# Molecular characterization of the ocular microbiome in healthy adults

> **NIH NIH U24** · VANDERBILT UNIVERSITY MEDICAL CENTER · 2024 · $656,201

## Abstract

SUMMARY
The ocular surface is constantly exposed to the environment and is inhabited by several microbes.
The most commonly used methods for ocular surface microbiome characterization consist of
traditional microbiological culturing and, more recently, next-generation sequencing. Culture-based
methods provide information on absolute abundances but are limited in identifying only fast-growing
microorganisms on culture media and a large number of nonculturable microbes. Recent 16S rRNA
marker gene sequencing studies provide the most extensive and diverse characterization of the
ocular microbiome. This data suggests the existence of the resident ocular microbiome; however,
little is known about the core microbiome constituents of the anterior segment in a healthy population.
Furthermore, the optimal method of sample collection that will yield the most representative results
remains unclear. This study aims to implement whole-metagenome sequencing (WMS) and
metatranscriptomics sequencing methods optimized for low-biomass samples to characterize the
ocular microbiome inhabiting the anterior segment of the eye and their interaction with the immune
system in healthy adults. In this project, we will establish a large human cohort (n=500) and will
prospectively collect serial samples from inferior and superior conjunctival fornix from healthy adults
for a period of 1 year. In addition to characterizing the core ocular microbiome in healthy adults, we
will examine seasonal changes in the diversity and enrichment of specific microbial taxon (bacteria,
fungi, and viruses); ocular microbiome differences between sexes and different age groups (young
adults, middle age, and older adults). The metatranscriptomics data will enable us to profile active
microbial pathways (bacteria, fungi, and virus) and host epithelial (conjunctival) immune response for
underpinning associations between the microbiome and ocular immune modulation. The outcomes of
this study will contribute towards understanding the core microbial constituents in the anterior
segment and their role in immune interactions to maintain homeostasis.

## Key facts

- **NIH application ID:** 10874665
- **Project number:** 5U24EY035075-02
- **Recipient organization:** VANDERBILT UNIVERSITY MEDICAL CENTER
- **Principal Investigator:** Sapna S Gangaputra
- **Activity code:** U24 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $656,201
- **Award type:** 5
- **Project period:** 2023-07-01 → 2026-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10874665

## Citation

> US National Institutes of Health, RePORTER application 10874665, Molecular characterization of the ocular microbiome in healthy adults (5U24EY035075-02). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/10874665. Licensed CC0.

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