A previous trial compared 22 biopsy-proven NASH patients with 23 controls subjects and assessed gut overgrowth by (14)C-D-xylose and lactulose breath test, gut permeability by a dual lactulose-rhamnose sugar test, serum endotoxin levels by limulus amoebocyte lysate assay, and TNF-alpha levels by ELISA. Here, TNF is linked to metabolic dysfunction-associated steatohepatitis.