exacerbated dyslipidemia and gut dysbiosis relative to HFD + water (MASLD) mice. CD + HFD + ethanol mice had reduced glucagon-like peptide-1 relative to HFD + ethanol mice. MASLD and MetALD mice had altered transcription factor regulatory networks, which were altered with CD access. Kupffer cell markers are lower in HFD + ethanol mice relative to other groups. Diet and ethanol have distinct physiological effects in this MetALD model. Mice provided CD + HFD had worsened metabolic syndrome, but improved liver injury and microbiome diversity compared with HFD mice. Hepatic gene markers and microbiome changes of MASLD were identified. This preclinical model helps identify novel therapeutics to treat MASLD and MetALD.