Galacto-oligosaccharides (GOS) are a group of naturally occurring carbohydrates composed of short chains of galactose molecules. Recognized for their prebiotic properties, GOS serves as a selectively fermentable substrate for beneficial gut bacteria, particularly bifidobacteria, promoting their growth and activity in the colon. GOS is naturally present in certain foods like legumes and human breast milk. As a prebiotic, GOS contributes to the development of a healthy gut microbiota, supporting digestive health and potentially enhancing the body's natural defenses. Due to their positive impact on gut flora and the potential health benefits associated with prebiotics, GOS is often used as an ingredient in functional foods, dietary supplements, and infant formulas. It is valued for its ability to provide health-promoting effects while also serving as a mild sweetener in various applications.