oligosaccharider

Oligosaccharides are carbohydrates composed of a small number of monosaccharide units linked together by glycosidic bonds. Typically, they consist of between 3 and 10 monosaccharide units, although this definition can sometimes be extended. They are intermediate in size between monosaccharides (single sugar units) and polysaccharides (long chains of sugar units). Common monosaccharide units found in oligosaccharides include glucose, fructose, and galactose.

These molecules play diverse roles in biological systems. In humans and animals, some oligosaccharides are not digestible by host enzymes and can reach the colon, where they act as prebiotics, selectively stimulating the growth and/or activity of beneficial bacteria. Examples include fructooligosaccharides (FOS) and galactooligosaccharides (GOS). Oligosaccharides are also important components of cell surface glycoproteins and glycolipids, contributing to cell recognition and immune responses.

In plants, oligosaccharides like raffinose and stachyose serve as storage carbohydrates and are involved in stress tolerance. The specific structure and composition of an oligosaccharide determine its physical properties and biological functions. They are often sweeter than starch but less sweet than simple sugars and can be used as functional food ingredients.