Abstract
The isolation of a bacterial flora specifically associated with the colonic mucosa of patients undergoing large-bowel surgery is described. This flora differed from that of faeces in both the numbers and the types of bacteria isolated. The most striking difference was the reduction in the number of anaerobic bacteria isolated from the colonic mucosa. The ratio of anaerobic to aerobic was approximately 1:1 for mucosa compared with 100:1 for faeces.