Bacterial translocation occurs when viable bacteria pass through the mucosa of the gastrointestinal tract to the mesenteric lymph nodes (MLN) and other organs. The ability of a diet containing 1% culture condensate of Bifidobacterium longum (MB) to inhibit bacterial translocation from the gastrointestinal tract was tested using antibiotic-decontaminated specific-pathogen-free (SPF) mice and germ-free mice, both of which were monoassociated with Escherichia coli C25. Feeding of MB diet decreased the number of E.coli C25 translocating to MLN to about half the number of the control diet group, but did not reduce the incidence of translocation to MLN. MB diet ingestion also decreased the number of E.coli C25 translocating to MLN in the SPF mice injected with zymosan, but it could not prevent bacteria translocation in mice receiving a 30% thermal injury.