Effect of four enteral foods on the small bowel of undernourished rats after midgut resection.

OBJECTIVE: To describe the effects of new enteral foods on the adaptation of the gut mucosa after massive intestinal resection in rats. DESIGN: Laboratory experiment. SETTING: Teaching hospital, Spain. SUBJECTS: 91 male Wistar rats, 69 of which were studied (5 were excluded and 17 died). INTERVENTIONS: Previously undernourished rats were subjected to either massive bowel resection (n = 30) or laparotomy (n = 26) and fed four enteral hypocaloric diets for 7 days: Alitraq (n = 7 in each group), Impact (n = 8 and 7), Enrich (n = 8 and 6), and Elemental (n = 7 and 6). The remainder were not operated on and fed chow (n = 7) or a diet containing no protein (n = 6). Two diets were high in protein (Alitraq and Impact) and two contained normal amounts (Enrich and Elemental). MAIN OUTCOME MEASURES: Bowel mucosal thickness and proliferation; disaccharidase activity; intestinal weight and length; body weight; and plasma somatostatin, IGF-1, and peptide YY concentrations. RESULTS: Enriched diets provided a higher body and intestinal weight, and increased length of jejunal and ileal villous size. Peptide concentrations were modified by resection but not by the diet given. Concentrations of somatostatin and insulin-like growth factor were reduced in all groups with the exception of somatostatin in the two diets high in protein in the sham-operated rats. CONCLUSIONS: Enriched diets all improve the intestinal adaptive response to massive bowel resection in rats, offering advantages over diets with normal amounts of protein.

[Response of the intestinal mucosa to different enteral diets in situations of surgical stress and malnutrition]. / Respuesta de la mucosa intestinal a diferentes dietas enterales en situaciones de estrés quirúrgico y desnutrición.

INTRODUCTION AND OBJECTIVES: malnutrition and surgical stress is a relatively common association. At present, different enteral nutrition formulation are available, which are potentially applicable to different pathological conditions. The use of one diet or another may modify both the nutritional state as the intestinal structure and function. The objective of this study is to evaluate, in a malnutrition and surgical stress model in the rat, the effect of four enteral diets on the ponderal and structural evolution of the intestinal mucosa. MATERIAL AND METHODS: adult Wistar rats weighing 230 g divided into four groups (n = 8/group), according to the enteral nutrition diet administered (elemental-elemental-028, polymeric with fiber-Enrich, peptidic with glutamine-Alltraq, and rich in arginine, fatty acids, and CO3 impact). All animals were subjected to an acute protein deficit for one week, and surgical stress consisting of the performance of a laparotomy. During another week the animals were fed with one of the four diets on a hypocaloric base of 195 kcal/week/rat, to maximize the effects of each diet, after which the animals were sacrificed. Determinations were made of body and intestinal weight variations, and samples were taken of the jejunum, ileum, and colon tissue. A histomorphometric study was conducted on these samples (crypt length and villosity). RESULTS: all groups lost weight in a similar manner with respect to the initial weight, with the exception of the animals fed with the polymeric diet with fiber, whose weight loss was even more marked. The intestinal weight was greater in those animals who received an arginine rich diet. In the jejunum and ileum samples the villus length was greatest in the group receiving a glutamine rich diet, with the length being shortest when fed with the elemental diet. The crypt depth showed as similar variation. In the colon, the greatest crypt depth was seen in the animals who received a fiber rich diet. DISCUSSION AND CONCLUSIONS: diets rich in glutamine and arginine, as well as the elemental diet, are more efficient when it comes to maintaining body weight, although the latter is the one which maintains the small intestine weight the least, without there being a direct relation between these two parameters. The enriched diets are the ones which give the best results when it comes to maintaining body weight and mucosal mass. In the colon, the fiber enriched diet stimulate the growth of colonic mucosa.