Identification of Preclinical Biomarkers of Metabolic Dysfunction-Associated Steatotic Liver Disease versus Metabolic Dysfunction and Alcohol-Associated Liver Disease and the Impact of Diet.

Recent diagnostic advancements have defined metabolic dysfunction-associated steatotic liver disease (MASLD) and increased alcohol intake (MetALD) in cases of alcohol consumption ≥20 g/day in females and >30 g/day, in males. While current treatments can modify dietary behavior or treat organ-specific pathology, they have limited efficacy. There is a need for a preclinical animal model of MetALD that can assess concurrent diet and alcohol consumption on organ pathology to inform treatment strategies. Male C57BL/6J mice were randomly assigned to the following six dietary groups for 13 weeks: ±chow diet (CD), ±high-fat diet (HFD), and water or 10% (v/v) ethanol. Glucose tolerance test was performed at week 10. Physiological parameters were assessed, and cecal 16S rRNA and liver mRNA sequencing was conducted. 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 further modulated with CD. Kupffer cell markers were lower in HFD + ethanol mice relative to those in other groups. Diet and ethanol had distinct physiological effects in this MetALD model. Mice on CD + HFD had worsened metabolic syndrome, but improved liver injury and microbiome diversity compared with mice on HFD. Hepatic gene markers and microbiome changes of MASLD were identified. This preclinical model may help identify novel therapeutics to treat MASLD and MetALD.