MicroRNA and Protein Biomarkers of Intestinal Permeability in the Assessment of Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD)

Intestinal barrier dysfunction and microRNA dysregulation are proposed contributors to progression of metabolic dysfunction-associated steatotic liver disease (MASLD). We aimed to assess selected protein and miRNA biomarkers of intestinal permeability in relation to MASLD severity. We included 104 patients with MASLD and 57 healthy controls. Serum lipopolysaccharide-binding protein (LBP), diamine oxidase (DAO), tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6), and miRNAs (miR-21, miR-29a, miR-122) were measured. Multivariable logistic regression identified independent predictors of steatosis and fibrosis severity. Patients with MASLD showed higher LBP levels (<i>p</i> = 0.002) and increased serum miR-122 expression (<i>p</i> < 0.0001) compared with controls. LBP correlated with CAP values (Rho = 0.23, <i>p</i> = 0.02) and was elevated in advanced steatosis (<i>p</i> = 0.04). DAO levels correlated with CAP (Rho = 0.22, <i>p</i> = 0.02) and were higher in advanced steatosis (<i>p</i> = 0.04) but decreased in advanced fibrosis (<i>p</i> = 0.04). MiR-122 correlated with fibrosis indices (TE: Rho = 0.22, <i>p</i> = 0.03; APRI: Rho = 0.41, <i>p</i> = 0.0001) and liver enzymes (ALT: Rho = 0.40, AST: Rho = 0.50, both <i>p</i> < 0.0001). Logistic regression identified elevated miR-122 and reduced miR-21 as independent predictors of MASLD, while DAO and transaminases predicted advanced steatosis. Elevated serum miR-122, alongside reduced miR-21, independently predict MASLD. DAO is associated with steatosis severity, while miR-122 reflects fibrotic progression.