(A–C) Oral vancomycin does not affect weight gain, % body fat, or % lean body mass or body composition after 50% small bowel resection(SBR). *p<0.01, **p=0.03 (D) Mice demonstrate a significant decrease in percent lean mass after SBR regardless of vancomycin treatment. Mice treated with vancomycin demonstrated a marginally significant 1.2% decrease in fat at 5 weeks after SBR, while the control mice demonstrated a significant increase in fat at 5 weeks post operatively. There was no significant difference between percent fat or lean mass between the control groups at either time point. #p<0.01, *p<0.05, bar= not significant