The intestinal microbiota and TLR4 promote hepatocellular carcinoma (HCC) development in chronically injured livers. TLR4 activation in non-bone marrow-derived liver cells is essential for HCC promotion, but not for initiation. Gut sterilization or TLR4 inactivation significantly reduces HCC development, suggesting these factors are therapeutic targets for HCC prevention in advanced liver disease. The intestinal microbiota and TLR4 contribute to HCC by increasing cell proliferation, epiregulin expression, and preventing apoptosis. TLR4 and the microbiota also suppress apoptosis in late-stage HCC, highlighting their role in tumor progression. The study demonstrates that TLR4 signaling in resident liver cells, particularly hepatic stellate cells, mediates tumor promotion through growth factor secretion and anti-apoptotic signals. These findings suggest that targeting the intestinal microbiota and TLR4 could be a promising strategy for HCC prevention and treatment.The intestinal microbiota and TLR4 promote hepatocellular carcinoma (HCC) development in chronically injured livers. TLR4 activation in non-bone marrow-derived liver cells is essential for HCC promotion, but not for initiation. Gut sterilization or TLR4 inactivation significantly reduces HCC development, suggesting these factors are therapeutic targets for HCC prevention in advanced liver disease. The intestinal microbiota and TLR4 contribute to HCC by increasing cell proliferation, epiregulin expression, and preventing apoptosis. TLR4 and the microbiota also suppress apoptosis in late-stage HCC, highlighting their role in tumor progression. The study demonstrates that TLR4 signaling in resident liver cells, particularly hepatic stellate cells, mediates tumor promotion through growth factor secretion and anti-apoptotic signals. These findings suggest that targeting the intestinal microbiota and TLR4 could be a promising strategy for HCC prevention and treatment.