Probiotic Lactobacillus reuteri Ameliorates Disease Due to Enterohemorrhagic Escherichia coli in Germfree Mice

Strains of enterohemorrhagic Escherichia coli (EHEC) are a group of Shiga toxin-producing food-borne pathogens that cause severe hemorrhagic colitis and can lead to hemolytic-uremic syndrome (HUS), a life-threatening condition that principally affects children and for which there is no effective treatment. We used a germfree mouse model of renal and enteric disease due to EHEC to determine if probiotic Lactobacillus reuteri ATCC PTA 6475 is effective in suppressing disease symptoms caused by EHEC. When germfree Swiss Webster mice are monocolonized with EHEC, they develop disease characterized by weight loss, cecal luminal fluid accumulation, and renal tubular necrosis. When L. reuteri was administered 1 day prior to EHEC challenge and every other day thereafter, EHEC colonization was suppressed and mice were significantly protected from the manifestations of disease. Protection from disease did not require the induction of the antimicrobial compound reuterin in L. reuteri prior to treatment. The twice-daily administration of L. reuteri appeared more effective than every-other-day administration. These data indicated that L. reuteri partially protects mice from disease manifestations of EHEC.