Development of Microbial Metabolism Gene Tests for Facilitating Precision Health and Preventive Medicine-Evaluation of TMAO Production in Human Body From High-carnitine Diet by Fecal Gbu Gene Testing

Evaluation of TMAO Production in Human Body From High-carnitine Diet by Fecal Gbu Gene Testing

The risk of cardiovascular diseases from red meat consumption varies among individuals due to variations in gut microbiota. L-carnitine in red meat can be converted to Trimethylamine n-oxide (TMAO) in the body by certain bacteria. Not everyone experiences a significant increase in TMAO levels after consuming carnitine. Gut microbiota differences are observed between high and low TMAO producers. The presence of the γ-butyrobetaine utilization (gbu) gene in gut microbiota is linked to TMAO production. This clinical research aims to determine if the gbu gene can predict TMAO levels after intaking a large amount of red meat.

Study Overview

• Status: Not yet recruiting
• Conditions: Gut Dysbiosis for TMAO Production From Red Meat Consumption
• Intervention / Treatment: Other: Beef

Detailed Description

The risk of developing cardiovascular diseases due to the consumption of red meat varies among individuals, and this may be attributed to differences in the composition and function of gut microbiota. Studies have found that red meat, rich in L-carnitine, may be metabolized by certain anaerobic bacteria in the intestines to produce trimethylamine N-oxide (TMAO) in the human body. Previous research utilizing the oral carnitine challenge test (OCCT) revealed that not everyone experiences a significant increase in blood TMAO levels after consuming carnitine. Moreover, individuals with high TMAO production and low TMAO production showed distinct differences in their gut microbiota.

Furthermore, we have discovered a significant correlation between the abundance of the gbu gene in gut microbiota and the production of TMAO in response to dietary carnitine intake. Therefore, through the design of clinical research, we aim to investigate and assess whether the abundance of the gbu gene in gut microbiota can predict the levels of TMAO produced in the human body under a large amount of red meat consumption.

• Study Type: Interventional
• Enrollment (Estimated): 65
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Wei-Kai Wu, MD/PhD; Phone Number: +886958880236; Email: weikaiwu@ntu.edu.tw

Study Locations

• Taiwan
  • Taipei, Taiwan
    • National Taiwan University Hospital
    • Contact: Wei-Kai Wu, MD/PhD; Phone Number: +886-2-3366-9314; Email: weikaiwu@ntu.edu.tw

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Adult with age between 18 to 70
• Willing and capable of intaking a large amount of beef

Exclusion Criteria:

• Antibiotics use within one month
• L-carnitine supplement use within one month
• Chronic diarrhea
• Myasthenia gravis
• Parathyroid disorders
• Chronic kidney disease
• Epilepsy
• Severe anemia
• Severe cardiovascular diseases.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Red meat tolerance test; Participants are required to take 900 grams of beef in a meal. Before the intervention, participants are asked to dietary record two day before the intervention. Fecal samples will be collected before and after the intervention. Blood sample will be collected in 0hr, 24hr, 48hr after the intervention. Each participant needs to complete a food frequency questionnaire.

Other: Beef; 900 grams of lean beef

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Gut microbiome profiles measured by shotgun metagenome sequencing	up to 7-10 days
Fecal gbu gene abundance measured by qPCR	up to 7-10 days
Blood TMAO level measured by LC-MS/MS	before intervention, 24hr, 48hr after intervention
Platelet aggregation of blood by Light Transmission Aggregometry	up to 7-10 days

Secondary Outcome Measures

Outcome Measure	Time Frame
Carnitine intake measured by 24hr dietary record	up to 7-10 days

Collaborators and Investigators

• Sponsor: National Taiwan University Hospital

Study record dates

Study Major Dates

• Study Start (Estimated): January 15, 2026
• Primary Completion (Estimated): June 20, 2026
• Study Completion (Estimated): November 30, 2026

Study Registration Dates

• First Submitted: December 22, 2025
• First Submitted That Met QC Criteria: December 22, 2025
• First Posted (Estimated): January 7, 2026

Study Record Updates

• Last Update Posted (Actual): January 8, 2026
• Last Update Submitted That Met QC Criteria: January 6, 2026
• Last Verified: December 1, 2025

More Information

Terms related to this study

• Keywords: cardiovascular disease; gut microbiota; carnitine; TMAO; red meat; gbu gene cluster
• Additional Relevant MeSH Terms: Cardiovascular Diseases; Food; Diet, Food, and Nutrition; Physiological Phenomena; Food and Beverages; Meat; Red Meat
• Other Study ID Numbers: 202507141RINB

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: The data will be uploaded to be public when the research is published

Drug and device information, study documents

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