# Dissecting the effect of diet on gut microbiome metabolism

> **NIH NIH F30** · PRINCETON UNIVERSITY · 2024 · $32,974

## Abstract

Project Summary
 Gut microbiome products such as indole and phenol metabolites have major impacts on host physiology.
Decreased production of these important metabolites is linked with many diseases, and increasing circulating
concentrations of indole or phenol metabolites ameliorates inflammatory bowel disease or obesity in mouse
models, respectively. Diet is a promising tool for treating microbiome-related diseases, as dietary modifications
can affect both microbial composition and metabolism, but dietary control of indole and phenol production is still
underexplored. Here, this work will dissect the effect of dietary components such as protein, fiber, and processing
on microbial production of phenol and indole metabolites. The overarching hypothesis driving this work is that
diet controls microbial metabolism through altering the balance of dietary or secreted protein available to the
microbiome. Aim 1 will investigate the effect of protein digestibility and dietary processing on microbial
metabolites. Liquid chromatography-mass spectrometry (LC-MS) will be used to measure circulating and fecal
metabolites and 16S rRNA sequencing will be used to measure microbial composition in mice fed differentially
processed (e.g. cooking, grinding) diets. Additionally, the contribution of dietary protein fermentation will be
directly measured via 13C-labeled protein diets. Aim 2 will examine the effect of dietary fiber and mucin production
on microbiome metabolism. Through isotope tracing and techniques developed by the Rabinowitz lab, and we
will measure the contribution of microbial fermentation of host-secreted proteins to microbial metabolites.
Additionally, dietary fiber can impact both the production of host-derived mucin as well as the abundance of
bacteria that can ferment the mucin. In mice fed diets with different types of fiber (e.g. inulin, pectin, cellulose),
mucous layer thickness will be measured through histologic staining, microbiome composition will be assessed
by 16S rRNA sequencing of fecal samples, and metabolite concentrations in feces and serum will be analyzed
via LC-MS. Completion of the work proposed here will provide a critical foundation for the understanding of
dietary control on production of indole and phenol metabolites. By unlocking the potential for targeted dietary
control of desired metabolites, this work could eventually facilitate dietary formulations to help treat patients
suffering from microbiome-related diseases such as inflammatory bowel disease and obesity.

## Key facts

- **NIH application ID:** 10997937
- **Project number:** 1F30DK139739-01A1
- **Recipient organization:** PRINCETON UNIVERSITY
- **Principal Investigator:** Jenna Abusalim
- **Activity code:** F30 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $32,974
- **Award type:** 1
- **Project period:** 2024-12-16 → 2025-09-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10997937

## Citation

> US National Institutes of Health, RePORTER application 10997937, Dissecting the effect of diet on gut microbiome metabolism (1F30DK139739-01A1). Retrieved via MORVS 2026-10-24 from https://api.morvs.ai/grant/nih/10997937. Licensed CC0.

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