Conventional (Conv; n=8–15) and germ-free C57BL/6 mice (GF; n=8–16) were gavaged with ethanol (300μl, 30% vol/vol) or an isocaloric amount of dextrose (300μl, 0.42g/ml) once, and harvested after 9 h. (A) Plasma ethanol levels. (B) Hepatic mRNA levels of Adh1, and liver ADH activity. (C) Hepatic mRNA levels of Cat. (D) Hepatic mRNA levels of Cyp2e1, and immunoblot analysis and quantification of liver CYP2E1 (n=5–8). (E) Hepatic mRNA levels of Aldh2. *p<0.05.