The present invention relates to a dietary supplement or pharmaceutical composition, comprising lyophylized Saccharomyces boulardii as an active ingredient and as sole probiotic, optionally in association with a pharmaceutically acceptable vehicle, wherein the composition is in a closed vial a having a first airtight compartment comprising lyophilized S. boulardii powder, and a second compartment comprising a solution, wherein the first and second compartment can be brought in airtight communication with one another to yield a suspension of S. boulardii to be administered to an individual upon opening of the vial.