As a proof of principle, microbial genes involved in SCFA synthesis, e.g., pyruvate carboxylase, phosphate acetyltransferase, and phosphate butyryltransferase, as well as fecal levels of oxaloacetate and acetylphosphate, which are known SCFA intermediates, were overexpressed in NAFLD-HCC compared to NAFLD-cirrhosis and non-NAFLD, demonstrating HCC specificity that could be exploited for the discovery of non-invasive biomarkers. This evidence concerns the gene PC and hepatocellular carcinoma.