Indole-3-PROpionic Acid Clinical Trials - a Pilot Study Part 2
- Conditions
- Healthy
- Registration Number
- NCT07105514
- Lead Sponsor
- Glostrup University Hospital, Copenhagen
- Brief Summary
The goal of this trial is to investigate the biological effects of oral supplementation with indole-3-propionic acid (IPA) taken twice daily in healthy adults. The main scientific questions are:
* Does supplementation with IPA increase the abundance of 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?
Participants will:
* Take capsules to achieve a total daily dose of 1000 mg of IPA or placebo: 500 mg every morning and 500 mg every evening for 14 days.
* Visit the clinic at the beginning (day 1) and at the end (day 15) of the supplementation period to deliver blood, urine and fecal samples, have simple measurements performed, fulfil questionnaires and report any side effects.
- 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.
Recruitment & Eligibility
- Status
- RECRUITING
- Sex
- All
- Target Recruitment
- 32
- Healthy women and men ≥18 and ≤65 years of age
- Deemed mentally and physically able to participate
- Diagnosis of gut-, heart-, liver-, kidney or immune-related disorders
- Use of antibiotics within the last month
- Pregnancy, lactation or childbirth within the last five months
- Use of prescription medication
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- PARALLEL
- Primary Outcome Measures
Name Time Method Regulatory T cells (first primary outcome) Results from fasting blood samples taken on day 15 and adjusted for results from day 1 (fasting just before first supplement/placebo dose). 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.
Brain-derived neurotrophic factor (second primary outcome) Results from fasting blood samples taken on day 15 and adjusted for results from day 1 (fasting just before first supplement/placebo dose). Brain-derived neurotrophic factor measured in platelet-free plasma samples using ELISA or mesoscale.
- Secondary Outcome Measures
Name Time Method Th1/Th2 ratio in PBMCs Results from fasting blood samples taken on day 15 and adjusted for results from day 1 (fasting just before first supplement/placebo dose). Th1/Th2 ratio calculated from T cell profiling of freshly isolated peripheral blood mononuclear cells (PBMCs) using a Symphony A3 flowcytometer.
Th1 cells are defined as the CXCR3+CCR4-CCR6-CCR10- non-Treg population and expressed as a percentage of single, live CD3+CD4+CD8-CD45RA- lymphocytes.
Th2 cells are defined as the CXCR3-CCR4+CCR6-CCR10- non-Treg population and expressed as a percentage of single, live CD3+CD4+CD8-CD45RA- lymphocytes.
Panel antigens: FVS780, CD3, CD4, CD8, CD45RA, CCR7, CXCR3, CCR6, CCR4, CCR10, CD25, CD127, FoxP3.Th17/mTreg ratio in PBMCs Results from fasting blood samples taken on day 15 and adjusted for results from day 1 (fasting just before first supplement/placebo dose). Th17/mTreg ratio calculated from T cell profiling of freshly isolated peripheral blood mononuclear cells (PBMCs) using a Symphony A3 flowcytometer.
Th17 cells are defined as the CXCR3-CCR4+CCR6+CCR10- non-Treg population and expressed as a percentage of single, live CD3+CD4+CD8-CD45RA- lymphocytes.
mTreg (memory Tregs) are defined as the FoxP3+CD25+CD127-CD45RA- population and expressed as a percentage of single, live CD3+CD4+CD8-CD45RA- lymphocytes
Panel antigens: FVS780, CD3, CD4, CD8, CD45RA, CCR7, CXCR3, CCR6, CCR4, CCR10, CD25, CD127, FoxP3.Th17.1 cells in PBMCs Results from fasting blood samples taken on day 15 and adjusted for results from day 1 (fasting just before first supplement/placebo dose). Th17.1 cells in freshly isolated peripheral blood mononuclear cells (PBMCs) characterized using a Symphony A3 flowcytometer.
Th17.1 cells are defined as the CXCR3+CCR4-CCR6+CCR10- non-Treg population and expressed as a percentage of single, live CD3+CD4+CD8-CD45RA- lymphocytes
Panel antigens: FVS780, CD3, CD4, CD8, CD45RA, CCR7, CXCR3, CCR6, CCR4, CCR10, CD25, CD127, FoxP3.CRP Results from blood samples taken on day 15 (just before last supplement/placebo dose) and adjusted for results from day 1 (just before first supplement/placebo dose). 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.
Triglycerides Results from fasting blood samples taken on day 15 and adjusted for results from day 1 (fasting just before first supplement/placebo dose). Plasma triglycerides (mmol/l).
non-HDL cholesterol Results from fasting blood samples taken on day 15 and adjusted for results from day 1 (fasting just before first supplement/placebo dose). Non-HDL cholesterol calculated as total cholesterol minus HDL cholesterol (mmol/l)
C-peptide Results from fasting blood samples taken on day 15 and adjusted for results from day 1 (fasting just before first supplement/placebo dose). Proinsulin C-peptide (pmol/l) measured in plasma.
Fasting glucose Results from fasting blood samples taken on day 15 and adjusted for results from day 1 (fasting just before first supplement/placebo dose). 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.
F2-isoprostanes Results from samples taken on day 15 and adjusted for results from day 1. F2-isoprostanes with a specific focus on 8-iso-prostaglandin F2α measured in blood or morningurine samples as a marker of lipid oxidation.
8-oxo-dG Results from samples taken on day 15 and adjusted for results from day 1. 8-oxo-dG (8-Oxo-2'-deoxyguanosine) measured in blood or morningurine samples as a marker of DNA-related stress damage.
Serum metabolomics 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. 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.
Total cholesterol Results from fasting blood samples taken on day 15 and adjusted for results from day 1 (fasting just before first supplement/placebo dose). Plasma cholesterol (mmol/l).
VLDL cholesterol Results from fasting blood samples taken on day 15 and adjusted for results from day 1 (fasting just before first supplement/placebo dose). Plasma very low-density lipoproteins (mmol/l).
LDL cholesterol Results from fasting blood samples taken on day 15 and adjusted for results from day 1 (fasting just before first supplement/placebo dose). Plasma low-density lipoprotein (LDL) (mmol/l).
HDL cholesterol Results from fasting blood samples taken on day 15 and adjusted for results from day 1 (fasting just before first supplement/placebo dose). Plasma high-density lipoprotein (HDL) (mmol/l).
Malondialdehyde Results from samples taken on day 15 and adjusted for results from day 1. Malondialdehyde measured in blood or morningurine samples as a marker of oxidative stress.
Protein carbonyls Results from samples taken on day 15 and adjusted for results from day 1. Protein carbonyls measured in blood or morningurine samples as a marker of protein oxidation.
Glycated hemoglobin (HbA1c) Results from fasting blood samples taken on day 15 and adjusted for results from day 1 (fasting just before first supplement/placebo dose). HbA1c (IFCC, mmol/mol) measured in whole blood. Estimated average glucose values (mmol/l) are also calculated automatically from HbA1c by our laboratory.
T cell profiling Results from fasting blood samples taken on day 15 and adjusted for results from day 1 (fasting just before first supplement/placebo dose). Targetted and untargetted T cell profiling of freshly isolated peripheral blood mononuclear cells (PBMCs) using a Symphony A3 flowcytometer. Panel antigens: FVS780, CD3, CD4, CD8, CD45RA, CCR7, CXCR3, CCR6, CCR4, CCR10, CD25, CD127, FoxP3.
Target populations:
Naïve: CD45RA+CCR7+, Central memory: CD45RA-CCR7+, Effector memory: CD45RA-CCR7-, TEMRA: CD45RA+CCR7-, 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+, as well as expression of chemokine receptors on cytotoxic T cells and regulatory T cells.
An untargetted approach may be employed to allow for unbiased identification of changes in novel, yet uncharacterized populations.Changes in the gut microbiome 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. Characterization of the gut microbiome using molecular biology methods such as 16s rRNA sequencing.
Characterization of the metabolic activity of the gut microbiota 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. 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.
Bacterial polysaccharides Results from samples taken on day 15 and adjusted for results from day 1. Endotoxin, capsular polysaccharides or other bacterial polysaccharides measured in blood samples as biomarker of bacterial translocation across the intestinal epithelium.
Pre-haptoglobin 2 Results from samples taken on day 15 and adjusted for results from day 1. Measurement of pre-haptoglobin 2 in blood samples as a biomarker of intestinal permeability.
Intestinal fatty acid binding protein Results from samples taken on day 15 and adjusted for results from day 1. Measurements of intestinal fatty acid binding protein in blood samples as a biomarker of enterocyte damage.
Citrulline Results from samples taken on day 15 and adjusted for results from day 1. Measurement of citrulline in blood samples as a biomarker of intestinal function.
Calprotectin Results from samples taken on day 15 and adjusted for results from day 1. Calprotectin measured in fecal samples as a biomarker of intestinal inflammation.
Neopterin Results from samples taken on day 15 and adjusted for results from day 1. Neopterin measured in morningurine samples as a biomarker of systemic inflammation.
suPAR Results from samples taken on day 15 and adjusted for results from day 1. Soluble urokinase plasminogen activator receptor (suPAR) measured in blood samples.
Microvesicles Results from samples taken on day 15 and adjusted for results from day 1. Flow cytometric analyses of microvesicles/ microparticles in platelet-free plasma as biomarker of systemic inflammation.
Endothelial progenitor cells Results from samples taken on day 15 and adjusted for results from day 1. Flow cytometric analyses of endothelial progenitor cells measured in platelet-free plasma as biomarker of systemic inflammation
Trial Locations
- Locations (1)
Optic Neuritis Clinic, Danish Multiple Sclerosis Center, Department of Neurology, Copenhagen University Hospital, Rigshospitalet-Glostrup
🇩🇰Glostrup, Denmark
Optic Neuritis Clinic, Danish Multiple Sclerosis Center, Department of Neurology, Copenhagen University Hospital, Rigshospitalet-Glostrup🇩🇰Glostrup, DenmarkJette Lautrup Frederiksen, Prof, MDPrincipal Investigator