oligozaharide

Oligosaccharide, or oligozaharide in Romanian, is a carbohydrate composed of a small number of monosaccharide units, typically three to ten, linked by glycosidic bonds. They are shorter than polysaccharides and longer than disaccharides, and they display substantial structural variety in monomer composition, linkages, and branching.

Oligosaccharides can be classified by their sugar composition (homooligosaccharides built from a single monosaccharide vs. heterooligosaccharides containing two or more kinds), and by the type of glycosidic bonds (for example α- or β-linkages such as α-1,4 or β-1,6). Common examples that occur in nature include raffinose and stachyose in seeds, and fructooligosaccharides (FOS) and galactooligosaccharides (GOS) used as prebiotics. Sucrose and lactose, while well known, are disaccharides and thus lie outside the typical oligosaccharide size range.

In metabolism, many oligosaccharides are not digested by human enzymes and pass to the colon, where they are fermented by gut microbiota. This fermentation can produce short-chain fatty acids and gases and may influence gut health. Some oligosaccharides are readily hydrolyzed or absorbed in the small intestine, contributing to caloric intake in specific contexts.

Biologically, oligosaccharides often serve as components of glycoproteins and glycolipids, playing roles in cell recognition, signaling, and host–microbe interactions. They are also studied and engineered for research, therapeutics, and as ingredients in the food industry, particularly as prebiotics or functional additives.