Saccharomyces bouldardii is a known probiotic yeast that has been commercialized to treat gastrointestinal tract diseases. The underlying mechanisms through which this yeast provides its benefits have yet to be understood. The bacteria Escherichia coli is the most prominent facultative anaerobe in the gastrointestinal tract and its presence indicates the healthiness of the tract. This led to investigating whether S. bouldarii provides its benefits by enhancing E. coli numbers. To test this, mice were given a probiotic supplement daily for one month. Fecal samples were collected and analyzed for the abundance of E. coli. To this end, samples were quantified, and colonies were tested for oxidase and indole to determine identity as E. coli. Those colonies that were oxidase negative and indole positive were determined probable E. coli. To test for any significant difference in the number of probable E. coli between the control and experimental groups, a Welch two sample t-test was used. The experimental findings did not support any significant difference in the number of E. coli in the experimental group versus the control group.