Identifying Terpenoid- and Carotenoid-modifying Enzymes in the Human Gut (NCState)

Phage-Enabled Mining of Gut Metagenomes for Terpenoid and Carotenoid Metabolism

In this study, the investigators will collect fecal samples from healthy adults. The investigators will extract DNA from these fecal samples and use microbiological techniques to determine whether this DNA encodes enzymes that can react with certain chemicals called terpenoids and carotenoids. The investigators will additionally collect dietary information via a questionnaire.

Study Overview

• Status: Completed
• Conditions: Terpene Synthases; Carotenoid Modifying Enzymes
• Intervention / Treatment: Other: No Intervention: Observational Cohort

• Study Type: Observational
• Enrollment (Actual): 40

Contacts and Locations

Study Locations

• United States
  • North Carolina
    • Raleigh, North Carolina, United States, 27606
      • NC State University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

• Sampling Method: Non-Probability Sample

Study Population

Healthy adults

Description

Inclusion Criteria:

• Body Mass index <25

Exclusion Criteria:

• Pregnant
• Taken antibiotics or antifungals in the past 3 months
• Taken probiotic supplements in the past 3 months
• Diarrhea in the past month

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Healthy adults	Other: No Intervention: Observational Cohort; No intervention

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of unique gut metagenomic enzymes with carotenoid-modifying activities for each participant.	Subjects' fecal metagenomic DNA will be extracted from their fecal sample, and random fragments of this metagenomic DNA will be inserted into an E. coli expression vector. This vector library will be transformed into an E. coli strain that will change color if a carotenoid-modifying gene is present. We expect to obtain about one million E. coli clones per participant. These clones will be spread on agar plates, and the colonies exhibiting different colors will be recovered and sequenced. The sequences of each participant will be collected and annotated to determine putative carotenoid-modifying enzymes, and the number of unique enzymes will be saved.	Day 1

Collaborators and Investigators

• Sponsor: North Carolina State University
• Collaborators: National Center for Complementary and Integrative Health (NCCIH)

Study record dates

Study Major Dates

• Study Start (Actual): September 9, 2025
• Primary Completion (Actual): March 1, 2026
• Study Completion (Actual): March 1, 2026

Study Registration Dates

• First Submitted: April 10, 2026
• First Submitted That Met QC Criteria: May 9, 2026
• First Posted (Actual): May 15, 2026

Study Record Updates

• Last Update Posted (Actual): May 20, 2026
• Last Update Submitted That Met QC Criteria: May 16, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Other Study ID Numbers: 27363; R21AT012805 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Fecal samples and data derived from them, including metagenome, metatranscriptome, metaproteome, and metabolome data will be provided to other researchers provided that they agree not to re-identify participants.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No