Galacto-oligosaccharides GOS, also known as oligogalactosyllactose, oligogalactose, oligolactose or transgalactooligosaccharides TOS, belong to the group of prebiotics. GOS occurs in commercially available products such as food for both infants and adults. The composition of the galacto-oligosaccharide fraction varies in chain length and type of linkage between the monomer units. Galacto-oligosaccharides are produced through the enzymatic conversion of lactose, a component of bovine milk. A range of factors come into play when determining the yield, style, and type of GOS produced. These factors include. GOS generally comprise a chain of galactose units that arise through consecutive transgalactosylation reactions, with a terminal glucose unit.
GOS has a number of benefits for consumers of dairy products. From a labeling perspective, GOS has been recognized by the FDA as a non-digestible carbohydrate and therefore added to the definition of dietary fiber. Dietary fiber consumption brings numerous well-documented benefits, primarily by promoting the growth of beneficial bacteria in our lower gastrointestinal tract. And GOS is particularly good at enabling us to build that microbiome. Though several definitions exist, prebiotics are often described as non-digestible food ingredients that benefit those who eat them by selectively stimulating bacterial activity in the colon. Well, in humans, GOS are preferentially metabolized by Bifidobacteria, giving this type of beneficial bacteria a leg-up on its competitors. Bifidobacteria produce short chain fatty acids SFCA such as butyrate, propionate and acetate which can be metabolized by our bodies and linked to a number of benefits.
These often make up dietary fibre, and they are usually good for us, helping friendly bacteria to thrive. Here our expert Ali discusses what they are, and how they affect our digestive system. An oligosaccharide is characterised by a carbohydrate chain made up of monosaccharides simple sugars. In the foods we eat, oligosaccharides are often components of dietary fibre. Oligosaccharides are malabsorbed by the small intestine and therefore go on to undergo fermentation in your large intestine. This will naturally mean some gas and subsequent flatulence may be produced with the consumption of oligosaccharides but, if you suffer from IBS, a cascade of more intense symptoms is often the result. However, if you suffer from IBS, prebiotics are often not well tolerated and may cause more problems than benefits. There are two types of oligosaccharides; fructans and galacto-oligosaccharides GOS, which we will discuss below in more detail below.