Probiotics contain different types of micro-organisms such as yeast (saccharomyces boulardii) and bacteria (such as lactobacillus, bifidobacterium). Micro-organisms (flora) are naturally found in the stomach/intestines/vagina. Some conditions (such as antibiotic use, travel) can change the normal balance of bacteria/yeast. Probiotics are used to improve digestion and restore normal flora. Probiotics have been used to treat bowel problems (such as diarrhea, irritable bowel), eczema, vaginal yeast infections, lactose intolerance, and urinary tract infections.