Assessing the Dose Response of a Lead Fiber Snack Prototype
Condition: Microbiota; Gastrointestinal Microbiome
Study type: Interventional

Summary: 
      Aim: To test the effects of a fiber-blend containing snack prototype in an escalating dose
      regimen (from 1 to 3 servings per day over a period of 6 weeks) on the configuration and gene
      content of the gut microbiota of overweight and obese participants (BMI 25-35 kg/m2), while
      consuming a controlled diet that contains quantities of saturated fats in the upper tertile
      and quantities of fruits and vegetables in the lower tertile of consumption in the NHANES
      database (high saturated fat-low fruit and vegetable; HiSF-LoFV). Changes in the
      representation of bacterial genes involved in carbohydrate utilization in the microbiomes of
      participants will be correlated with changes in plasma biomarkers at the end of each
      escalating dose phase by comparing features of their pre- vs post-treatment plasma proteomes
      and metabolomes.

      Design: Participants will be asked to continue to consume their habitual diet (free diet
      phase) for 1 day prior to being provided with a HiSF-LoFV diet in the form of packed-out
      meals and snacks to consume for the following 62 days. Ten days after starting to consume the
      HiSF-LoFV diet, participants will supplement this diet with a fiber-blend containing snack
      (~10g fiber/serving) once daily for a total of 14 days; the energy contribution from the
      HiSF-LoFV diet will be reduced accordingly to maintain energy needs during this time and the
      remainder of the study. For the next 14 days, the diet will be supplemented with two of the
      same fiber-blend containing snacks per day, followed by 14 days in which the snacks will be
      consumed three times daily. Subsequently, a 'wash-out' phase of ten days in which the
      HiSF-LoFV diet is consumed without any of fiber snack supplementation will conclude the
      study. Stool, urine and blood will be sampled periodically throughout.
    


Intervention name(s): Controlled, high fat/low fiber diet background diet, sequentially supplemented with an escalating dose of a fiber-blend snack food.
Intervention type(s): Other
Intervention description(s): Phase 1: Participants will be provided with a high fat/low fiber diet in the form of packed out meals and snacks for 10 days in total (days 2-11 and days 54-63)
Phase 2: Participants will be provided with the high fat/low fiber diet, plus 1 daily fiber-blend snack serving from days 12-25
Phase 3: Participants will receive 2 daily fiber-blend snack servings to supplement the high fat/low-fiber diet from days 26-39.
Phase 4: Participants will receive 3 daily fiber-blend snack servings to supplement the high fat/low-fiber diet from days 40-53.
Phase 5: Participants will return to the unsupplemented high fat/low fiber diet for days 54-63
Intervention model: Sequential Assignment
Intervention model description: Fiber supplementation increasing by 10.2g per 2-week dosing period, from 0 to 30.6g supplemental fiber at the end of the dose escalation.
Masking: None (Open Label)
Primary purpose: Other