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HealthyTESSANCT06518343

Trimethylamine N-oxide Effects of a Pomegranate Supplement Simultaneously With Carnitine (TESSA)

A study testing L-carnitine + Pomegranate extract and L-carnitine + Microcrystalline cellulose in people with Healthy, run by Quadram Institute Bioscience at 1 site in United Kingdom.

Active, not recruiting

Under way, not looking for participants. Everyone needed has enrolled. The study is still running.

Official record
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Trial summary

Trimethylamine N-oxide (TMAO) is produced in some individuals whose diets include meat, fish, and dairy.These foods are rich in L-carnitine. L-carnitine is metabolised by the liver and gut microorganisms (bacteria) into TMAO. Read more about this study

Who is it for?
Ages 18 years and olderHealthy volunteers can take part
Conditions the study is for
Healthy
What is being tested?
L-carnitine + Pomegranate extract and L-carnitine + Microcrystalline cellulose
Type of treatment
Pill or oral medicine
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
39 participants
Where
1 siteUnited Kingdom
Study dates
12 Aug 2024to 31 May 2027
Phase
Interventional
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 years and older
  • All sexes
  • Healthy volunteers accepted
  • Adult, Older adult

Who may be able to join

  • Individuals who regularly eat meat (4 portions of meat per week for at least 2 months prior to enrolment in the study).
  • Aged 18 and older.
  • Body Mass Index (BMI) between 18.5 - 30 kg/m2.
  • Living within 40 miles from the Norwich Research Park.
  • meets first phase inclusion criteria
  • TMAO producer (plasma TMAO increase of >5 µM and >50% after L-carnitine ingestion.

Who cannot join

  • Consume an entirely vegan, vegetarian, or pescatarian diet within the last two months.
  • Do not have access to a freezer to store some provided meals and ice packs.
  • Have a known allergy to the tablets, capsules (i.e., pomegranate), or standardised meals such as wheat, eggs, milk, nuts, and soybeans.
  • Have difficulty swallowing, a swallowing disorder, or are unable to swallow four capsules (the size of a peanut) and three L carnitine tablets consecutively within a time span of ten minutes.
  • Have bowel movements less than five times a week.
  • Are a current smoker (or stopped smoking for less than 3 months).
Show all 23Show fewer
  • Consume more than 14 units of alcohol per week (for example, a pint of beer or a 175 mL glass of wine each count as two units).
  • Are pregnant or breastfeeding.
  • Have anaemia or any conditions or medications that may hinder clotting. This will be assessed on a case-by-case basis.
  • Have high or low blood pressure (i.e., ≤90/60 or ≥160/100 mmHg).
  • Have a medical condition or take medications that may affect the primary outcome of this study, such as but not limited to diabetes, liver disease, hypo/hyperthyroidism, or fish odour syndrome. This will be assessed on a case-by-case basis.
  • Have had gastrointestinal disease or surgical procedures that may affect the primary outcome of this study. This will be assessed on a case-by-case basis.
  • Have known or a history of kidney disease, this will be determined by the medical advisor using blood urea nitrogen and creatinine levels in the participant's blood.
  • Regularly use bowel cleansing techniques like colonic irrigation or laxatives.
  • Had an infection or received antibiotics within a month prior to this study.
  • Regularly take dietary supplements that may affect the primary outcome measure of this study, such as fish oil or L carnitine supplements.
  • Are currently undergoing active treatment for cancer or heart disease.
  • Participated in another dietary intervention study within the last four months.
  • Have donated a large quantity of blood within the last 16 weeks. Registered donors should abstain from blood donations for the duration of the study.
  • Are a person related to or living with a member of the study team.
  • Are unable to give written or verbal informed consent.
  • Participant is unable to provide GP (General Practitioner) contact details.
  • Have symptoms of Coronavirus infection (COVID-19), been asked to self-isolate, or have been diagnosed with COVID-19 in the last 14 days.

Trial locations and contacts

1 site in 1 country.

United Kingdom1 site
  • Quadram Institute

    Norwich, Norfolk, NR4 7UQ

Other trials in United Kingdom

About this study

Official title: The Trimethylamine N-oxide (TMAO)-Reducing Effects of a Pomegranate Supplement Simultaneously Administered With L-carnitine

Trimethylamine N-oxide (TMAO) is produced in some individuals whose diets include meat, fish, and dairy.These foods are rich in L-carnitine. L-carnitine is metabolised by the liver and gut microorganisms (bacteria) into TMAO. In the TESSA study, investigators will explore whether pomegranate extract can lower the production of TMAO in healthy men and women. This reduction in TMAO production has been associated with decreasing a person's risk of heart disease.

Read the detailed description

The TESSA study is a 18 day randomised, double-blind, placebo-controlled two-arm crossover pilot study conducted at the NIHR (National Institute for Health and Care Research) Norfolk Clinical Research Facility (CRF) in the Quadram Institute in Norwich. Investigators are seeking men and women over the age of 18 years who habitually consume meat, fish, and/or eggs and are TMAO producers to determine whether pomegranate extract affects L-carnitine metabolism compared to a matched placebo. This study is conducted in two phases. The first phase involves two study visits where investigators will identify and invite TMAO producing individuals to continue to the second phase of this study. Moreover, investigators will ask the participant to complete a food frequency questionnaire. The second phase involves two intervention periods which are separated by a 10 day washout. Each intervention period begins with a run-in followed by three study visits. Investigators will precisely quantify the absorption (blood plasma concentrations over time, pharmacokinetic study) and metabolism of L-carnitine and its products of metabolism which includes TMAO. Additionally, investigators will examine pomegranate metabolism and excretion with timed urine collections and stool samples.

Participants will consume three L-carnitine capsules at the first visit during the first phase. In the second phase, participants will consume L-carnitine capsules with the intervention capsules (pomegranate extract or placebo) for the first intervention period then after the washout period, participants will crossover and consume L-carnitine capsules with the other intervention capsules for the second intervention period. For each intervention period, three L-carnitine capsules with four intervention capsules at the first visit following the run-in. During the second phase starting at the run-in period participants will be asked to follow a standardized, controlled diet which will be low in choline, L-carnitine, and ellagitannins.

Conditions
Healthy
Being tested
L-carnitine + Pomegranate extract, L-carnitine + Microcrystalline cellulose

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • L-carnitine + Pomegranate extractDietary supplement

    Participants will consume 1.5 grams L-carnitine with 1.6 grams pomegranate extract at one visit during one intervention period

  • L-carnitine + Microcrystalline celluloseDietary supplement

    Participants will consume 1.5 grams L-carnitine with 1.5 grams microcrystalline cellulose at one visit during one intervention period

Study groups in NCT06518343
Study groupRoleWhat they receive
Pomegranate extractExperimental1.5 grams L-carnitine (Carnipure®) + 1.6 grams pomegranate extract (Dermogranate®) in hydroxypropyl methylcellulose (HPMC) capsules
Receives: Dietary Supplement: L-carnitine + Pomegranate extract
Microcrystalline cellulosePlacebo comparator1.5 grams L-carnitine (Carnipure®) + 1.5 grams microcrystalline cellulose (MCC, Redwells Health) in hydroxypropyl methylcellulose (HPMC) capsules
Receives: Dietary Supplement: L-carnitine + Microcrystalline cellulose

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Difference in the area under the curve (AUC) of blood plasma TMAO concentrations after pomegranate extract and microcrystalline cellulose interventions.

    Comparison of AUC of blood plasma TMAO concentrations after L-carnitine with pomegranate extract and after L-carnitine with microcrystalline cellulose interventions.

    Measured: Day 2,3,4,16,17,and 18

Secondary outcomes (11)
  1. Changes in area under the curve (AUC) from plasma concentrations of L-carnitine and its metabolites

    Plasma blood concentrations of L-carnitine and its metabolites (γ-BB: γ-butyrobetaine, TMA: trimethylamine, and TMAO) will be quantified after ingestion of L-carnitine and intervention capsules (pomegranate extract or microcrystalline cellulose). AUC will be determined using trapezoidal approximation of plasma concentrations over time. Measurements will be taken 0, 0.5, 1, 1.5, 2, 2.5, 16, 18, 20, 22, 24, and 48 hours after capsules have been ingested on Day 2 and Day 16.

    Measured: 48 hours

  2. Change in peak plasma concentration (Cmax) of L-carnitine and its metabolites

    Plasma blood concentrations of L-carnitine and its metabolites (γ-BB: γ-butyrobetaine, TMA: trimethylamine, and TMAO) will be quantified after ingestion of L-carnitine and intervention capsules (pomegranate extract or microcrystalline cellulose). Cmax will be the highest concentration measured during a 48 hour period. Measurements will be taken 0, 0.5, 1, 1.5, 2, 2.5, 16, 18, 20, 22, 24, and 48 hours after capsules have been ingested on Day 2 and Day 16.

    Measured: 48 hours

  3. Change in the time to reach peak plasma concentration (Tmax) of L-carnitine and its metabolites

    Plasma blood concentrations of L-carnitine and its metabolites (γ-BB: γ-butyrobetaine, TMA: trimethylamine, and TMAO) will be quantified after ingestion of L-carnitine and intervention capsules (pomegranate extract or microcrystalline cellulose). Tmax will be the time when peak concentration of L-carnitine or its metabolites has been reached. Measurements will be taken 0, 0.5, 1, 1.5, 2, 2.5, 16, 18, 20, 22, 24, and 48 hours after capsules have been ingested on Day 2 and Day 16.

    Measured: 48 hours

  4. Change in plasma half-life (t1/2) of L-carnitine and its metabolites

    Plasma blood concentrations of L-carnitine and its metabolites (γ-BB: γ-butyrobetaine, TMA: trimethylamine, and TMAO) will be quantified after ingestion of L-carnitine and intervention capsules (pomegranate extract or microcrystalline cellulose). Half life will be the time point where concentration of L-carnitine or its metabolites have reduced by half. Measurements will be taken 0, 0.5, 1, 1.5, 2, 2.5, 16, 18, 20, 22, 24, and 48 hours after capsules have been ingested on Day 2 and Day 16.

    Measured: 48 hours

  5. Change in the area under the curve (AUC) from urine concentrations of L-carnitine and its metabolites

    Urine concentrations of L-carnitine and its metabolites (γ-BB: γ-butyrobetaine, TMA: trimethylamine, and TMAO) will be quantified after ingestion of L-carnitine and intervention capsules (pomegranate extract or microcrystalline cellulose). AUC will be determined using trapezoidal approximation of plasma concentrations over time. Measurements will be taken from urine collections at 0, 2, 2.5 to 16, 18, 20, 22, 24, and 24 to 48 hours.

    Measured: 48 hours

  6. Change in pomegranate polyphenols and their metabolite concentrations from pooled 24 hour urine collections.

    Quantification of pomegranate polyphenols and their metabolite excretion into urine will be measured from pooled urine collections (24 and 48 hours) using targeted metabolite analysis of pomegranate polyphenols, punicalagin, ellagic acid, urolithins. These metabolites will be used to define relationships between dietary intake, pomegranate metabolism and pharmacokinetic outcomes

    Measured: Day 3, 4, 17, and 18.

  7. Difference in L-carnitine and its metabolites concentrations from faecal (stool) collections after pomegranate extract and microcrystalline cellulose interventions.

    Comparison in L-carnitine and and its metabolite (γ-BB: γ-butyrobetaine, TMA: trimethylamine, and TMAO) excretion into faeces (stool) will be measured from faecal samples at baseline and after each intervention period. These metabolites will be used to define relationships between dietary intake, L-carnitine metabolism and microbiome composition

    Measured: Day 2, 4, and 18.

  8. Changes in gut microbiota composition (indices of diversity and in taxonomic abundances) over study duration

    Comparison of gut microbiota composition will be determined using indices of diversity and taxonomic abundances using Shotgun metagenomic sequencing of faecal samples collected at the start and end of each intervention period.

    Measured: Day 2, 4, 16, and 18.

  9. Treatment effects of gut microbiota composition (indices of diversity and in taxonomic abundances) after pomegranate extract and microcrystalline cellulose interventions.

    Comparison of gut microbiota composition will be determined using indices of diversity and taxonomic abundances using Shotgun metagenomic sequencing of faecal samples collected at the end of each intervention period.

    Measured: Day 4 and 18.

  10. Difference in bacterial transcripts from faecal (stool) collections after pomegranate extract and microcrystalline cellulose interventions.

    Comparison of absolute abundance of L-carnitine metabolising bacterial genes and their transcripts using specific qPCR (quantitative polymerase chain reaction) and RT-qPCR (Real-time polymerase chain reaction) assays from faecal samples collected at baseline and after each intervention period.

    Measured: Day 2, 4, and 18.

  11. Correlation between plasma TMAO concentration and quantity of L carnitine-rich foods consumed in habitual diets of healthy men and women.

    Plasma TMAO concentration measured during the first phase of this study will be correlated (Pearson correlation) with the quantity of L-carnitine-rich foods collected from a 90-day Food Frequency Questionnaire (VioCare VioScreen).

    Measured: Phase 1 Day 2

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted24 Jul 2024
  2. Study start12 Aug 2024
  3. Primary completion31 May 2027 (estimated)
  4. Study completion31 May 2027 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Basic science
Allocation
Randomised
Intervention model
Crossover
Model description
Crossover Assignment
Masking
Triple blind
Who is masked
Participant, Investigator, Outcomes assessor
Enrolment
39 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT06518343
Sponsor's protocol ID
QIB01/2024
Other IDs
336410
Acronym
TESSA
Status last verified
Jul 2024
First submitted
19 Jul 2024
Last updated
15 Jun 2025
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Publications

  • Haarhuis JE, Ahn-Jarvis J, Savva GM, Day-Walsh PE, Ferns C, Hughes S, Triller S, Al-Jaibaji O, Philo M, Acaroz E, Perez-Moral N, Kroon PA. Effect of a polyphenol-rich pomegranate extract on plasma trimethylamine N-oxide levels following an oral carnitine challenge: a randomized controlled crossover trial in healthy adults. Front Nutr. 2026 May 20;13:1822840. doi: 10.3389/fnut.2026.1822840. eCollection 2026.

    PubMed 42293209

Questions about this trial

What is this clinical trial studying?

A study testing L-carnitine + Pomegranate extract and L-carnitine + Microcrystalline cellulose in people with Healthy, run by Quadram Institute Bioscience at 1 site in United Kingdom.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 6 inclusion and 23 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: under way, not looking for participants, as of the sponsor's last update on 15 Jun 2025. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in United Kingdom. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Difference in the area under the curve (AUC) of blood plasma TMAO concentrations after pomegranate extract and microcrystalline cellulose interventions. (time frame: Day 2,3,4,16,17,and 18). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT06518343, which also lists 1 linked publication.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 15 Jun 2025.

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