Effect of Antibiotics on Bacterial Flora of Rats with Intestinal Blind Loops 1

Summary

Rats with weight loss resulting from surgically created self-filling upper small intestinal blind loops had increased numbers of Escherichia coli and bacteroides in the blind loop, mid-small intestine, and cecum. Counts of other organisms were not significantly elevated. Treatment with neomycin-polymyxin-bacitracin or lincomycin resulted in weight gain, reduced fecal fat excretion, and reduction of bacteroides but not E. coli counts in the blind loop and small intestine. Mixed cultures from blind loops of untreated rats and isolates of bacteroides decon-jugated glycocholic acid in vitro, while mixed cultures from blind loops of treated rats or small intestine of normal rats and isolates of E. coli did not. The findings suggest that bacteroides are the important organisms producing steatorrhea in the rat blind-loop syndrome.