Effect of various diets on toxin production by two strains of Clostridium difficile in gnotobiotic mice.

When axenic mice fed a commercial diet were monoassociated with two toxigenic strains of Clostridium difficile, 100% of them died 3 days after inoculation and both enterotoxin and cytotoxin were produced in their intestinal tract. However, when axenic mice were fed various semisynthetic diets before C. difficile challenge, some of them survived and their fecal cytotoxin and enterotoxin productions were highly reduced, whereas the C. difficile population level did not decrease to a great extent. Thus, gnotobiotic mice associated with C. difficile were a good model for the study of modulation by the dietary regimen of intestinal cytotoxin and enterotoxin production.