Feline colonic morphology and mucosal tissue energetics as influenced via the source of dietary fiber

Twenty-eight adult female cats were used to assess the effects of dietary fiber on feline colonic morphology, mucosal cell density and tissue energetics. Three sources of dietary fiber (i.e., cellulose, beet pulp and a pectin/gum arabic blend) and a non-fiber control diet were compared. The fiber sources were selected according to their degree of fermentation and degradation within the colon of the domestic cat and dog. The feeding of the non-fermentable, cellulose diet, resulted in greater colonic weight and colonic weight per kg body weight when compared to those cats receiving the non-fiber, control diet. Colonic mucosal surface area to colonic mass ratio was significantly increased for all fiber diets (cellulose > beet pulp > pectin/gum arabic) when compared to the non-fiber diet. The colonic crypt depth and crypt width values were not altered by the addition of fiber to the diet. However, the addition of fiber to the diet significantly increased colonic mucosal energetics (per gram of tissue), and the individual mucosal cell energetics (per unit DNA), when compared to the non-fiber fed cats. Contrary to the noted increase in colonic surface area associated with the decrease in fermentability of the fiber source, the addition of the more fermentable fibers enhanced the colonic mucosal cell energetics (i.e., pectin/gum arabic > beet pulp > cellulose > non-fiber diet). While dietary fiber is not a natural component of domestic cat diets, the increase in colonic weight and in mucosal cell activity resulting from the addition of fiber are suggestive of enhanced colonic health. (C) 2000 Elsevier Science Inc.