Clinical trial NCT02838732: Investigation on the Effect of Carnitine Supplement on Gut Microbiota and TMAO Production Capacity
Official title: Investigation on the Effect of Carnitine Supplement on Gut Microbiota and TMAO Production Capacity
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Dietary Exposure
Keywords: Gut microbiota
Trimethylamine N-oxide
L-carnitine supplementation
Oral carnitine challenge test
Lead sponsor: National Taiwan University Hospital
Sponsor class: OTHER
First posted: 2016-07-20
Enrollment: 56
Sex: ALL
Minimum age (years): 20
Maximum age (years): 65
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: NA
Intervention model: SINGLE_GROUP
Intervention 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.
Primary purpose: BASIC_SCIENCE

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.

Eligibility criteria: 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

Primary outcomes:
measure: TMAO level
timeFrame: Before and 1 month after L-carnitine supplementation
measure: Compositional and functional alterations of gut microbiota
timeFrame: Before and 1 month after L-carnitine supplementation
Secondary outcomes:
Other outcomes:
Locations:
city: Taipei
country: Taiwan
facility: National Taiwan University Hospital
Study officials:
affiliation: National Taiwan University Hospital
name: Ming-Shiang Wu, MD, PhD
role: STUDY_DIRECTOR
References:
citation: Wu WK, Chen CC, Liu PY, Panyod S, Liao BY, Chen PC, Kao HL, Kuo HC, Kuo CH, Chiu THT, Chen RA, Chuang HL, Huang YT, Zou HB, Hsu CC, Chang TY, Lin CL, Ho CT, Yu HT, Sheen LY, Wu MS. Identification of TMAO-producer phenotype and host-diet-gut dysbiosis by carnitine challenge test in human and germ-free mice. Gut. 2019 Aug;68(8):1439-1449. doi: 10.1136/gutjnl-2018-317155. Epub 2018 Oct 30.