BACTERIOLOGICAL ANALYSIS OF MUCOSAL BIOPSY SPECIMENS FOR DETECTING SMALL-INTESTINAL BACTERIAL OVERGROWTH

Background: Although culture of luminal secretions is regarded as the most accurate diagnostic test for small-intestinal bacterial overgrowt h, obtaining an aspirate is often difficult owing to the sparseness of luminal secretions present at the time of aspiration. Obtaining a muc osal biopsy specimen for bacteriologic analysis would overcome this pr oblem. Methods: Culture of small-intestinal and gastric aspirates and unwashed small-intestinal mucosal specimens was performed in 51 adult subjects investigated for small-intestinal overgrowth. Results: Highly significant (r = 0.85 - 0.90; p < 0.0005) cor relations were found be tween viable bacterial counts in small-intestinal luminal secretions a nd biopsy specimens. Small-intestinal bacterial overgrowth was present in 60.8% of subjects. When specimens weighing 4.0-84.0 mg were suspen ded in diluent, total aerobic and/or anaerobic bacterial counts greate r than or equal to 10(2) CPU/ml were found to have 90.3% sensitivity a nd 100% specificity for small-intestinal bacterial overgrowth. Conclus ion: Culture of an unwashed small-intestinal mucosal biopsy specimen i s a useful alternative to culture of a small-intestinal aspirate for d etecting subjects with small-intestinal bacterial overgrowth, especial ly when luminal secretions are scanty at the time of aspiration.