Algae Effects in Markers of Cardiovascular Risk and Gut Microbiome

NCT ID: NCT07173062

Last Updated: 2025-09-15

Basic Information

• Recruitment Status: RECRUITING
• Clinical Phase: NA
• Total Enrollment: 150 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2025-03-11
• Study Completion Date: 2026-08-31

Brief Summary

The Western diet, rich in fat and sugar, contributes to cardiovascular risk and alters the body metabolism, specifically through the modulation of the microbiome. Microbiome is considered the "second genome", functioning as an endocrine-like organ. Gut microbiota-derived metabolites, namely trimethylamine- N-oxide and short-chain fatty acids have been associated with atherosclerosis, vascular and cardiac diseases. Regarding trimethylamine- N-oxide, its association with cardiovascular disease is positive and dose-dependent. In contrast, short-chain fatty acids have been positively associated with the improvement of cardiovascular health.

Algae probiotics can modulate gut microbiome, stimulating the growth of commensal micro-organisms with health benefits. Previous studies suggested that Spirulina Arthrospira platensis supplementation could improve blood lipid levels and lower blood pressure, revealing anti-inflammatory and antioxidant roles. Other probiotics that could be beneficial to gut microbiota are macroalgae or seaweed. Macroalgae are a rich source of components which may prompt bacterial diversity and abundance.

The present prospective, randomized, three-armed parallel trial aims to generate good-quality evidence about the potential health effects and impact of Spirulina Arthrospira platensis (microalgae) and Gelidium corneum (macroalgae) supplements in humans. These participants will undergo 3 clinical evaluations: 2 before the beginning of micro- and macro-algae supplementation and the last one after 20 weeks of supplementation. The evaluation includes a vascular, nutritional and physical activity assessment, as well as blood, urine, saliva and stool collection for quantification of plasma biomarkers, oral and gut microbiota analysis, respectively.

Conditions

Stroke; Coronary Arterial Disease (CAD); Myocardial Infarction (MI); Diabetes Mellitus; Peripheral Artery Disease (PAD); Chronic Kidney Disease(CKD); Albuminuria

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: PREVENTION
• Blinding Strategy: QUADRUPLE

Study Groups

Spirulina Arthrospira platensis

during 20 weeks

Group Type: EXPERIMENTAL

Spirulina Arthrospira platensis (microalgae)

Intervention Type: DIETARY_SUPPLEMENT

Spirulina Arthrospira platensis (4 x \~500mg), taken twice daily as 2 capsules in the morning + 2 capsules in the evening

Gelidium corneum

during 20 weeks

Group Type: EXPERIMENTAL

Gelidium corneum

Intervention Type: DIETARY_SUPPLEMENT

Gelidium corneum (4 x \~500mg), taken twice daily as 2 capsules in the morning + 2 capsules in the evening

Placebo

during 20 weeks

Group Type: PLACEBO_COMPARATOR

Placebo

Intervention Type: OTHER

Microcrystalline cellulose, silicon dioxide and dicalcium phosphate (4 x \~500mg), taken twice daily as 2 capsules in the morning + 2 capsules in the evening

Interventions

Spirulina Arthrospira platensis (microalgae)

Spirulina Arthrospira platensis (4 x \~500mg), taken twice daily as 2 capsules in the morning + 2 capsules in the evening

Intervention Type: DIETARY_SUPPLEMENT

Gelidium corneum

Gelidium corneum (4 x \~500mg), taken twice daily as 2 capsules in the morning + 2 capsules in the evening

Intervention Type: DIETARY_SUPPLEMENT

Placebo

Microcrystalline cellulose, silicon dioxide and dicalcium phosphate (4 x \~500mg), taken twice daily as 2 capsules in the morning + 2 capsules in the evening

Intervention Type: OTHER

Eligibility Criteria

Inclusion Criteria

• ≥50 years
• BMI ≥20 kg/m2
• History of stroke, coronary artery disease, myocardial infarction, peripheral artery disease, chronic kidney disease (eGFR <75 ml/min at least for 3 months), albuminuria >300 mg/g, or diabetes mellitus
• No antibiotics in the previous 30 days
• If a woman, she must be a woman of non-childbearing potential. That is, she must be:

• Surgically sterilized (e.g. underwent hysterectomy, bilateral salpingectomy or bilateral oophorectomy);
• Clinically diagnosed infertile;
• In a post-menopausal state, defined as no menses for 12 months without an alternative medical cause.
• A woman patient of childbearing potential must have a negative serum pregnancy test at Visit 0 (Day 0) and must agree to use consistently and correctly (from 28 days prior to first study treatment administration until at least 7 days after last study treatment administration) one of the following highly effective methods of contraception:

• Abstinence of heterosexual intercourse (when this is in line with preferred and usual lifestyle of the subject);
• Progestogen-only hormonal contraception associated with inhibition of ovulation (oral, injectable, implantable);
• Combined (oestrogen and progestogen containing) hormonal contraception associated with inhibition of ovulation (oral, intravaginal, transdermal);
• Intrauterine device;
• Intrauterine hormone-releasing system;
• Bilateral tubal occlusion;
• Vasectomized partner, who has received medical assessment of the surgical success, or clinically diagnosed infertile partner.

Exclusion Criteria

• Unwilling to sign the informed consent form (if the patient wants to participate but cannot sign for any reason, then a third-person testimony may sign/complete the informed consent form on the patient's behalf).
• Involvement in the planning and/or conduct of the study (applies to both Investigator staff and/or staff at the study site).
• Participation in another clinical study with an investigational product during the last month.

• Minimum Eligible Age: 50 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Centro Hospitalar De São João, E.P.E.

OTHER

Sponsor Role: collaborator

Universidade do Porto

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

João Pedro Ferreira, MD, PhD

Role: PRINCIPAL_INVESTIGATOR

Universidade do Porto

Locations

Unidade Local de Saúde de São João

Porto, , Portugal

Site Status: RECRUITING

Countries

Portugal

Central Contacts

Francisca Saraiva, PhD

Role: CONTACT

f.saraiva@med.up.pt

220426820 ext. +351

Janete Santos, PhD

Role: CONTACT

investigaclinica@med.up.pt

961239890 ext. +351

Facility Contacts

Francisca Saraiva, PhD

Role: primary

f.saraiva@med.up.pt

225512100 ext. +351

Other Identifiers

CALGUT

Identifier Type: -

Identifier Source: org_study_id