Assessing the glycemic lowering potential of kombucha when consumed with a high glycemic index meal by healthy volunteers with normoglycemia.

The glycemic index (GI) is a metric that ranks the glycemic potential of carbohydrate foods using a scale from 0 to 100 where glucose = 100. The GI of a given food is the relative extent to which the 50 g of available carbohydrates in a food or drink (gram for gram) raise blood glucose levels compared to an equivalent amount of pure glucose. Our studies are conducted according to the International standard for the determination of the glycemic index of foods (ISO 26642:2010). In this instance, GI methodology will be used to assess the glycemic lowering potential of a popular fermented drink known as kombucha. A meal with and without various beverages will be fed to a group of healthy volunteers who have fasted overnight (10-12 hours fasting, water only). The meal and drink must be consumed under within 15 minutes from the first mouthful. The food will be prepared and administered by university research assistant, who will also teach the participants how to collect their own blood by finger-pricking. Fingerprick blood samples will be collected by the individual at regular intervals over 2 hours while sitting quietly in the research facility. The research assistant will prepare the blood for measuring blood glucose in the glucose autoanalyser (Beckman Coulter AU-480).The concentration of glucose in the blood will be measured and incremental area under the curve (iAUC) calculated. On another day, the same people return to our lab, and the procedures are repeated after they have consumed an equal-carbohydrate portion of the reference food (glucose sugar in water). The iAUC value for the test food/meal is expressed as a percentage of the average response produced by the reference food. There is a 24 hour wash-out period between tests. The meals and drinks to be tested are: 1. Reference food of 50 g glucose solution. 2. Jasmine rice, peas and soy sauce with 330mls kombucha 3. Reference food of 50 g glucose solution. 4. Jasmine rice, peas and soy sauce with 330mls soda water 5. Reference food of 50 g glucose solution. 6. Jasmine rice, peas and soy sauce with 330mls diet lemonade.