Location: Immunity and Disease Prevention Research
Project Number: 2032-10700-002-000-D
Project Type: In-House Appropriated
Start Date: Jan 18, 2024
End Date: Jan 17, 2029
Objective:
Objectives are to (1) determine the effect of dietary composition on gut microbiota composition and function, (2) determine the effect of diet and/or microbial-derived products on gastrointestinal health, and (3) determine the effect of diet and/or microbial-derived products on immune function and systemic inflammation.
Approach:
We propose human clinical trials as well as in vitro and rodent studies to determine the effect of fermentable fiber and/or fermented foods on microbial, gastrointestinal, and immune responses. To understand the effects of fermentable fiber, we will continue an ongoing fiber intervention study in humans undergoing a vaccine challenge with the Vivotif vaccine. We will also conduct a new intervention study in an animal model with antibiotic challenge in which animals are placed into four groups: low fiber, low diversity of fiber sources; low fiber, high diversity of fiber sources; high fiber, low diversity of fiber sources; high fiber, high diversity of fiber sources. To understand the effects of fermented foods, we will design and test a microbe-containing foods intake assessment questionnaire to estimate intake of fermented foods in the past one week. Meanwhile, we will conduct a pilot study of short-term intake of novel fermented vegetables to determine tolerability and lactic acid bacteria abundance in young healthy people before conducting a full trial with older participants. We will also conduct in vitro studies of fermented and unfermented vegetables as well as the components of fermented vegetables (whole food, lactate, lactic acid bacteria) to deconstruct their relative contributions to measurable outcomes in cell systems. Finally, we will conduct a full randomized controlled trial with two interventions (fermented vegetables, placebo acidified vegetables) in a cross-over study design to determine the impact of these foods on the gut microbiome, gastrointestinal health, and immune health of older adults, 50-75yr. These studies will provide much-needed scientific evidence on the intake of fiber and fermented foods for the Dietary Guidelines for Americans
