A-C) For these experiments, single-housed mice were treated 24 hrs ad libitum with antibiotics (ABX) or H2O for 2 wks prior to and throughout the 6 wks of DID except during the 2 hrs of ethanol exposure. Daily 20E consumption was measured and compared between groups. A) ABX-20E mice consumed significantly more ethanol than H2O-20E mice consistently throughout the 6 wks of the study. B) H2O and ABX groups that were not exposed to 20E did not significantly differ in the amount of H2O or ABX consumed during the 2 hrs of DID, and C) liver alcohol dehydrogenase (ADH) activity did not different between any of the groups at the conclusion of this experiment. D) In a separate cohort, 2 wks of ABX treatment did not significantly affect serum blood ethanol concentration (BEC) 45 mins following IP injection of ethanol (3.5 g/kg per mouse weight). Data are presented as Mean ± SEM, n=4–8/group; *p<0.05, **p<0.01.