Investigation on the Effect of Carnitine Supplement on Gut Microbiota and TMAO Production Capacity

Not Applicable

Completed

• Conditions: Dietary Exposure
• Interventions: Dietary Supplement: L-carnitine supplementation (500 mg per tablet per day, purchased from GNC company)

• Registration Number: NCT02838732
• Lead Sponsor: National Taiwan University Hospital

Brief Summary

In this project, the investigators aim to explore the impact of dietary L-carnitine supplementation on the TMAO production capacity of gut microbiota.

Detailed Description

Recent studies have established plasma trimethylamine N-oxide (TMAO) levels as a strong, independent risk factor for cardiovascular disease. TMAO is produced by the interaction between gut microflora and ingested L-carnitine from food. Research indicates that both plasma TMAO concentration and the TMAO production capacity of gut microbiota in vegetarians are significantly lower than in omnivores, likely due to the reduced L-carnitine intake in vegetarian diets. This study aims to explore the impact of L-carnitine supplementation on the TMAO production capacity of human gut microbiota and to identify TMAO-producing bacteria within the gut microflora. The study plans to recruit both omnivore and vegetarian volunteers to undergo a one-month L-carnitine supplementation, followed by an evaluation of changes in TMAO production using an oral L-carnitine challenge test, along with gut microbiota assessment. TMAO concentration will be measured using LC-MS/MS, and gut microbiome analysis will be conducted through shotgun metagenome sequencing. Bioinformatic analysis may reveal potential TMAO-producing bacteria. Understanding the changes in TMAO production and gut microbiota composition post-L-carnitine supplementation may enhance our knowledge of the interplay between L-carnitine supplements, TMAO, and gut microflora.

Study Timeline

• Study Start: 2016-05-18
• Study First Submitted: 2016-07-08
• Study First Submitted QC: 2016-07-17
• Study First Posted: 2016-07-20
• Primary Completion: 2017-11-20
• Study Completion: 2019-10-07
• Status Verified: 2023-12
• Last Update Submitted: 2023-12-10
• Last Update Posted: 2023-12-18

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 56

Inclusion Criteria

• Healthy subjects aged 20 to 65 years old
• no usage of antibiotics within one month
• no use of carnitine supplement within one month

Exclusion Criteria

• having serious GI disorder
• medical history of myasthenia gravis
• history of diabetes,
• history of hyperparathyroidism,
• history of chronic kidney disease
• history of epilepsy
• history of severe anemia

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
L-carnitine supplementation	L-carnitine supplementation (500 mg per tablet per day, purchased from GNC company)	All participants received L-carnitine supplementation (500 mg per tablet per day, provided by GNC) for one month. Oral carnitine challenge tests and fecal sampling were conducted both before and after the intervention.

Primary Outcome Measures

Name	Time	Method
Compositional and functional alterations of gut microbiota	Before and 1 month after L-carnitine supplementation	The compositional and functional changes of gut microbiota will be evaluated by shotgun metagenome sequencing. Taxonomy will be calculated as relative abundance of species-level genome bins (SGBs) and specific bacteria genes will be quantified as Reads Per Kilobase per Million (RPKM).
TMAO level	Before and 1 month after L-carnitine supplementation	plasma and urine TMAO concentrations of oral carnitine challenge test

Trial Locations

Locations (1)

National Taiwan University Hospital; 🇨🇳 Taipei, Taiwan