Effects of feeding diets containing lactose, agar, cellulose, raw potato starch or arabinose on the dry weights of cleaned gastrointestinal tract organs in the rat.

Abstract

Purified diets containing 25% lactose, agar, wood cellulose or raw potato starch, or 10% arabinose were compared with a control diet containing cornstarch as the only carbohydrate for effects upon dry weights of cleaned gastrointestinal organs in rats. Many effects of diets upon absolute organ weights and upon organ weights relative to body weight were found. When the lactose diet was fed for 1 week from weaning, the relative small intestine weight and the absolute and relative weights of both the cecum and the colon plus rectum were increased over the controls. When all of the diets were fed for 4–5 weeks, organ weights were increased by diets as follows: relative stomach weight by agar and cellulose, absolute and relative small intestine weights by lactose, relative small intestine weight by arabinose, absolute and relative cecum weights by all experimental diets except cellulose, and absolute and relative colon plus rectum weights by all five experimental diets. Thus, stomach growth is affected by diet little or not at all, while intestine growth is differently affected in its different regions by various diets. Increases in dry weights or numbers of fecal pellets were not at all related to increases in small intestine or cecum weight, and were not well related to increases in colon plus rectum weight. Using these facts and knowledge of certain properties of the various substances, certain ideas as to modes of action of diets in producing the observed changes were excluded.