ObjectiveTo assess gastrointestinal permeability and functional absorptive capacity in patients with sepsis.DesignCase control study to analyze gastrointestinal permeability and functional absorptive capacity of septic patients by differential saccharide absorption (from an oral test solution) and excretion.SettingThe Intensive Therapy Unit of St. Thomas' Hospital, London, UK.PatientsTwenty patients with a mean Acute Physiology and Chronic Health Evaluation (APACHE) II score of 18.4 who were admitted to the intensive care unit with a diagnosis of sepsis. All patients were on enteral feeding. Patients with abdominal pathology were excluded.InterventionsAn oral test solution containing 5 g of lactulose, 1 g of L-rhamnose, 0.5 g of D-xylose, and 0.2 g of 3-O-methyl-D-glucose dissolved in water to a final volume of 100 mL was administered to patients and controls. Urine was collected for 5 hrs starting immediately after administration of the test solution and the saccharide content of the urine was estimated and expressed as a percentage recovery of the oral test solution.Measurements and Main ResultsSeptic patients had increased lactulose/L-rhamnose urine excretion ratios (0.23 plus minus 0.19) compared with control subjects (0.03 plus minus 0.01, p less than .001), consistent with increased gastrointestinal permeability in sepsis. Septic patients had decreased L-rhamnose/3-O-methyl-D-glucose urine excretion ratios (0.14 plus minus 0.07) compared with normal controls (0.28 plus minus 0.08, p less than .001), consistent with decreased gastrointestinal functional absorptive capacity in sepsis.ConclusionsPatients with acute sepsis exhibit increased gastrointestinal permeability and decreased gastrointestinal functional absorptive capacity in comparison with healthy control subjects. These abnormalities may contribute to the pathophysiology of sepsis.(Crit Care Med 1996; 24:1144-1149)