Hi, Thanks for using the HCM. I am happy to address your questions, Florastor is a unique probiotic supplement that is used by many people. Saccharomyces Boulardii is yeast that is used in florastor. Florastor is able to maintain healthy balance micro-organisms which benefit the intestinal tract of the humans. It is also beneficial in treating diarrhea. An increase in stomach gas or bloating may occur. If any of these unlikely but serious side effects occur like signs of infection (such as high fever, chills, persistent cough). However, seek immediate medical attention if you notice any of the following symptoms of a serious allergic reaction rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing. This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor. All medicines may cause side effects, but many people have no, or minor, side effects with omeprazole magnesium. Side effects are diarrhea; gas; headache; nausea; stomach pain; vomiting or severe allergic reactions. Hope I have answered your query. If you have any further questions I will be happy to help. Thanks