Researchers studied a traditional Korean plant called Opuntia humifusa to determine if it could act as a prebiotic—a food component that promotes the growth of beneficial gut bacteria. They found that leaf extracts, particularly when prepared with 60% ethanol, effectively stimulated the growth of Lactobacillus bacteria. The active ingredient was identified as a compound called isorhamnetin glycoside, which could make this plant a natural ingredient for functional foods designed to support digestive and overall health.