AIM: Nutritional depletion has been correlated with low plasma and mucosal glutamine concentrations and with increased intestinal permeability. Since nutritional depletion often is associated with (chronic) inflammatory stress, this study was designed to establish the influence of depletion and inflammation on glutamine concentrations and gut barrier function. METHODS: Anthropometric parameters were calculated from 26 patients who required artificial nutrition. Glutamine concentrations in plasma and gut mucosa, gut permeability and mucosal morphology were assessed. For determination of the degree of inflammation erythrocyte sedimentation rates and (pre)albumin concentrations were measured. On the basis of these parameters patients were divided into two groups having significant inflammatory stress or not. Similarly, a depleted and a non-depleted group was formed based on percentage ideal body weight, fat-free mass index (FFMI) and percentage weight loss. Glutamine concentrations, gut permeability and villus morphology were compared between the groups. RESULTS: The presence of inflammatory activity had significant negative effects on glutamine concentrations in contrast to the presence or absence of nutritional depletion. Similarly, intestinal permeability increased during active inflammation but not in depleted patients. FFMI but not inflammation was related to villus height. CONCLUSIONS: The presence of inflammation significantly affects glutamine concentrations and gut permeability, in contrast to the presence of depletion of body cell mass per se. On the other hand, villus morphology is not influenced by changes in systemic inflammatory activity whereas nutritional status possibly does affect villus height.