The role of small intestinal bacterial overgrowth in postgastrectomy patients

Background Small intestinal bacterial overgrowth (SIBO) is expected in postgastrectomy patients; however, its role has not been clarified. This study was to estimate the prevalence of SIBO and investigate the clinical role of SIBO in postgastrectomy patients. Methods This prospective study involved 76 patients who underwent gastrectomy for early gastric cancer with no evidence of recurrence. An H-2-CH4 breath test with oral glucose challenge test was performed to diagnose SIBO and dumping syndrome. Sigstad dumping questionnaires, serum glucose, hematocrit and pulse rate were simultaneously monitored for every 30 min for 3 hours. Key Results There were significant differences in SIBO between the postgastrectomy patients and controls (77.6%vs 6.7%, P < 0.01). Abdominal fullness or borborygmus during oral glucose load were more common in SIBO-positive than in negative patients (50.8%vs 17.6%, P = 0.03), and were the independent factors for predicting SIBO in postgastrectomy patients (P = 0.02). The prevalences of dumping syndrome and hypoglycemia after oral glucose were 35 (46.1%) and 19 (25.0%), and were not different between both groups. However, the plasma glucose was significantly lower in SIBO-positive than in SIBO-negative patients at 120 and 150 min after oral glucose load (P < 0.05). No significant differences were observed in pulse rate and hematocrit in both groups. Conclusions & Inferences SIBO is common among postgastrectomy patients. It appears to be associated with postprandial intestinal symptoms and might aggravate late hypoglycemia. SIBO could be a new therapeutic target for managing intestinal symptoms in postgastrectomy patients.