Fiber Mix and Glycemic Response
Condition: Type2 Diabetes Mellitus
MeSH terms: Diabetes Mellitus, Type 2
Study type: Interventional

Summary: 
      This study determines the acute effect of a dietary fiber mix on blood glucose levels.
      Participants will consume the fiber mix as a drink and we will monitor changes in blood
      glucose levels. All participants will consume white bread as the control food.
    

Detailed description: 
      There is some evidence for increased dietary fiber intake to positively impact on metabolic
      outcomes in patients with type 2 diabetes, potentially via modulating gut microbial
      composition and functions. We have developed a dietary fiber mix that is consisted of fiber
      of various physicochemical properties to maximize the fermentability of the supplement and
      thus its effects on the gut microbiota. Since the fiber mix also contains nutrients that will
      raise blood glucose levels, we need to characterize the glycemic response to the fiber mix
      itself, before we can use it in an upcoming trial to determine the effect of dietary fiber
      supplementation on the gut microbiota and glycemic control.

      Enrolled participants will be assigned to a subject group based on their diagnosis of type 2
      diabetes and fasting blood glucose concentrations. Participants who are clinically diagnosed
      with impaired glucose tolerance or type 2 diabetes will be assigned to the
      Prediabetes/Diabetes group. For the other participants, those with fasting blood glucose <
      100 mg/dL will be assigned to the Non-Diabetes group, and those with fasting blood glucose >
      100 mg/dL will be assigned to the Prediabetes/Diabetes group.

      Participants will attend 8 food testing visits over 2 weeks. For each visit, participants
      will attend the research facility in the morning after an overnight fast. They will consume
      either white bread (with 50 g of available carbohydrates as a control food) or 60 g of the
      fiber mix (as a drink).

      Postprandial glycemic response will be assessed by changes in blood glucose levels, to be
      monitored using a continuous glucose monitoring system (FreeStyle Pro). A sensor will be
      placed on the participant's arm and will stay on until the end of the study.

      Participants will provide photos of all the food and drink and a brief description of what
      they have consumed throughout the 2-week study.
    

Intervention name(s): Fiber mix
Intervention type(s): Dietary Supplement
Intervention description(s): Participants will test white bread or fiber mix over a span of 2 weeks. During each testing block, each food will be tested twice over two consecutive days. There are 4 testing blocks in total (one for white bread and three for fiber mix).
Allocation: Non-Randomized
Intervention model: Parallel Assignment
Intervention model description: Participants will be assigned to either the Non-Diabetes or Prediabetes/Diabetes group based on their diagnosis of type 2 diabetes (if any) and their fasting blood glucose concentrations.
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: Type 2 Diabetes; Dietary fiber; Glycemic response