# Microbiome response to dietary carotenoids

> **NIH NIH P20** · OKLAHOMA STATE UNIVERSITY STILLWATER · 2024 · $248,496

## Abstract

ABSTRACT
Research Project Leader - Lin
Imbalanced gut microbiome (i.e., dysbiosis) and altered intestinal mucosal immunity are leading factors for
developing several chronic diseases, including obesity and type 2 diabetes mellitus (T2DM). Proper dietary
patterns can promote healthy microbial community composition, metabolism, and function, thereby preventing
and/or slowing the progression of these diseases. Dietary carotenoids are beneficial food bioactive compounds
for human health. For example, zeaxanthins are essential pigments for macula in the human eye. Low plasma
levels of carotenoids, such as zeaxanthins, are associated with the progression of obesity and T2DM in
humans. Therefore, there is an urgent need to determine the roles zeaxanthin plays in the development of
obesity and T2DM. The Research Project Leader’s preliminary findings in animal models indicate that dietary
zeaxanthins reduce pro-inflammatory cytokines (such as IL-17A), increase colonic goblet cell numbers, and
alter the cecal microbiota composition. Germ-free C57BL/6J (GF) recipient mice gained significantly less
weight and had a decreased elevation of blood glucose levels when colonized with fecal microbiota from
diabetic db/db mice fed a zeaxanthin diet, compared to GF mice receiving fecal microbiota from db/db mice fed
a chow diet. Despite the recent progress outlined above, a substantial knowledge gap regarding the interplay
of dietary zeaxanthin, gut microbiota, and the host intestinal mucosal immunity during the progression of
obesity and T2DM remains. The central hypothesis of this proposal is that dietary zeaxanthin effectively
reduces intestinal immune response and inflammation by the gut microbiota. This project’s objective is to
determine the underlying mechanism by which the zeaxanthin diet, gut microbiome, and host intestinal
mucosal immunity interact to prevent the progression of obesity and T2DM through the following two specific
aims: 1) Determine how dietary zeaxanthins modulate intestinal mucosal immunity through the gut microbiome
in the early stages of obesity and diabetes. 2) Determine mechanistically how the gut microbiota alters the
chemistry of dietary zeaxanthins. The results from this research are expected to provide a deeper
understanding of the bidirectional interaction between dietary zeaxanthins and the gut microbiota-immune axis
in regulating gut health and diseases. These studies will also reveal the importance of the interplay of
zeaxanthin-gut microbiota on host intestinal immunity. Thus, this research will significantly impact public health
by advancing our understanding of dietary intervention of carotenoids in these high-risk populations of obesity
and T2DM. Moreover, completing these studies will further empower RPL's program in microbiology and
immunology and ultimately elevate his career to become an independent NIH PI (e.g., with a funded R01).

## Key facts

- **NIH application ID:** 10771561
- **Project number:** 1P20GM152333-01
- **Recipient organization:** OKLAHOMA STATE UNIVERSITY STILLWATER
- **Principal Investigator:** DINGBO LIN
- **Activity code:** P20 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $248,496
- **Award type:** 1
- **Project period:** 2024-02-01 → 2029-01-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10771561

## Citation

> US National Institutes of Health, RePORTER application 10771561, Microbiome response to dietary carotenoids (1P20GM152333-01). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10771561. Licensed CC0.

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