Dietary influence on colonic cell renewal

Abstract

Previous studies have indicated that marked alterations in the proliferative activity of the murine intestinal epithelium can be induced through noninjurious fasting and refeeding. The response to refeeding is especially pronounced in the colon, where proliferative activity exceeds twice the control levels within 12 to 16 nr. In the present study, the role of specific dietary components in the control of the colonic refeeding response and in normal colonic cell renewal have been investigated. The results indicate the colonic refeeding response to be dependent upon the presence of sugar, amino acids and minerals, in the form of salts, in the refed diet. In the nonfasting animal, normal colonic cell renewal also requires dietary minerals. The absence of minerals in a maintenance diet results in a marked hypoproliferative state that can be reversed by reintroducing the mineral component of the diet. That the depressed proliferative rate observed with a salt-free diet is not the result of a caloric depletion is evidenced by the maintenance of body weight throughout the experimental period. These findings suggest a potential role for specific dietary components in the control of the colonic cell proliferation, maintenance of the steady state cell renewal system, and represent a tool by which the proliferative activity of the gut may be manipulated.