DIAGNOSIS OF SMALL-INTESTINAL BACTERIAL OVERGROWTH IN CLINICAL PRAXIS- A COMPARISON OF THE CULTURE OF SMALL-BOWEL ASPIRATE, DUODENAL BIOPSIES AND GASTRIC ASPIRATE

BACKGROUND/AIMS: This study was undertaken to validate the usefulness of the culture of duodenal biopsy specimens and gastric aspirate compa red to the culture of small bowel aspirate for diagnosing small intest inal bacterial overgrowth. We also investigated the occurrence of pred isposing conditions in these patients. METHODOLOGY: Seventy five conse cutive patients, admitted because of symptoms which caused us to suspe ct small intestinal bacterial overgrowth, were studied. For all patien ts, specimens for the culture of small bowel aspirate, duodenal biopsi es and gastric aspirate were obtained during upper endoscopy. RESULTS: Eighteen patients showed growth of gram negative bacteria, 22 growth of gram positive bacteria and 35 showed no significant growth in cultu res of small bowel aspirate. Cultures of duodenal biopsies revealed gr am negative bacteria in 11 patients, gram positive bacteria in 9 and n o growth in 55. Cultures of gastric aspirate revealed gram negative ba cteria in 7 patients, gram positive bacteria in 12 and no growth in 51 . Ten of the 18 patients with gram negative overgrowth and 13 of the 2 2 patients with gram positive overgrowth had a predisposing condition. In contrast, only 4 of the 35 without overgrowth had a predisposing c ondition. CONCLUSIONS: The culture of duodenal biopsy specimens or gas tric aspirate is a less sensitive method than the culture of small bow el aspirate. Most patients with culture-proven small intestinal bacter ial overgrowth had at least one predisposing condition.