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

Study Overview
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Brief Summary
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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
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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.

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

Conditions
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Dietary Exposure

Intervention / Treatment
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* Dietary Supplement: L-carnitine supplementation (500 mg per tablet per day, purchased from GNC company)


Participation Criteria
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Eligibility Criteria
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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

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Intervention Model: Single Group Assignment
Interventional Model Description: All participants received L-carnitine supplementation (500 mg per tablet per day, GNC) for one month. Oral carnitine challenge tests and fecal sampling were conducted both before and after the intervention.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: L-carnitine supplementation<br>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. | Dietary Supplement: L-carnitine supplementation (500 mg per tablet per day, purchased from GNC company)<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| TMAO level | plasma and urine TMAO concentrations of oral carnitine challenge test | Before and 1 month after L-carnitine supplementation | 
| Compositional and functional alterations of gut microbiota | 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). | Before and 1 month after L-carnitine supplementation | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Gut microbiota, Trimethylamine N-oxide, L-carnitine supplementation, Oral carnitine challenge test