Grant: Operating Grant: Sugar and Health

Health authorities recommend a reduction in added sugars from sugar-sweetened beverages (SSBs) due to risk of obesity and diabetes. As a sugar-reduction strategy, finding the ideal SSB replacement is of utmost importance. Those who are already consuming SSBs might not easily replace it with water and therefore non-nutritive sweetened beverages (NSBs) present a sweetened alternative though guidelines recommend water instead of NSBs as a replacement for SSBs. Recent evidence suggests that saccharine , a non-nutritive sweetener, which is not found in NSBs, might induce glucose intolerance by altering gut microbiota in humans. It is currently not known if replacing SSBs with NSBs (which contain low-calorie sweeteners other than saccharine) or water will have any effect on the human gut microbiota and any downstream diabetic risk. We plan to undertake a randomized controlled cross-over trial in 30 healthy adults to assess the effect of replacing SSBs with equal amounts of NSBs or water for 4-weeks on the composition and diversity of human gut microbiota, changes in glucose tolerance and total body fat in those who regularly drink SSBs. Each participant will act as their own control receiving each of the three interventions of SSB, NSB and water for 4 weeks in random order, each period separated by a 4 weeks wash-out period. All study visits will occur at the Clinical Nutrition and Risk Factor Modification Centre at St. Michael's Hospital. This study will contribute to knowledge that will inform dietary guidelines and public policy with regards to the best possible replacement for SSBs. It will also shed light on the potential mechanism of the adverse effects of NSBs and if the replacement of SSBs by NSBs or water are in fact similar with respect to their effect on gut bacteria and any downstream diabetic risk.