This study indicated (1) that changes in the nutritional status of the liver in rats fed a HF diet may cause adverse effects due to reduced expression of CYP1A1, CYP1A2, and CYP2E1, in addition to adverse effects of lipid-lowering drugs such as fluvastatin and (2) that intake of dietary inulin alone suppressed the development of hepatic steatosis and ameliorated the nutritional status, followed by a suppression of the reduction in hepatic expression of drug-metabolizing enzymes such as CYP1A1, CYP1A2, and CYP2E1, while co-treatment with statin had slightly additive or synergistic effects. The gene discussed is CYP1A1; the disease is Hepatic steatosis.