Experimentally induced ileal ulcers in rats. Formula diet is a preventive factor.

We recently described an experimental model in the rat to create recurring chronic ileal inflammation including ulceration. This model is dependent on an "in vivo culture" of normal intestinal contents. In the present experimental study we examined the effect of a polymeric and a hydrolyzed formula diet on the formation of ulcerating lesions using our rat model. Two groups of rats (twenty in each group) were fed either one of these formula diets eight weeks prior to the experimental procedure and this diet was continued until sacrifice eight weeks later. Twenty control rats also underwent the experimental procedure but were fed standard rat pellets for the same time periods. At sacrifice 60% of the control rats had developed ileal ulcers. None of the rats fed the formula diets developed macroscopic ileal inflammation or ulceration. The effectiveness of formula diets in inducing remission in Crohn's disease in humans may be linked to alterations in the intestinal microflora. We hypothesize that the formula diets in this experiment exerted a protective effect against ileal ulceration by altering the ileal microflora. Preliminary studies support this hypothesis but need to be expanded.