Microbiota - Prebiotics

What are the prebiotics, you would ask? They are fibres stimulating the microbial growth in the gut, when eaten, improving the gut health. These fibres can escape digestion in the small intestine, but once they reach the colon , they will be partially or completely fermented by the gut microbiota. The composition and the activity of the gut microbiota changes, because the microbes able to degrade those kind of fibres are favoured in their growth, and this is beneficial for the host (us).

Prebiotics fibres are made of oligosaccharides, chains of sugar molecules. The most known prebiotics are galactooligosaccharide (GOS), made of chains of galactose sugars and fructo-oligosaccharide (FOS) or inulin, made of fructose sugars. FOS and inulin can be found naturally in plants (onion, garlic, wheat, banana, chicory and various cereals). GOS are made by workers in dairy factories, converting lactose using beta-galactosidase enzymes. As they are digested by our microbiota, short chain fatty acids will be produced, and they will be used as an energy source, to reduce pain or influence the metabolism. 

Prebiotics like GOS, FOS and inulin are very good to stimulate the growth of Bifidobacterium and Lactobacillus microbe species/ Both of them are commonly found in breast fed babies, and sometimes are added to the formula and infant milk to mimic the effect of breastmilk and increase Bifidobacterium and Lactobacillus in infant's microbiota. They are also added to breakfast cereals, bars of cereals, cheese and custard. Apart from the microbiota fermentation product altering the host response, prebiotics can stimulate bowel movements and help with constipation, as they increase the stool weight, due to the prebiotic and the water attracted by the prebiotic.

Lactobacillus reuteri

Conclusion: Prebiotics are fibres that arrive in the colon intact. Here they are degraded, leading to the growth stimulation of the beneficial microbes in the gut. The microbial activity combined with the higher water content of the faeces will result in improved gastric health. 

Next post will be about probiotics. 

See you soon,

G.