KINETICS OF SACCHAROMYCES-CEREVISIAE ELIMINATION FROM THE INTESTINES OF HUMAN VOLUNTEERS AND EFFECT OF THIS YEAST ON RESISTANCE TO MICROBIAL COLONIZATION IN GNOTOBIOTIC MICE

When healthy volunteers were given a daily dose of 3 x 10(8) life-dehydrated Saccharomyces cerevisiae cells for 5 days, the volunteers excreted 10(5) living yeast cells per g of feces at first, but the yeast cells disappeared within 5 days of the end of treatment. In gnotobiotic mice, S. cerevisiae administered alone colonized the intestinal tract but did not interfere with previous or subsequent colonization by a variety of potentially enteropathogenic microorganisms. When these microorganisms were present, the intestinal counts of S. cerevisiae were greatly reduced.