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Gastrointestinal ProblemTetrasolNCT06425094

Effects of a Microalgae Extract Dietary Supplement on Gut Health, Anxiety, and Immune Function

A study testing Microalgae Extract Capsules in people with Gastrointestinal Problem and Anxiety, run by Colorado State University at 1 site in United States.

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

This study will be conducted to determine the effect of daily Tetrasol consumption in supporting gut health using assessments of gastrointestinal symptoms (GSRS) and bowel habits (BSS) as primary outcome measures. Read more about this study

Who is it for?
Ages 18 to 55 yearsHealthy volunteers can take part
Conditions the study is for
Gastrointestinal Problem, Anxiety, Stress
What is being tested?
Microalgae Extract Capsules
Type of treatment
Pill or oral medicine
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
62 participants
Where
1 siteUnited States
Study dates
5 Feb 2024to 31 Jan 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 55 years
  • All sexes
  • Healthy volunteers accepted
  • Adult

Who may be able to join

  • Healthy, normal to overweight (BMI of 18.0-29.9) adults between 18-55 years of age with mild to moderate gastrointestinal distress confirmed by one positive response to the Rome IV criteria (Appended).

Who cannot join

  • BMI >30.0 or <18.0
  • Smoking or other use of tobacco products
  • Diagnosed intestinal diseases such as Celiac, Crohn's Disease, Ulcerative Colitis, or Gastrointestinal Cancers
  • Pregnant or breastfeeding individuals
  • Regular use of NSAIDs or MAO inhibitors
  • Clinically diagnosed mental health disorders (clinical depression, bipolar disorder, etc.)

Trial locations and contacts

1 site in 1 country.

United States1 site
  • Food and Nutrition Clinical Research Lab(FNCRL), Colorado State University

    Fort Collins, Colorado, 80526

Other trials in United States

About this study

This study will be conducted to determine the effect of daily Tetrasol consumption in supporting gut health using assessments of gastrointestinal symptoms (GSRS) and bowel habits (BSS) as primary outcome measures. The investigators also intend to explore fecal and blood biomarkers of intestinal permeability/function, determination of anxiety and stress levels through both validated assessments and saliva and blood biomarkers, establishment of intervention safety and tolerability through comprehensive metabolic panels and overall compliance, explore the effects of the intervention on inflammation and acute stress (Cold Presser Test), blood lipid profiles, and gut microbiota composition as secondary outcomes.

Read the detailed description
  1. Total number of subjects who will be approached (including screen fails, controls, and subject withdrawals) to reach enrollment numbers for the lifetime of the study for this investigator's site: 100-125
  2. Total number of subjects to be enrolled at this site: The investigators plan to enroll 60 participants for a target completion of 50 participants (25/arm). Enrolling 60 individuals allows for a conservative 20% attrition rate. This is the first human study of the commercial product Tetrasol, which looks at intestinal health outcomes. Therefore, this will be considered a pilot study, and the data will allow us to determine the appropriate sample size for a statistically powered study to identify differences in gastrointestinal health between Tetrasol consumers and placebo.
  3. Brief Description/justification for the proposed sample size in lay terms: The investigators have no human data related to our primary outcome measures for this product. Therefore, investigators propose a pilot study of 25 individuals in each study group.
  4. Before the start of enrollment, 60 subjects will be randomly assigned using a random number generator. Upon enrollment, each subject will be assigned either intervention A or B, according to the randomization chart.
  5. The study will be a double-blind, placebo-controlled study. Neither the investigators nor the participants will have knowledge of the contents of the capsules. The capsules will be labeled by Microphyt personnel who are not directly involved in the study, and they will maintain the code. Unlike the intervention capsules, the placebo does not contain rapeseed oil and calcium, as the product manufacturer developed these formulations. They wished to keep the placebo formula the same as the formula previously used in their in vitro assays and other clinical work for more equitable comparisons across studies. CSU clinical personnel will administer the two intervention capsules to the subjects according to the randomization strategy and will not be provided with the code for intervention groups until after all data analysis has been completed. In a very unlikely case of a severe adverse event (which is an event that requires the subject's hospitalization), the medical personnel will be provided information about the content of the capsules taken by the participant directly by the Microphyt personnel. The code will not be broken to the investigators until after all data has been analyzed and submitted as a preliminary report.
  6. Recruitment:

Recruitment advertisements will be placed in the Coloradoan and other newspapers/newsletters as relevant and will be sent out electronically through the CSU faculty and administrative professionals list on the CSU State Classified list. The investigators will reach out to graduate students and undergraduates by sending the recruitment email to the appropriate administrative personnel in each department (i.e., Grad coordinators and academic success coordinators) and have them forward the study information to their students. Flyers will be posted and distributed throughout the CSU campus and at targeted locations within the community, including UC Health doctor's offices. Flyers will be sent out as direct mailers to individuals in the community; their names and addresses will be purchased from a reputable company that provides names and addresses of individuals in this age range (Alesco Data, http://www.alescodata.com/). To increase participant diversity, investigators will also reach out to student groups on campus, including the Adult Learner and Veterans Services, Asian Pacific American Cultural Center, Black/African American Cultural Center, El Centro, Native American Cultural Center, Pride Resource Center, and Women and Gender Advocacy Center, and cultural groups off campus such as the BIPOC Alliance. Finally, investigators will also contact individuals in our clinical database who participated in previous studies and indicated a willingness to be contacted for future studies.

  1. Screening Procedures or Interview/questionnaire: After a preliminary telephone screening (questionnaire attached), volunteers will undergo an in-person screening (visit 1) and provide written informed consent. A questionnaire will assess medical and health history and demographic information, followed by an anthropometric assessment (height, weight, waist, and hip circumferences).
  2. Informed consent process and timing of obtaining consent. Potential participants determined to be eligible through telephone screening will be emailed a copy of the consent form and asked to read it before their screening visit. At the screening visit, the study coordinator or other study personnel will review the consent form and encourage the participants to ask any questions about participation in the study. Study personnel conducting the consenting process will assess the ability of the individual to provide informed consent. They will also ensure that all participants know that consent can be withdrawn anytime.

On the first visit (Screening, visit 1), after the participant receives a verbal and written explanation of the project and after the participant provides informed consent, investigators will assess the participant's medical and health history and dietary intake. The investigators will measure the participant's height, weight, and waist and hip circumferences. If the participant qualifies for our study, the participant will be scheduled for the second visit (Baseline, Visit 2). The participant will be provided food diaries and instructed to record all dietary and beverage intake for 2 weekdays and one weekend day before the next study visit. The participant will also be given a worksheet to record the participant's daily bowel movements and a stool collection kit for fecal collection prior to the next study visit. During the second visit (Baseline Visit, visit 2), following an overnight fast, investigators will collect stool samples and bowel movement worksheets, and the participant's body weight, waist, and hip circumferences will be measured. The participant will participate in the cold pressor test, which involves immersing the participant's hand in ice water for 2 and a half minutes while the participant's blood pressure is assessed. The investigators will provide the participants with daily dosing/treatment records and diet records, and the participants will complete sleep, physical activity, gastrointestinal, and mental health questionnaires. The investigators will perform a blood draw and collect the participant's saliva. The participant will then be scheduled for the participant's next appointment and given a 2-week supply of the participant's randomly assigned treatment capsules. This is a double-blind study, meaning neither the participant nor the investigators will know which treatment the participant has been assigned to take. The participant will be provided food diaries and instructed to record all dietary and beverage intake for 2 weekdays and one weekend day before the next study visit. The participant will also be given a worksheet to record the participant's daily bowel movements and a stool collection kit for fecal collection before the next study visit. The participant will also be provided with monetary compensation. During the participant's third visit (Midpoint Visit, Visit/Week 2), following an overnight fast, investigators will collect stool samples and bowel movement worksheets, and the participant's body weight, waist and hip circumferences, supine blood pressure, and heart rate will be measured. The investigators will check the participant's daily dosing/treatment records and diet records and perform a physical activity questionnaire. The investigators will perform a blood draw and collect the participant's saliva. The investigators will review the participant's gastrointestinal and mental health questionnaires. The participant will then be scheduled for the participant's next appointment and given the participant's final allocation of the participant's assigned treatment capsules. The participant will be provided food diaries and instructed to record all dietary and beverage intake for 2 weekdays and one weekend day before the final study visit. The participant will also be given a worksheet to record the participant's daily bowel movements and a stool collection kit for fecal collection before the next study visit. The participant will also be provided with monetary compensation. During the participant's fourth visit (Final Visit, visit 4, Week 4), following an overnight fast, investigators will collect stool samples and bowel movement worksheets, and the participant's body weight, waist, and hip circumferences will be measured. The investigators will check the participant's daily dosing/treatment records and diet records and perform a physical activity questionnaire. The investigators will perform a blood draw and collect the participant's saliva. The participant will also be subjected to an acute stress test, during which the participant will alternate between placing the participant's hand in ice-cold water for 2 and a half minutes while the participant's blood pressure is assessed. This additional test is non-invasive, and the entire test (with an included instructional period) will last approximately 30 minutes. The investigators will review the participant's gastrointestinal and mental health questionnaires. The participant will be provided with monetary compensation and will have completed the study.

Being tested
Microalgae Extract Capsules, Placebo
Keywords
Tetrasol, Gastrointestinal Symptoms, Anxiety, Stress, Gastrointestinal Problem, Bowel Habits
Medical subject headings
Anxiety Disorders

What participants receive

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

  • Microalgae Extract CapsulesDietary supplement

    Tetrasol extract

  • PlaceboDietary supplement

    maltodextrin \& vegetable magnesium stearate

Study groups in NCT06425094
Study groupRoleWhat they receive
Microalgae extract capsulesExperimentalTetrasol extract, maltodextrin, vegetable magnesium stearate, dicalcium phosphate, hydrogenated rapeseed oil, hydroxypropylmethylcellulose
Receives: Dietary Supplement: Microalgae Extract Capsules
PlaceboPlacebo comparatormaltodextrin, vegetable magnesium stearate
Receives: Dietary Supplement: Placebo

What is being measured

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

  1. Deviations from Standard Blood Chemistry as an indicator of safety

    Product safety will be assessed using the Piccolo Xpress Comprehensive Metabolic Panel that is conducted on samples collected at visit 2 (baseline), visit 3 (Week 2) \& visit 4 (Week 4) for deviations from standard reference ranges for analytes in this panel.

    Measured: 4 Weeks

  2. Gastrointestinal symptoms (GSRS)

    Gastrointestinal symptoms will be reported using the Gastrointestinal Symptom Rating Score (GSRS) at visit 2(baseline), visit 3 (Week 2) \& visit 4 (Week 4).

    Measured: 4 weeks

Secondary outcomes (7)
  1. Bowel movement regularity

    Regularity of bowel movements will be assessed throughout the study by daily completion of a Bristol Stool Chart.

    Measured: 4 Weeks

  2. Gut microbiota composition

    Gut microbiota composition will be analyzed by 16s rRNA sequencing using fecal samples collected on visit 2 (baseline), visit 3 (week 2) \& visit 4 (week 4).

    Measured: 4 Weeks

  3. Short Chain Fatty Acid quantification in feces

    Short chain fatty acids will be measured by GC-FID at visits 2 (baseline), visit 3 (Week 2), and visit 4 (Week 4).

    Measured: 4 Weeks

  4. Hemodynamics during acute stress

    Hemodynamics will be measured during a Cold Pressor Test (CPT) at visit 2 (baseline) and visit 4 (Week 4)

    Measured: 4 Weeks

  5. Anxiety levels determined by GAD-7 self-assessments.

    Participants will complete the Generalized Anxiety Disorder 7-item (GAD-7) tool on visit 2 (baseline), visit 3 (Week 2) \& visit 4 (Week 4).

    Measured: 4 Weeks

  6. Affect scores

    Participants will complete the Positive and Negative Affect Score (PANAS) tool on visit 2 (baseline), visit 3 (Week 2) \& visit 4 (Week 4).

    Measured: 4 weeks

  7. Perceived Chronic Stress

    Participants will complete the Perceived Stress Scale (PSS) tool on visit 2 (baseline), visit 3 (Week 2) \& visit 4 (Week 4).

    Measured: 4 weeks

Timeline

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

  1. First posted22 May 2024
  2. Study start5 Feb 2024
  3. Primary completion24 May 2024
  4. Study completion31 Jan 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
Prevention
Allocation
Randomised
Intervention model
Parallel groups
Model description
Randomized, parallel arm, double-blind, placebo-controlled diet intervention
Masking
Triple blind
Who is masked
Participant, Investigator, Outcomes assessor
Enrolment
62 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT06425094
Sponsor's protocol ID
5162
Acronym
Tetrasol
Status last verified
Feb 2026
First submitted
13 May 2024
Last updated
17 Feb 2026
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Publications

  • Merchant RE, Andre CA. A review of recent clinical trials of the nutritional supplement Chlorella pyrenoidosa in the treatment of fibromyalgia, hypertension, and ulcerative colitis. Altern Ther Health Med. 2001 May-Jun;7(3):79-91.

    PubMed 11347287
  • Avila-Roman J, Talero E, Alcaide A, Reyes Cde L, Zubia E, Garcia-Maurino S, Motilva V. Preventive effect of the microalga Chlamydomonas debaryana on the acute phase of experimental colitis in rats. Br J Nutr. 2014 Oct 14;112(7):1055-64. doi: 10.1017/S0007114514001895. Epub 2014 Sep 5.

    PubMed 25192306
  • Avila-Roman J, Talero E, Rodriguez-Luna A, Garcia-Maurino S, Motilva V. Anti-inflammatory effects of an oxylipin-containing lyophilised biomass from a microalga in a murine recurrent colitis model. Br J Nutr. 2016 Dec;116(12):2044-2052. doi: 10.1017/S0007114516004189. Epub 2016 Dec 27.

    PubMed 28025954
  • Maltz S, Nacey AT, Maury J, Ghanem N, Lee SY, Aquilino TM, Graham EL, Wrigley SD, Whittington JM, Khandaker AM, Hart RA, Byrne L, Wei Y, Pradelles R, Johnson SA, Weir TL. Effects of Supplementation with Microalgae Extract from Tetradesmus obliquus Strain Mi175.B1.a on Gastrointestinal Symptoms and Mental Health in Healthy Adults: A Pilot Randomized, Double-Blind, Placebo-Controlled, Parallel-Arm Trial. Nutrients. 2025 Mar 10;17(6):960. doi: 10.3390/nu17060960.

    PubMed 40289936

Questions about this trial

What is this clinical trial studying?

A study testing Microalgae Extract Capsules in people with Gastrointestinal Problem and Anxiety, run by Colorado State 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: finished, as of the sponsor's last update on 17 Feb 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. 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?

Deviations from Standard Blood Chemistry as an indicator of safety (time frame: 4 Weeks). 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?

On the ClinicalTrials.gov record for NCT06425094, which also lists 4 linked publications.

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 17 Feb 2026.

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