A live form of a bacterium that makes lactic acid (a substance that is made from sugars found in milk and is also made in the body). Culturelle is given to help with digestion and normal bowel function. It may also help keep the gastrointestinal (GI) tract healthy. It is being studied in the prevention of infections in patients having donor stem cell transplants and in other conditions. Also called Lactobacillus rhamnosus GG.