Metabolic dysfunction-associated steatohepatitis (MASH) is a progressive liver disease that can lead to fibrosis, cirrhosis, and hepatocellular carcinoma. Though MASH is closely tied to metabolic risk factors, the underlying pathogenic mechanisms remain scarcely understood. Recent research has emphasized the importance of the gut-liver axis in its pathogenesis, an aspect less explored in human studies. Here, we investigated whether the duodenal epithelium of MASH patients could exhibit intrinsic dysfunctions.