An elemental diet controls inflammation in indomethacin-induced small bowel disease in rats: the role of low dietary fat and the elimination of dietary proteins.

Elemental diets (EDs) are effective in treating Crohn's disease. We hypothesize that low dietary fat and amino acids used as the sole nitrogen source are the major contributors for the success of EDs. We examined the influences of the addition of dietary fat and protein to an ED using an indomethacin-induced inflammation model in rat small intestine. In the ED-fed rats, the intestinal damage score was decreased compared with that in the standard chow group with decreasing intestinal permeability. By supplementing an ED with soybean oil (SO), intestinal permeability was increased to a level similar to that of the standard chow group. For this group, the intestinal damage score also increased compared with that of the ED group but did not reach the levels observed in the standard chow group. The addition of dietary proteins (using heat-denatured pancreatin) resulted in intestinal damage scores that were significantly higher than those of the ED+SO-fed group. The dietary protein increased the intestinal damage score. These results suggest that EDs control inflammation by decreasing intestinal permeability and the elimination of dietary proteins.