Alterations of nutritional status in the main gastrointestinal pathologies

An impairment of nutritional status up to real malnutrition can frequently be associated to gastrointestinal diseases. The diseases of the gastrointestinal tract can be divided into five groups: those hampering the nutrient physiological transit (especially neoplastic diseases); those affecting the intestinal mucosa (such as chronic inflammatory bowel disease); those determining intraluminal maldigestion; the hepato-biliary diseases and finally, the diseases of the pancreas. In order to correctly evaluate the nutritional status of an individual, besides the determination of the common biochemical parameters, body composition by direct and indirect techniques and energy metabolism by indirect calorimetry should be measured. Patients affected by Crohn's disease showed a lower fat mass content along with higher lipid oxidation compared to patients affected by ulcerative colitis. Patients with coeliac disease at diagnosis had a reduction in both fat and fat-free mass content along with an increased utilisation of carbohydrates as fuel substrate. There are many factors potentially leading to severe malnutrition in pancreatic diseases, especially in the acute form. Due to the primary role played by the liver in the metabolism of energy substrates, an impaired nutritional status might be commonly found in cirrhotic patients. In this connection, our group reported an increased energy expenditure and lipid oxidation, and an insulin-resistant state in compensated liver cirrhotic patients. These alterations seemed to precede and probably to lead to liver-disease-related malnutrition.