Saccharomyces boulardii is a yeast, which is a type of fungus. Saccharomyces boulardii was previously identified as a unique species of yeast, but is now believed to be a strain of Saccharomyces cerevisiae (baker's yeast). Saccharomyces boulardii is used as medicine.
Saccharomyces boulardii is used for treating and preventing diarrhea, including infectious types such as rotaviral diarrhea in children, diarrhea caused by gastrointestinal (GI) take-over (overgrowth) by bad bacteria in adults, traveler's diarrhea, and diarrhea associated with tube feedings. It is also used to prevent and treat diarrhea caused by the use of antibiotics.
Saccharomyces boulardii is also used for general digestion problems, irritable bowel syndrome (IBS), inflammatory bowel syndrome (IBD, Crohn's disease, ulcerative colitis), Lyme disease, a bowel disorder called relapsing Clostridium difficilecolitis, and bacterial overgrowth in short bowel syndrome.
Some people use Saccharomyces boulardii for lactose intolerance, urinary tract infections (UTIs), vaginal yeast infections, high cholesterol levels, hives, fever blisters, canker sores, and teen-age acne.