Intestinal permeability in newborns with necrotizing enterocolitis and controls: Does the sugar absorption test provide guidelines for the time to (re-)introduce enteral nutrition?

Background: In necrotizing enterocolitis (NEC), (sub)mucosal edema, hemorrhage, ulceration, or necrosis will disturb intestinal integrity, as reflected by an increased intestinal permeability. Enteral substrate is therefore withheld for a variable period up to 3 weeks tin many clinics). The authors used the sugar absorption test to measure intestinal permeability changes in surgically treated necrotizing enterocolitis patients and surgical controls to evaluate the usefulness of this test in timing the (re-)introduction of enteral feeding in NEC patients as intestinal integrity recovers. Methods: Changes in intestinal permeability to lactulose and rhamnose were evaluated prospectively in 13 children with NEC and 10 operated control patients. The patients were given 1 mL/kg body weight lactulose/rhamnose solution at different time intervals after admission. The lactulose to rhamnose (UR) ratio was determined by gaschromatography in 4-hour urine samples. Results: The UR ratios in NEC patients were increased for prolonged periods of time with a tendency to decrease in the third week after the start of NEC, However, in some cases, the increased UR ratios even exceeded the 3-week period of starvation. High peaks in the UR ratio were seen in patients suffering from bowel perforation or sepsis. Compared with necrotizing enterocolitis patients, UR ratios of control patients were increased only in the first days after surgery and normalized more rapidly. The results of the VR tests in this study corroborated the clinical condition of the patients. Conclusions: The sugar absorption test shows an individual variability in the recovery of intestinal permeability in a group of seriously ill newborns with advanced stages of NEC. An individual approach in restarting enteral nutrition seems to be justified; however, the optimal time-point to restart enteral nutrition cannot be determined by the sugar absorption test alone. Combining parameters of intestinal integrity and function could enable a more accurate determination of this optimal timepoint.