Intestinal Microflora in Patients with Alcoholic Cirrhosis: Urea-Splitting Bacteria and Neomycin Resistance

The microflora of the small and large bowel was studied in 24 patients with biopsy-proved alcoholic cirrhosis. Urea-splitting bacteria were found in 21 patients (88%); these strains were Klebsiella in 19 cases and Proteus in 2. Abnormal colonization of the upper small bowel was seen in 12 patients, including 6 with urea-splitting bacteria. A "control" group of 9 hospitalized patients without liver impairment also had a high incidence of colonization of the bowel by urea-splitting Klebsiella (5 cases, 56%); 4 of these 9 patients had upper small bowel contamination with Klebsiella. Neomycin-resistant Klebsiella were present in 3 patients with cirrhosis (14%). An additional patient studied while receiving neomycin had luxuriant growth of resistant Klebsiella in the ileum and stool. These studies indicate that the gastrointestinal tract of patients with cirrhosis is frequently colonized by urea-splitting bacteria which in some individuals may be resistant to neomycin. While these findings are not specific for cirrhosis, they have enhanced significance in patients with liver failure.