probiotic

Definition of probiotic
National Cancer Institute

probiotic

(PROH-by-AH-tik)
A live microorganism used as a dietary supplement to help with digestion and normal bowel function. It may also help keep the gastrointestinal (GI) tract healthy. A bacterium found in yogurt called Lactobacillus acidophilus, is the most common probiotic.

Source: NCI Dictionary of Cancer Terms