Title: Health-protective mechanism of polyphyenols
Describe: The study involves the assessment of glucose management of polyphenols in vitro and in vivo system.
Consumption of polyphenols or polyphenol-rich food has been associated with decreased incidence of type 2 diabets mellitus (T2DM) and cardiovascular disease. Studies suggest that such association may be in part explained by the potentiality for certain polyphenols to influence sugar digestion and absorption in the small intestine. Carbohydrate digestion can be attenuated by inhibition of digestive enzymes such as amylase, sucrase, maltase and of monosaccharide transporters. Acarbose is one of the widely-used anti-hyperglycemic drugs that could cause a reduction in diabetes risk. Polyphenols have the potential to act in the same way as acarbose .
Some polyphenol inhibitors for a-glucodase, sucrase and maltase has been confirmed in in vitro studies where the enzyme inhibition was tested based on purified enzymes, isolated substrate and phenolic standards or plant extract. However, what people eat is not phenolic standards, not single substrate, but mixture of real food. What is the extent of enzyme inhibition activities when the inhibitors are in presence of complex substrates, as it is in real food? How enzyme inhibitors work in our gastrointestinal tract?
Some polyphenols are bond with dietary fibre which is a functional compound in our diet and will not be digested by the enzymes in our small intestine and finally arrive in colon. Dietary fiber is broken down by carbohydrate-active enzymes in the human gut microbiota into fermentable monosaccharides. The major end products of fermentation are the short-chain fatty acids butyrate, acetate and propionate, which provide approximately 10% of the involved in numerous physiological processes. When the polyphenols arrive in colon with dietary fibre, do they have any effect on carbohydrate-active enzymes of microbiota?
Thus the main objectives of this project is to test the effect of polyphenols on digestive enzyme activities and carbohydrate-active enzymes in the microbiota, thus managing blood glucose and producing physiological meaning.