CD8A and hepatocellular carcinoma: On the protective signals side, acetate from Bifidobacterium pseudolongum activates GPR43 and suppresses IL-6/JAK1/STAT3 signaling, and alleviates NAFLD-HCC–prone inflammatory tone, while Bacteroides thetaiotaomicron-derived acetate promotes M1 macrophage polarization and enhances CD8+ T-cell function in the liver [81, 192].