Location: Food Components and Health Laboratory
Project Number: 8040-51000-056-17-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: May 15, 2016
End Date: May 14, 2021
To investigate the effect of dietary changes in humans on their microbiota, with focus on colonic changes.
The approach for this project will be to feed human volunteers controlled diets and use microbial analysis of fecal samples as a surrogate marker for colonic microbiota composition. Human volunteers will be fed a variety of diets that may include, among other dietary manipulations, diets that are specifically designed to ask questions about the effect of vegetables, tree nuts, grains, and polyphenols on microbial composition. Fecal samples will be collected and the DNA will be extracted. The V4 region of the 16S rRNA gene will be amplified and bacterial, fungal, and archaeal library construction will be done. Amplicons will be combined in equimolar ratios to create a DNA pool that is used for sequencing. Bioinformatics will be performed to determine how consumption of specific dietary components changes in microbiota composition. This research relates to objective #1 (Delineate bioavailability, pathways of metabolism, and rates of elimination of bioactive substances from common foods (e.g., polyphenols, sulfur compounds, and other compounds as appropriate), and identify characteristics of humans that influence the body’s utilization of those bioactive substances.) and objective #2 (Determine the impact of bioactive substances from common foods (e.g., polyphenols, sulfur compounds, and other compounds as appropriate) on markers of cancer risk in human and cell models). The volunteer recruitment, feeding, and sample collection will take place at the Beltsville Human Nutrition Research Center. Approximately 300 samples will be collected from these studies. Methods of analysis will include state-of-the-science sequencing techniques coupled with appropriate computational biology.