Interactions Between Fibre and Polyphenols on Colonic Phenolic Acid Production and Biomarkers of Health ( 6 Weeks)

Polyphenol rich plant foods have been associated with several health benefits but their bioavailability is generally low. The majority of plant polyphenols are poorly absorbed in the small intestine and enter the colon where the colonic microbiota metabolise them to release a range of phenolic acids, which are now thought to be the main bioactive components related to the reduction in disease risk. Very little is known about the impact of other constituents of the diet on the metabolism and bacterial catabolism of these polyphenols.

Colonic bacteria are key agents in the release of the bioactive molecules from polyphenols but also ferment non-digestible carbohydrates (NDC) such as inulin to short chain fatty acids. It is likely that there are key interactions in the colonic bacterial metabolism of NDC and phenolics. The investigators hypothesize that combination of polyphenolics (in onions, tomatoes and lovage) with inulin (NDC) will increase the urinary output of bioactive phenolic acids over a 6 week feeding trial and impact on biomarkers of cardiometabolic health.

Inclusion criteria

• Generally healthy
• BMI>=25
• Not on antibiotics within 3 months of starting of study
• No medication likely to influence gut function, colonic bacterial activity.

Exclusion criteria

• Antibiotics
• Pregnancy
• lactation