BLEND

It is now widely recognised that much of the metabolism of the major polyphenol classes occurs in the large intestine, under the control of the resident microbiota. The microbiota degrades parent polyphenolics to a range of intermediates and end-products such as phenolic acids. Evidence is emerging for the health benefits of these intermediates and end-products and given their high bioavailability in comparison to the parent compounds, they may explain in a large part many of the biological effects of polyphenolics.

The main substrates driving metabolic activity of the microbiota in the large intestine are fermentable carbohydrates derived largely from dietary fibre. Our preliminary evidence suggests that there is an interaction between carbohydrate fermentation and polyphenol metabolism in the large intestine. However, a greater understanding of this interaction is necessary in order to predict and manipulate the way polyphenols are metabolised by the gut microbiota.

Manipulating the microbiota with fermentable carbohydrates will mimic the whole-food scenario under normal dietary conditions when polyphenols are released from foods alongside fermentable carbohydrate. The fermentable carbohydrate component will influence the activity of the microbiota and therefore the bioavailability of polyphenolic intermediates and end-products. In addition, the polyphenols may also act with prebiotic and antimicrobial properties, which together with fermentable carbohydrate may promote a more health associated microbiome.

This project will provide new insights into the relationship between fermentable carbohydrates and polyphenols and the role the gut microbiota plays in mediating the health benefits of polyphenol rich foods. Importantly it will also inform Industry about compositions which maximise the bioavailability of phenolic acids and the role these play in mediating the protective effects of polyphenols in health. With increasing pressure, particularly in the beverage market, to reduce sugar intake, replacement of sugar with alternative carbohydrates may be an important avenue to optimising polyphenol intake and polyphenol bioefficacy.