Algae Effects in Markers of Cardiovascular Risk and Gut Microbiome

NCT07173062 | Recruiting

• 1 other identifier: CALGUT
• Study Type: interventional
• Target: 150
• Locations: 1 country
• Sites: 1

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

Keywords

Spirulina Arthrospira platensis; Gelidium corneum; Trimethylamine- N-oxide (TMAO); Short-Chain Fatty Acids (SCFA); Cardiovascular risk (CVR)

Outcome Measures

Primary Outcomes (1)

• Plasma trimethylamine-N-oxide levels

  To assess the effect of the Spirulina Arthrospira platensis versus Gelidium corneum versus placebo on the between-group ratio of geometric means difference of the Log transformed plasma trimethylamine- N-oxide levels change from baseline to 20 weeks. The co-primary comparison will be Spirulina Arthrospira platensis versus Placebo and Gelidium corneum versus Placebo with a 2.5% alfa for each comparison.

  Visit 1 (day 7 to day 30) and Visit 2 (20 weeks ± 15 days from Visit 1)

Secondary Outcomes (28)

• Plasma short-chain fatty acids levels

  Visit 1 (day 7 to day 30) and Visit 2 (20 weeks ± 15 days from Visit 1)

• Gut microbiota

  Visit 1 (day 7 to day 30) and Visit 2 (20 weeks ± 15 days from Visit 1)

• Systolic blood pressure

  Visit 1 (day 7 to day 30) and Visit 2 (20 weeks ± 15 days from Visit 1)

• Diastolic blood pressure

  Visit 1 (day 7 to day 30) and Visit 2 (20 weeks ± 15 days from Visit 1)

• Body weight

  Visit 1 (day 7 to day 30) and Visit 2 (20 weeks ± 15 days from Visit 1)

Study Arms (3)

Spirulina Arthrospira platensis

EXPERIMENTAL

during 20 weeks

Dietary Supplement: Spirulina Arthrospira platensis (microalgae)

Gelidium corneum

EXPERIMENTAL

during 20 weeks

Dietary Supplement: Gelidium corneum

Placebo

PLACEBO COMPARATOR

during 20 weeks

Other: Placebo

Interventions

Spirulina Arthrospira platensis (microalgae) DIETARY_SUPPLEMENT

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

Spirulina Arthrospira platensis

Gelidium corneum DIETARY_SUPPLEMENT

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

Gelidium corneum

Placebo 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

Placebo

Eligibility Criteria

• Age: 50 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• ≥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;

You may not qualify if:

• 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.

Sponsors & Collaborators

• Universidade do Porto: lead
• Centro Hospitalar De São João, E.P.E.: collaborator

Study Sites (1)

Unidade Local de Saúde de São João

Porto, 4200-319, Portugal

RECRUITING

MeSH Terms

Conditions

Stroke; Myocardial Infarction; Diabetes Mellitus; Peripheral Arterial Disease; Renal Insufficiency, Chronic; Albuminuria

Condition Hierarchy (Ancestors)

Cerebrovascular Disorders; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Vascular Diseases; Cardiovascular Diseases; Myocardial Ischemia; Heart Diseases; Infarction; Ischemia; Pathologic Processes; Pathological Conditions, Signs and Symptoms; Necrosis; Glucose Metabolism Disorders; Metabolic Diseases; Nutritional and Metabolic Diseases; Endocrine System Diseases; Atherosclerosis; Arteriosclerosis; Arterial Occlusive Diseases; Peripheral Vascular Diseases; Renal Insufficiency; Kidney Diseases; Urologic Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Urogenital Diseases; Male Urogenital Diseases; Chronic Disease; Disease Attributes; Proteinuria; Urination Disorders; Urological Manifestations; Signs and Symptoms

Study Officials

• João Pedro Ferreira, MD, PhD

  Universidade do Porto

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Francisca Saraiva, PhD

CONTACT

220426820; f.saraiva@med.up.pt

Janete Santos, PhD

CONTACT

961239890; investigaclinica@med.up.pt

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Masking Details: double-blind masking
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: Prospective, randomized, double-blind, two-treatment, one-period, parallel trial

Study Record Dates

• First Submitted: August 12, 2025
• First Posted: September 15, 2025
• Study Start: March 11, 2025
• Primary Completion (Estimated): August 1, 2026
• Study Completion (Estimated): August 1, 2026
• Last Updated: September 15, 2025

Record last verified: 2025-09

Locations

PT (1)