Abstract
The ileostomy flora was found to consist of 4×109 bacteria/g dry effluent (mean) and was composed of about equal numbers of aerobes (mainly Escherichia coli and Streptococcus faecalis), microaerophiles (S. intermedius) and a large variety of species of obligate anaerobes. The high blood-group antigenicity of intestinal glycoproteins and the low values or absence of glycosidase activity in ileostomy effluent, indicates that the ileostomy flora does not degrade mucous glycoproteins in vivo. However, during prolonged in vitro incubation of ileostomy effluents, N-acetyl-α-D-galactosaminidase and α-L-fucosidase, blood-group A and H degrading enzymes respectively, were induced and caused a substantial loss of intestinal glycoprotein blood group antigens. No inactivation of digestive proteases or leucine aminopeptidase by the ileostomy flora was observed during in vitro incubation; faeces from healthy subjects, however, did inactivate these enzymes effectively. We conclude that ileostomy effluent harbours bacterial species with the potential to produce glycosidases, but that inactivation of digestive proteases is limited to faecal species which are obviously not present in the ileostomy flora. The significance of these phenomena for the host are discussed.