Gut MicrobiomePhase 4NCT06433310
Understanding the Efficacy of Dietary Supplement on Fungal Mycobiota in Healthy Volunteers: A Pilot Study
A Phase 4 study testing L-Phenylalanine 500 mg Veg Capsule product in people with Gut Microbiome and Gut Health, run by Weill Medical College of Cornell University at 1 site in United States.
Trial summary
The purpose of this study is to explore how the dietary supplement L-Phenylalanine affects the production of the metabolite phenylpropionic acid (PPA) and changes fungal populations of the gut microbiome. Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Gut Microbiome, Gut Health, Dietary Supplement
- What is being tested?
- L-Phenylalanine 500 mg Veg Capsule product
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 20 participants
- Where
- 1 siteUnited States
- Study dates
- 17 Oct 2024to 31 Dec 2027
- Phase
- Phase 4
- 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
- Male or female adults over the age of 18 years
Who cannot join
- History of a diagnosis of any gastrointestinal condition, such as inflammatory bowel syndrome or disease
- Antibiotic usage within the past two weeks
- Antifungal usage within the past month
- Allergy to L-Phenylalanine or individuals with phenylketonuria (PKU)
- Adults taking medications known to interact with L-phenylalanine supplements, such as Monoamine Oxidase Inhibitors (MOAI), L-DOPA, and some antipsychotic drugs (complete and extensive drug list will be provided to interested participants during screening)
- Pregnant or nursing women
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
Belfer Research Building
New York, New York, 10022
Emilia T Vignogna, BS, 505-259-4995, etv4001@med.cornell.edu
Iliyan D Iliev, PhD
About this study
The purpose of this study is to explore how the dietary supplement L-Phenylalanine affects the production of the metabolite phenylpropionic acid (PPA) and changes fungal populations of the gut microbiome.
Read the detailed description
The human gastrointestinal tract hosts a diverse microbial community that has a role in influencing the host's pathophysiological responses. Although there is an abundance of metagenomic data available, the functional dynamics of the gut microbiota still need exploration in different conditions. The microbiota produces various metabolites from dietary products, impacting both host health and pathophysiological functions. The metabolites produced by different microbiota may selectively suppress or stimulate the growth of some components of the gut microbiome, ultimately influencing the dynamic of gut bacterial and fungal populations. Our lab is specifically interested in a metabolite, known as phenylpropionic acid (PPA) produced by a human gut resident bacteria known as Clostridium sporogenes. C. sporogenes produces PPA by metabolizing the amino acid, L-phenylalanine, which is sourced from human diet. Many studies have observed the antimicrobial and antifungal effects of PPA. Our lab determined PPA holds antifungal activity of PPA in the gut of mice colonized with Candida albicans. We are interested in investigating how diversity in the mycobiota populations, which focuses on the fungi species in the human gut, are related to changes in PPA levels.
Therefore, this study will asses whether additional oral supplementation of L-phenylalanine has an effect on the way gut mycobiota responds to this amino acid. Healthy subjects received a 14-day supply of L-phenylalanine supplements and provided stool and blood samples to the study team.
- Being tested
- L-Phenylalanine 500 mg Veg Capsule product
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
L-Phenylalanine 500 mg Veg Capsule productDrug
500 mg Veg Capsule product
| Study group | Role | What they receive |
|---|---|---|
| Healthy | Experimental | Participants will receive one bottle of L-Phenylalanine 500 mg Veg Capsule product on Day 0. All subjects will be asked to start taking the supplement on Day 1 continuing until Day 14. They will be asked to take 2x 500 mg capsules in the morning and 1x 500 mg capsule in the evening daily for 14 days. Receives: Drug: L-Phenylalanine 500 mg Veg Capsule product |
What is being measured
The primary outcome is the main question the study is designed to answer.
Changes in phenylpropionic acid levels from baseline in subject fecal material
Metabolite phenylpropionic acid levels will be measured using mass spectrometry before (baseline) and after intervention
Measured: Baseline, Week 2 (Day 14)
Change in fungal population levels, specifically gut Candida levels, from baseline in subject fecal material and swabs
Fungal populations, including Candida, will be measured using microbiota sequencing before (baseline) and after intervention. The most abundant fungal populations will be reported; however, the identity of those populations won't be known until sample analysis.
Measured: Baseline, Week 2 (Day 14)
Change in the number of T cells that react to fungal antigens from baseline in subject blood samples
Blood will be processed through ELISA-based and in vitro restimulation assays to measure T cell reactivity to fungal antigens
Measured: Baseline, Week 2 (Day 14)
Secondary outcomes (3)
Change in phenylpropionic acid levels from baseline in subject fecal material
Metabolite phenylpropionic acid levels will be measured using mass spectrometry before (baseline) and after intervention
Measured: Baseline, Week 4 (Day 28)
Change in fungal population levels, specifically gut Candida levels, from baseline in subject fecal material
Fungal populations, including Candida, will be measured using microbiota sequencing before (baseline) and after intervention. The most abundant fungal populations will be reported; however, the identity of those populations won't be known until sample analysis.
Measured: Baseline, Week 4 (Day 28)
Change in the number of T cells that react to fungal antigens from baseline in subject blood samples
Blood will be processed through ELISA-based and in vitro restimulation assays to measure T cell reactivity to fungal antigens
Measured: Baseline, Week 4 (Day 28)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted29 May 2024
- Study start17 Oct 2024
- Primary completion17 Dec 2027 (estimated)
- Study completion31 Dec 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Gut MicrobiomeStudies of the same condition, open and under way.
- More trials run by Weill Medical College of Cornell UniversityThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
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 4
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 20 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Weill Medical College of Cornell University
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Iliyan D Iliev, PhD, Principal investigator, Weill Medical College of Cornell University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06433310
- Sponsor's protocol ID
- 23-09026469
- Status last verified
- Jun 2026
- First submitted
- 22 May 2024
- Last updated
- 26 Jun 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 26 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Understanding the Efficacy of Dietary Supplement on Fungal Mycobiota in Healthy Volunteers: A Pilot Study
- ClinicalTrials.gov ID
- NCT06433310
- Acronym / sponsor ID
- 23-09026469
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 20 participants (estimated)
- Lead sponsor
- Weill Medical College of Cornell UniversityUniversity, hospital or other
- Study start
- 17 Oct 2024 (actual)
- Primary completion
- 17 Dec 2027 (estimated)
- Study completion
- 31 Dec 2027 (estimated)
- First posted
- 29 May 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The purpose of this study is to explore how the dietary supplement L-Phenylalanine affects the production of the metabolite phenylpropionic acid (PPA) and changes fungal populations of the gut microbiome.
Detailed description
The human gastrointestinal tract hosts a diverse microbial community that has a role in influencing the host's pathophysiological responses. Although there is an abundance of metagenomic data available, the functional dynamics of the gut microbiota still need exploration in different conditions. The microbiota produces various metabolites from dietary products, impacting both host health and pathophysiological functions. The metabolites produced by different microbiota may selectively suppress or stimulate the growth of some components of the gut microbiome, ultimately influencing the dynamic of gut bacterial and fungal populations. Our lab is specifically interested in a metabolite, known as phenylpropionic acid (PPA) produced by a human gut resident bacteria known as Clostridium sporogenes. C. sporogenes produces PPA by metabolizing the amino acid, L-phenylalanine, which is sourced from human diet. Many studies have observed the antimicrobial and antifungal effects of PPA. Our lab determined PPA holds antifungal activity of PPA in the gut of mice colonized with Candida albicans. We are interested in investigating how diversity in the mycobiota populations, which focuses on the fungi species in the human gut, are related to changes in PPA levels.
Therefore, this study will asses whether additional oral supplementation of L-phenylalanine has an effect on the way gut mycobiota responds to this amino acid. Healthy subjects received a 14-day supply of L-phenylalanine supplements and provided stool and blood samples to the study team.
Study design
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Healthy | Experimental | Drug: L-Phenylalanine 500 mg Veg Capsule productParticipants will receive one bottle of L-Phenylalanine 500 mg Veg Capsule product on Day 0. All subjects will be asked to start taking the supplement on Day 1 continuing until Day 14. They will be asked to take 2x 500 mg capsules in the morning and 1x 500 mg capsule in the evening daily for 14 days. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (1 listed)
- Male or female adults over the age of 18 years
Key exclusion criteria (6 listed)
- History of a diagnosis of any gastrointestinal condition, such as inflammatory bowel syndrome or disease
- Antibiotic usage within the past two weeks
- Antifungal usage within the past month
- Allergy to L-Phenylalanine or individuals with phenylketonuria (PKU)
- Adults taking medications known to interact with L-phenylalanine supplements, such as Monoamine Oxidase Inhibitors (MOAI), L-DOPA, and some antipsychotic drugs (complete and extensive drug list will be provided to interested participants during screening)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| L-Phenylalanine 500 mg Veg Capsule product500 mg Veg Capsule product | Drug | Healthy |
Primary outcome
Changes in phenylpropionic acid levels from baseline in subject fecal material
Time frame: Baseline, Week 2 (Day 14)
Metabolite phenylpropionic acid levels will be measured using mass spectrometry before (baseline) and after intervention
Change in fungal population levels, specifically gut Candida levels, from baseline in subject fecal material and swabs
Time frame: Baseline, Week 2 (Day 14)
Fungal populations, including Candida, will be measured using microbiota sequencing before (baseline) and after intervention. The most abundant fungal populations will be reported; however, the identity of those populations won't be known until sample analysis.
Change in the number of T cells that react to fungal antigens from baseline in subject blood samples
Time frame: Baseline, Week 2 (Day 14)
Blood will be processed through ELISA-based and in vitro restimulation assays to measure T cell reactivity to fungal antigens
3 secondary outcomes
Change in phenylpropionic acid levels from baseline in subject fecal material
Time frame: Baseline, Week 4 (Day 28)
Change in fungal population levels, specifically gut Candida levels, from baseline in subject fecal material
Time frame: Baseline, Week 4 (Day 28)
Change in the number of T cells that react to fungal antigens from baseline in subject blood samples
Time frame: Baseline, Week 4 (Day 28)
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 26 Jun 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Iliyan D Iliev, PhD principal investigator
Weill Medical College of Cornell University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 4 study testing L-Phenylalanine 500 mg Veg Capsule product in people with Gut Microbiome and Gut Health, run by Weill Medical College of Cornell University at 1 site in United States.
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 1 inclusion and 6 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: looking for participants now, as of the sponsor's last update on 26 Jun 2026. 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 States. 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. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
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?
Contact Emilia T Vignogna, BS (505-259-4995, etv4001@med.cornell.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Changes in phenylpropionic acid levels from baseline in subject fecal material (time frame: Baseline, Week 2 (Day 14)). The study lists 3 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 26 Jun 2026.