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.
≥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
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.
In participants recruited at Unidade Local de Saúde de São João, the exclusion criteria applied is estimated Glomerular Filtration Rate (eGFR) <30 ml/min/1.73m2 estimated with the CKD-EPI (2021) formula or dialysis. For participants recruited at community, this exclusion criteria is adapted for diagnosis of end-stage renal disease or dialysis (no need to quantify the eGFR).
Parallel
Spirulina Arthrospira platensis (microalgae)
Dietary supplementSpirulina Arthrospira platensis (4 x \~500mg), taken twice daily as 2 capsules in the morning + 2 capsules in the evening
Gelidium corneum
Dietary supplementGelidium corneum (4 x \~500mg), taken twice daily as 2 capsules in the morning + 2 capsules in the evening
Placebo
Other interventionMicrocrystalline cellulose, silicon dioxide and dicalcium phosphate (4 x \~500mg), taken twice daily as 2 capsules in the morning + 2 capsules in the evening
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.
Plasma short-chain fatty acids levels
To assess the effect of the Spirulina Arthrospira platensis versus Gelidium corneum versus placebo on the percentage change of the following measures relative to the baseline measures.
Gut microbiota
To assess the effect of the Spirulina Arthospira platensis versus Gelidium corneum versus placebo on the percentage change of the following measures relative to the baseline measures.
Systolic blood pressure
To assess the effect of the Spirulina Arthrospira platensis versus Gelidium corneum versus placebo on the percentage change of the following measures relative to the baseline measures.
Diastolic blood pressure
To assess the effect of the Spirulina Arthrospira platensis versus Gelidium corneum versus placebo on the percentage change of the following measures relative to the baseline measures.
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Universidade do Porto
Lead sponsor
Centro Hospitalar De São João, E.P.E.
Collaborator
