Study of Intestinal Permeability in Patients With Anorexia Nervosa

Overview

In healthy humans, the intestinal mucosa acts as an absorption organ and a defensive barrier preventing the passage of toxic substances from the intestinal lumen to the blood stream. Malnutrition and absence of exogenous luminal nutrients in the gastrointestinal tract profoundly affect small bowel morphology and physiology. Many reports have described alterations of ion and nutrient transport, mucosal atrophy and modifications in the intestinal permeability to macromolecules in cases of prolonged intestinal rest, as in severe starvation. These changes may dampen both the absorptive and the barrier functions of intestinal mucosa. The assessment of intestinal permeability, by measuring the urinary excretion of substances that are not metabolised by human tissues and passively cross the intestinal epithelium, is a reliable and non invasive method to investigate the anatomo-functional integrity of the intestinal mucosa. Previous studies have shown an increase of permeability in malnourished humans . The increase of may also increase the risk for inappropriate passage of food antigens and other noxious substances across the mucosal barrier. To this regard, the enhanced susceptibility of malnourished subjects to systemic infections and postoperative sepsis has long been recognised. Anorexia nervosa is a psychiatric disorder characterised by abnormal eating behaviours aiming to decrease body weight. Typically, women with anorexia nervosa restrict food ingestion up to severe starvation. These behaviours usually lead to malnutrition and a more or less prolonged absence of luminal nutrients in the gastrointestinal tract. Therefore, alterations in the integrity and functioning of intestinal mucosa are likely to occur in this condition. There is no information on intestinal permeability in patients with eating disorders. We hypothesised that, as it occurs in simple starvation and malnutrition, intestinal permeability should be increased in fasted undernourished people with anorexia nervosa and decrease after re feeding. Therefore, in the present study, we explored intestinal permeability of 23 subjects with anorexia nervosa by means of the lactulose-mannitol test and urinary sucralose excretion and compare them to 46 controls. Moreover, auto-antibodies (α-MSH ) have been found in patients with anorexia nervosa. The origin of these auto-antibodies is still unknown , but some studies suggested a digestive origin. Moreover, modifications of intestinal flora have been described in patients with anorexia nervosa. Actually, a study of the intestinal barrier of patients with anorexia nervosa is necessary. In this study, a comparaison of intestinal permeability and autoantibodies (α-MSH) rate is proposed before and after re-feeding in patients with anorexia nervosa.