Diabetic intestinal growth adaptation and glucagon-like peptide 2 in the rat: effects of dietary fibre

Background/Aims-Dietary fibre influence growth and function of the upper ga strointestinal tract. This study investigates the importance of dietary fib re in intestinal growth in experimental diabetes, and correlates intestinal growth with plasma levels of the intestinotrophic factor, glucagon-like pe ptide 2 (GLP-2). Methods-Male Wistar rats were randomised to the following groups: two strep tozotocin-diabetic and two control groups fed either a fibre-containing or a fibre-free diet for three weeks. Intestinal weight, length, and morphomet ric data (villus height, villus area, crypt depth) were measured. Blood sam ples were obtained after two weeks for measurement of GLP-2 and enterogluca gon (glicentin, oxyntomodulin). Results-The mean daily consumption of food in the two diabetic groups was 4 0% higher than in controls. In diabetic rats fed fibre, the increase in int estinal weight from day 0 to 20 was sixfold greater than that of the contro ls and small intestine weight per cm length was increased by 50%. In the di abetic rats fed a fibre-free diet, intestinal growth was 30% less than in d iabetic rats fed fibre, and intestinal weight increased only threefold comp ared with controls. Morphometric data showed that the intestinal increase i n diabetic rats fed fibre was due primarily to growth of the mucosal layer. Villus height and crypt depth increased 60% and 40% respectively, but by o nly 20% in fibre-free diabetic rats. The plasma levels of GLP-2 parallelled diabetic intestinal growth, whereas plasma levels of enteroglucagon increa sed regardless of the extent of intestinal growth. Conclusions-Intestinal growth in experimental diabetes is strongly influenc ed by the presence of dietary fibre. The effect may be mediated by GLP-2.