Pure Encapsulations Saccharomyces Boulardii CapsulesPure Encapsulations Saccharomyces Boulardii Pure Encapsulations Saccharomyces Boulardii is a yeast based probiotic supplement that contains 5 billion live cultures. These microorganisms promote the balanced development of your intestinal flora and can help maintain intestinal health and overall well being.* Did you know that most of your immune system can be found in your gut? A healthy microbiome plays a major role in healthy immune function.*