Elemental diet composition and the structure and function of rat small intestine: comparison of the effects of two diets on morphology and in vivo absorption of water

Abstract

The effects of feeding elemental diets on small bowel structure and function in normal rats has been investigated, and two commercial diets Vivonex (#1) and Flexical (#2) compared. Rats were fed Diet #1 (n = 12) or Diet #2 (n = 12) for 1 month and jejunal and ileal histology compared with that of an equal number of rats fed on a normal pelleted diet. Diets #1 and #2 significantly increased villus height and decreased crypt height to villus height ratio in both jejunum and ileum (p less than 0.02 in all cases). Crypt height was also significantly reduced in the ileum but not jejunum by both elemental diets (p less than 0.05 in both cases). Segments of jejunum or ileum were perfused by an in vivo technique and water absorption measured to assess small bowel function. No significant difference in absorption was found between the rats fed Diet #1 and controls but absorption of water was depressed in both jejunum and ileum of those fed Diet #2. Small intestinal absorptive function is thus influenced by the composition of the elemental diet.