Small intestinal bacterial overgrowth in patients with cirrhosis: Prevalence and relation with spontaneous bacterial peritonitis

OBJECTIVES: The significance of small intestinal bacterial overgrowth in pa tients with cirrhosis is not fully understood and its diagnostic criteria a re not uniform. We examined the association of small intestinal bacterial o vergrowth with spontaneous bacterial peritonitis and compared various micro biological criteria. METHODS: Jejunal secretions from 70 patients with cirrhosis were cultivated quantitatively and classified according to various definitions. Clinical c haracteristics of patients were evaluated and the incidence of spontaneous bacterial peritonitis was monitored during a 1-yr follow-up. RESULTS: Small intestinal bacterial overgrowth, defined as greater than or equal to 10(5) total colony-forming units/ml jejunal secretions, was presen t in 61% of patients. Small intestinal bacterial overgrowth was associated with acid-suppressive therapy (p = 0.01) and hypochlorhydria (p < 0.001). T wenty-nine patients with persistent ascites were observed. Six episodes of spontaneous bacterial peritonitis occurred after an average 12.8 wk. Occurr ence of spontaneous bacterial peritonitis correlated with ascitic fluid pro tein concentration (p = 0.01) and serum bilirubin (p = 0.04) but not with s mall intestinal bacterial overgrowth (p = 0.39). Its association with acid- suppressive therapy was of borderline significance (hazard ratio = 7.0, p = 0.08). CONCLUSIONS: Small intestinal bacterial overgrowth in cirrhotic patients is associated with acid-suppressive therapy and hypochlorhydria, but not with spontaneous bacterial peritonitis. The potential role of acid-suppressive therapy in the pathogenesis of spontaneous bacterial peritonitis merits fur ther studies. (Am J Gastroenterol 2001;96:2962-2967. (C) 2001 by Am. Coll. of Gastroenterology).