Xylooligosaccharide (XOS) is a functional, plant-derived prebiotic composed of short chains of xylose molecules. Naturally found in fruits, vegetables, and plant fibers, XOS is known for its powerful ability to selectively stimulate the growth of beneficial gut bacteria, particularly Bifidobacteria, even at low doses. It is highly stable, low in calories, and widely used in gut health supplements, functional foods, and beverages aimed at improving digestion and overall microbiome balance.