Utilization of 14C-labelled Escherichia coli by rats

1. Escherichia coli was grown on 14C-labelled glucose and fractions representing "whole cells", "cell contents" and "cell walls" were administered orally to rats. 2. 14C appearing as 14CO2 in the expired air and as unidentified radioactive products in urine and faeces was measured until the cumulative recovery showed little change with time. 3. All fractions were digested. The digestibility of cell walls was less than that of the other fractions. 4. There was considerable variation among individual rats.