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HealthyiPROACT-pilotNCT06674018

Indole-3-PROpionic Acid Clinical Trials - a Pilot Study

A study testing Indole-3-propionic acid in people with Healthy, run by Glostrup University Hospital, Copenhagen at 1 site in Denmark.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

The goal of this pilot intervention trial is to investigate the biological effects of daily supplementation with different doses of indole-3-propionic acid (IPA) in healthy adults. Read more about this study

Who is it for?
Ages 18 to 65 yearsHealthy volunteers can take part
Conditions the study is for
Healthy
What is being tested?
Indole-3-propionic acid
Type of treatment
Pill or oral medicine
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
79 participants
Where
1 siteDenmark
Study dates
14 Nov 2024to 25 Feb 2025
Phase
Interventional
Are there results?
None posted in the registry

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 to 65 years
  • All sexes
  • Healthy volunteers accepted
  • Adult, Older adult

Who may be able to join

  • Healthy women and men ≥18 and ≤65 years of age
  • Deemed mentally and physically able to participate

Who cannot join

  • Diagnosis of gut-, heart-, liver-, kidney or immune-related disorders
  • Use of antibiotics within the last month
  • Pregnant or lactating women or birth within the last five months
  • Use of medicine that requires prescription

Trial locations and contacts

1 site in 1 country.

Denmark1 site
  • Optic Neuritis Clinic, Danish Multiple Sclerosis Center, Department of Neurology, Copenhagen University Hospital, Rigshospitalet-Glostrup

    Glostrup Municipality, 2600

Other trials in Denmark

About this study

Official title: Indole-3-PROpionic Acid Clinical Trials - a Pilot Study (iPROACT-pilot)

The goal of this pilot intervention trial is to investigate the biological effects of daily supplementation with different doses of indole-3-propionic acid (IPA) in healthy adults. The main scientific questions are:

  • Does supplementation with IPA increase the abundance regulatory T cells in the blood? Regulatory T cells are believed to play an important role in preventing autoimmune diseases.
  • Does supplementation with IPA increase the concentration of brain-derived neurotrophic factor (BDNF) in the blood? BDNF is believed to play an important role in maintaining brain health.
  • Does supplementation with IPA affect blood analyses commonly performed to assess the risk of metabolic disorders like type 2 diabetes and cardiovascular diseases?
  • How big a dose of IPA is necessary to achieve the above benefits?
Read more

Participants will:

  • Take 50 mg IPA or 120 mg IPA or 500 mg IPA or placebo every morning for 14 days.
  • Visit the clinic at the beginning (day 1) and at the end (day 15) of IPA supplementation to deliver blood, urine and fecal samples, have simple measurements performed, fulfil questionnaires and report any side effects.
Read the detailed description

Indole-3-propionic acid (IPA) is a gut bacterial metabolite with the amino acid tryptophan as substrate. In vitro and animal studies, suggest that IPA could contribute to regulating inflammation and metabolic function, preventing oxidative damage and upregulating expression of brain-derived neurotrophic factor. With this study we aim to investigate the biochemical effects of IPA at supraphysiological levels in humans.

Conditions
Healthy
Being tested
Indole-3-propionic acid, Placebo
Keywords
Indole-3-propionic acid, gut bacterial metabolite, regulatory T cells, brain-derived neurotrophic factor, dietary supplement

What participants receive

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

  • Indole-3-propionic acidDietary supplement

    A dosis of either 50 mg IPA, 120 mg IPA or 500 mg IPA (two capsules) will be taken orally, once daily in the morning after an overnight fast for 14 consecutive days.

  • PlaceboDietary supplement

    Two capsules of placebo will be taken orally, once daily in the morning after an overnight fast for 14 consecutive days.

Study groups in NCT06674018
Study groupRoleWhat they receive
PlaceboPlacebo comparatorPlacebo
Receives: Dietary Supplement: Placebo
50 mg IPAExperimental50 mg indole-3-propionic acid
Receives: Dietary Supplement: Indole-3-propionic acid
120 mg IPAExperimental120 mg indole-3-propionic acid
Receives: Dietary Supplement: Indole-3-propionic acid
500 mg IPAExperimental500 mg indole-3-propionic acid
Receives: Dietary Supplement: Indole-3-propionic acid

What is being measured

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

  1. Regulatory T cells (first primary outcome)

    FoxP3+CD25+CD127- regulatory T cells expressed as a percentage of single, live CD3+CD4+CD8- lymphocytes. Analysed in freshly isolated peripheral blood mononuclear cells using a Symphony A3 flowcytometer.

    Measured: Results from fasting blood samples taken on day 15 and adjusted for results from day 1 (fasting just before first supplement/placebo dosis).

  2. Brain-derived neurotrophic factor (second primary outcome)

    Brain-derived neurotrophic factor measured in plasma samples using ELISA or mesoscale.

    Measured: Results from fasting blood samples taken on day 15 and adjusted for results from day 1 (fasting just before first supplement/placebo dosis).

Secondary outcomes (27)
  1. Flowcytometric profiling of T cells

    T cell profiling of freshly isolated peripheral blood mononuclear cells using a Symphony A3 flowcytometer. Panel antigens: CD3, CD4, CD8, CD45RA, CCR7, CXCR3, CCR6, CCR4, CCR10, CD25, CD127, FoxP3.

    Target populations Th1: CXCR3+CCR4-CCR6-CCR10- Th2: CXCR3-CCR4+CCR6-CCR10- Th17: CXCR3-CCR4+CCR6+CCR10- Th17.1: CXCR3+CCR4-CCR6+CCR10- Th22: CXCR3-CCR4+CCR6+CCR10+ all of the above expressed as a percentage of single, live CD3+CD4+CD8-CD45RA- lymphocytes.

    Furthermore, Th1/Th2 and Th17/Treg ratios will be calculated and the expression of CCR7 will be analysed within the target populations.

    In addition, the expression of the above chemokine receptors will be explored within the population of FoxP3+CD25+C1D127- T regulatory cells. This will allow for monitoring of newly identified T cells subsets such as Th1-like Tregs.

    Lastly, an untargetted approach may be employed to allow for unbiased identification of changes in novel, yet uncharacterized populations.

    Measured: Results from fasting blood samples taken on day 15 and adjusted for results from day 1 (fasting just before first supplement/placebo dosis).

  2. CRP

    C-reactive protein (CRP) measured in plasma (mg/L) as a biomarker of infection and systemic inflammation. Lower-limit of quantification: 0,4 mg/L. Values below 0,4 mg/L are imputed as 0,2 mg/L.

    Measured: Results from blood samples taken on day 15 (just before last supplement/placebo dosis) and adjusted for results from day 1 (just before first supplement/placebo dosis).

  3. Triglycerides

    Plasma triglycerides (mmol/l).

    Measured: Results from fasting blood samples taken on day 15 and adjusted for results from day 1 (fasting just before first supplement/placebo dosis).

  4. non-HDL cholesterol

    Non-HDL cholesterol calculated as total cholesterol minus HDL cholesterol (mmol/l)

    Measured: Results from fasting blood samples taken on day 15 and adjusted for results from day 1 (fasting just before first supplement/placebo dosis).

  5. C-peptide

    Proinsulin C-peptide (pmol/l) measured in plasma.

    Measured: Results from fasting blood samples taken on day 15 and adjusted for results from day 1 (fasting just before first supplement/placebo dosis).

  6. Fasting glucose

    Plasma glucose (mmol/l). Participants abstain from eating and drinking after 22.00 the day before. Only water is allowed. Fasting blood samples are taken between 8.00-10.00 in the morning.

    Measured: Results from fasting blood samples taken on day 15 and adjusted for results from day 1 (fasting just before first supplement/placebo dosis).

  7. Isoprostane-F2-alpha

    Isoprostane-F2-alpha measured in blood or morningurine samples as a marker of lipid oxidation.

    Measured: Results from samples taken on day 15 and adjusted for results from day 1.

  8. 8-oxo-dG

    8-oxo-dG (8-Oxo-2'-deoxyguanosine) measured in blood or morningurine samples as a marker of DNA-related stress damage.

    Measured: Results from samples taken on day 15 and adjusted for results from day 1.

  9. Serum metabolomics

    Targetted and untargetted liquid-chromatography mass-spectrometry-based metabolomics of serum samples. Targetted analyses aim to quantify indole-3-propionic acid and its metabolites (biomarker of compliance as well as absorptive and metabolic capacity), other bacterial- and host metabolites of tryptophan as well as short-chain fatty acids.

    Measured: Four samples in total. Day 1 prior to and again 1.5 hour after intake of first capsule of IPA/ placeblo. Day 15 prior to and again 1.5 hour after intake of last capsule of IPA/ placebo.

  10. Total cholesterol

    Plasma cholesterol (mmol/l).

    Measured: Results from fasting blood samples taken on day 15 and adjusted for results from day 1 (fasting just before first supplement/placebo dosis).

  11. VLDL cholesterol

    Plasma very low-density lipoproteins (mmol/l).

    Measured: Results from fasting blood samples taken on day 15 and adjusted for results from day 1 (fasting just before first supplement/placebo dosis).

  12. LDL cholesterol

    Plasma low-density lipoprotein (LDL) (mmol/l).

    Measured: Results from fasting blood samples taken on day 15 and adjusted for results from day 1 (fasting just before first supplement/placebo dosis).

  13. HDL cholesterol

    Plasma high-density lipoprotein (HDL) (mmol/l).

    Measured: Results from fasting blood samples taken on day 15 and adjusted for results from day 1 (fasting just before first supplement/placebo dosis).

  14. Malondialdehyde

    Malondialdehyde measured in blood or morningurine samples as a marker of oxidative stress.

    Measured: Results from samples taken on day 15 and adjusted for results from day 1.

  15. Protein carbonyls

    Protein carbonyls measured in blood or morningurine samples as a marker of protein oxidation.

    Measured: Results from samples taken on day 15 and adjusted for results from day 1.

  16. Glycated hemoglobin (HbA1c)

    HbA1c (IFCC, mmol/mol) measured in whole blood. Estimated average glucose values (mmol/l) are also calculated automatically from HbA1c by our laboratory.

    Measured: Results from fasting blood samples taken on day 15 and adjusted for results from day 1 (fasting just before first supplement/placebo dosis).

  17. Changes in the gut microbiome

    Characterization of the gut microbiome using molecular biology methods such as 16s rRNA sequencing.

    Measured: Fecal samples are collected at three time points: prior to supplementation (earliest 48 hours prior to first visit (day 1)), short after initiation of supplementation (day 3 or soonest thereafter) and again earliest 48 hours prior to last visit.

  18. Characterization of the metabolic activity of the gut microbiota

    Targetted and untargetted liquid-chromatography mass-spectrometry-based metabolomics. Targetted analyses aim to quantify indole-3-propionic acid, other bacterial- and host metabolites of tryptophan as well as short-chain fatty acids.

    Measured: Fecal samples are collected at three time points: prior to supplementation (earliest 48 hours prior to first visit (day 1)), short after initiation of supplementation (day 3 or soonest thereafter) and again earliest 48 hours prior to last visit.

  19. Bacterial polysaccharides

    Endotoxin, capsular polysaccharides or other bacterial polysaccharides measured in blood samples as biomarker of bacterial translocation across the intestinal epithelium.

    Measured: Results from samples taken on day 15 and adjusted for results from day 1.

  20. Pre-haptoglobin 2

    Measurement of pre-haptoglobin 2 in blood samples as a biomarker of intestinal permeability.

    Measured: Results from samples taken on day 15 and adjusted for results from day 1.

  21. Intestinal fatty acid binding protein

    Measurements of intestinal fatty acid binding protein in blood samples as a biomarker of enterocyte damage.

    Measured: Results from samples taken on day 15 and adjusted for results from day 1.

  22. Citrulline

    Measurement of citrulline in blood samples as a biomarker of intestinal function.

    Measured: Results from samples taken on day 15 and adjusted for results from day 1.

  23. Calprotectin

    Calprotectin measured in fecal samples as a biomarker of intestinal inflammation.

    Measured: Results from samples taken on day 15 and adjusted for results from day 1.

  24. Neopterin

    Neopterin measured in morningurine samples as a biomarker of systemic inflammation.

    Measured: Results from samples taken on day 15 and adjusted for results from day 1.

  25. suPAR

    Soluble urokinase plasminogen activator receptor (suPAR) measured in blood samples.

    Measured: Results from samples taken on day 15 and adjusted for results from day 1.

  26. Microvesicles

    Flow cytometric analyses of microvesicles/ microparticles in platelet-free plasma as biomarker of systemic inflammation.

    Measured: Results from samples taken on day 15 and adjusted for results from day 1.

  27. Endothelial progenitor cells

    Flow cytometric analyses of endothelial progenitor cells measured in platelet-free plasma as biomarker of systemic inflammation

    Measured: Results from samples taken on day 15 and adjusted for results from day 1.

Timeline

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

  1. First posted5 Nov 2024
  2. Study start14 Nov 2024
  3. Primary completion25 Feb 2025
  4. Study completion25 Feb 2025

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
Parallel groups
Masking
Quadruple blind
Who is masked
Participant, Care provider, Investigator, Outcomes assessor
Enrolment
79 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT06674018
Sponsor's protocol ID
H-24008127
Acronym
iPROACT-pilot
Status last verified
Mar 2025
First submitted
2 Nov 2024
Last updated
5 Mar 2025
Results posted
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
Yes: Individual participant data that underlie the results reported in published articles, after deidentification (text, tables, figures, and appendices).

Questions about this trial

What is this clinical trial studying?

A study testing Indole-3-propionic acid in people with Healthy, run by Glostrup University Hospital, Copenhagen at 1 site in Denmark.

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 2 inclusion and 4 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: finished, as of the sponsor's last update on 5 Mar 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 Denmark. 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?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

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?

Regulatory T cells (first primary outcome) (time frame: Results from fasting blood samples taken on day 15 and adjusted for results from day 1 (fasting just before first supplement/placebo dosis).). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?
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 5 Mar 2025.

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