Methods for the quantitative study of the aerobic and anaerobic intestinal bacterial flora of man.

The methods employed for the quantitative isolation of stool bacteria in man have not been standardized. Schaedler, Dubos, and Costello have outlined in detail their methods for isolation of aerobic and anaerobic bacteria in specimens obtained from mice.' However, in vitro growth factors for the isolation of the bacterial flora of mice are not applicable at all times to man. While undertaking a study of variations of intestinal bacteria in human disease states, it became apparent that considerable effort was required to establish and standardize reproducible bacteriologic techniques. The present report is a detailed account of the methods we found most satisfactory along with data obtained in normal subjects.