Oligosaccharids

Oligosaccharids, or oligosaccharides, are carbohydrates composed of a small number of monosaccharide units, typically 3 to 10, linked by glycosidic bonds. They occur in a wide range of plants and foods and can be linear or branched. Common examples include fructooligosaccharides (FOS) and galactooligosaccharides (GOS); plant storage oligosaccharides in the raffinose family include raffinose, stachyose, and verbascose, which consist of galactose units attached to a sucrose core.

In humans, many oligosaccharids are not fully digestible because the relevant glycosidases are absent in the small intestine. They pass to the colon where gut bacteria ferment them, producing short-chain fatty acids and gas. This prebiotic effect can promote beneficial bacteria such as Bifidobacteria, though excess intake may cause bloating or flatulence in some people.

Dietary oligosaccharids contribute to fiber-like effects and may influence mineral absorption and immune function through microbiota interactions. They are widely used in foods and supplements as prebiotics and, in some cases, as texture-modifying ingredients or low-calorie sweeteners.

Analytical identification relies on chromatography and spectrometry, given the structural diversity and isomerism of oligosaccharids. The term oligosaccharids is used mainly in some European languages as a synonym of oligosaccharides.