Assessing the Dose Response of a Lead Fiber Snack Prototype

Study 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.

Primary Outcome

Changes to the gut microbiota/microbiome as a function of background diet and fiber dose escalation using culture independent methods. Investigators will use higher order singular value decomposition (HOSVD) to analyze changes in the gut microbiome - including the representation of carbohydrate-active enzyme genes (CAZymes), metabolic pathways and Amplicon Sequence Variants (ASVs) in shotgun sequencing datasets generated from fecal DNA collected at the beginning and end of each dose escalation p

Conditions Studied

Interventions

• OTHER Controlled, high fat/low fiber diet background diet, sequentially supplemented with an escalating dose of a fiber-blend snack food.

Study Locations (1)