Related Experiment Video
Updated: May 8, 2026

Mouse Model of Metabolic Dysfunction-Associated Steatotic Liver Disease with Fibrosis
Published on: July 18, 2025
Faecal Cathepsin B and S Are Associated With Liver Disease Severity and Adiposity in MASLD
Aenne Harberts1,2, Marcos F Fondevila1, Henriette Kreimeyer1,3
1Department of Medicine, University of California San Diego, La Jolla, California, USA.
Background & Aims:
Dysregulation of hepatic cathepsins contributes to metabolic dysfunction-associated steatotic liver disease (MASLD) by promoting inflammation, apoptosis, and fibrosis. However, the role of intestinal cathepsins in MASLD has not been investigated. Given the central role of the gut-liver axis in disease progression, this represents an important knowledge gap.
Methods:
Faecal cathepsin B and S activity was measured in 95 patients with MASLD and 18 healthy controls. Cathepsin activity was correlated with liver disease severity, metabolic parameters, and gut microbiome composition.
Results:
Faecal cathepsin B and S activity was higher in patients with MASLD than in healthy controls. Cathepsin B activity was further increased in patients with metabolic dysfunction-associated steatohepatitis. Cathepsin B and S activity correlated with serum transaminases and hepatic steatosis, while cathepsin B activity was additionally associated with liver stiffness. Cathepsin B and S activity correlated with adiposity but showed no associations with other metabolic dysfunction-related parameters. Moreover, gut microbiome composition differed between patients with low vs. high faecal cathepsin B or S activity, respectively.
Conclusion:
Increased faecal cathepsin B and S activity is associated with liver disease severity and adiposity in MASLD and is linked to alterations of the gut microbiome, suggesting a potential role of intestinal cathepsins in gut-liver axis dysfunction.
