The effect of Spirulina sauce, as a functional food, on cardiometabolic risk factors, oxidative stress biomarkers, glycemic profile, and liver enzymes in nonalcoholic fatty liver disease patients: A randomized double-blinded clinical trial

Effects of Spirulina (Arthrospira) platensis supplementation on intestinal permeability, antioxidant and inflammatory markers, quality of life and disease severity in patients with constipated-predominant irritable bowel syndrome: a randomized double‑blind, placebo‑controlled trial

BACKGROUND

Irritable bowel syndrome (IBS) is a chronic, functional gastrointestinal disorder (FGID) which is characterized by chronic pain related to defecation and alteration in GI motility. Recent findings indicated that intestinal barrier dysfunction, hyperpermeability, oxidative stress, and inflammation play a role in IBS pathogenesis. Considering the antioxidant properties of Spirulina (Arthrospira) platensis (SP), this study aimed to investigate the effect of SP supplementation on Quality of life (QoL), disease severity, antioxidant capacity, oxidative stress index and intestinal permeability in constipation-dominant IBS (IBS-C) patients.

METHODS

This study was a parallel randomized, double-blind, placebo-controlled clinical trial involving 60 IBS-C patients aged 18-50 years. The patients were given either 1 g SP (two capsules/day; each capsule contained 500 mg of SP) or placebo for 12 weeks. IBS-QoL, IBS-Severity system score (IBS-SSS), plasma total antioxidant capacity (TAC), malondialdehyde (MDA), and zonulin levels were measured at baseline and the end of the intervention. Univariate comparison and intention-to-treat (ITT) were used for analysis.

RESULTS

SP supplementation compared to placebo resulted in a significant increase in QoL score (7.05 ± 2.02 vs. - 1.57 ± 2.49; p = 0.008), TAC (145.27 ± 30.77 vs. -54.90 ± 45.72; p < 0.001) and decrease in IBS-SSS (-32.17 ± 8.96 vs. 1.07 ± 8.49; p = 0.002), MDA level (- 11.61 ± 2.57 vs. - 2.00 ± 2.24; p < 0.001) and zonulin level (- 0.22 ± 0.05 vs. 0.12 ± 0.07; p = 0.001). These results remained significant after adjusting for baseline values.

CONCLUSIONS

SP supplementation demonstrated a promising effect in the management of IBS. However, larger trials with a dose-dependent approach in IBS-C and other subtypes of IBS are warranted.

TRIAL REGISTRATION

The study protocol was approved by the ethical committee at the Isfahan University of Medical Sciences (Registration No. IR.MUI.

RESEARCH

REC.1401.370) and registered online at http://www.IRCT.ir (code: IRCT20140208016529N8, approved date 25.04.2023).

Impact of Spirulina Supplementation on Obesity, Hypertension, Hyperglycemia, and Hyperlipidemia: A Systematic Review

Aims: This systematic review evaluates how Spirulina supplementation impacts human metabolic syndrome. This review encompasses a broad spectrum of Spirulina supplementation studies, including variations in dosage, trial duration, participants, and the subsequent effects on human metabolic syndrome. Methods: The method involves searching for articles from the Scopus and PubMed databases (up to 2023) to identify relevant studies on Spirulina supplementation. The journal database related to the study was examined using the systematic review approach. Results: Out of 527 articles related to Spirulina supplementation, 13 articles were determined to be suitable for human clinical studies. The treatment is performed at 20 mg to 6 g within 17-360 days. Spirulina contains macro- and micronutrients, vitamins, and minerals that are beneficial for health, as well as several bioactives that play a role in improving metabolic syndrome. This seaweed pigment can reduce obesity, body mass index (BMI), hypertension, hyperglycemia, and dyslipidemia. Its tripeptides lower blood pressure while gamma linoleic acid and glycolipids improve lipid profile. The findings show that Spirulina supplementation improves human metabolic syndrome. It included obesity, hypertension, hyperglycemia, and hyperlipidemia. Conclusion: Spirulina supplementation in humans has a positive effect on metabolic syndrome. It is due to phycocyanin, L-isoleucyl-L-glutaminyl-L-proline (Ile-Gln-Pro), gamma-linolenic acid, and the glycolipid H-b2. However, the form of use, dosage, and treatment should be further researched to determine the right amount for each metabolic syndrome problem.

The Effect of Algae Supplementation on Anthropometric Indices in Adults: A GRADE-Assessed Systematic Review and Meta-Analysis of Randomized Controlled Trials

CONTEXT

Inconsistent results have been reported regarding the effects of different types of algae, such as Spirulina and Chlorella, on anthropometric indices.

OBJECTIVE

To conduct a meta-analysis to assess the efficacy of algae supplementation on anthropometric indices.

DATA SOURCES

A comprehensive systematic search was conducted to find relevant articles published from January 1990 to January 2024.

DATA EXTRACTION

Randomized controlled trials (RCTs) comparing algae supplementation with a placebo or control group were included. The risk of bias and certainty of the evidence were evaluated using the Cochrane risk-of-bias tool and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology, respectively. The random-effects model was used to find the Weighted mean differences (WMDs) for each outcome.

DATA ANALYSIS

Of 9079 distinct articles in the initial screening, 61 clinical trials were included in this meta-analysis. Algae supplementation resulted in lower body mass index (WMD, -0.27 kg/m2 (95% CI, -0.42 to -0.13); GRADE rating, low), body weight (WMD: -0.78 kg [-1.18 to -0.38]; GRADE rating, low), waist circumference (WMD, -0.68 cm [-1.27 to -0.10]; GRADE rating, very low), kilograms of body fat (WMD, -0.65 kg [-1.13 to -0.17]; GRADE rating, low), and body fat percentage (WMD, -0.9% [-1.62 to -0.17]; GRADE rating, very low) compared with placebo or controls. Nevertheless, the statistically significant effects of algae supplementation on hip circumference (WMD, -0.20 cm [-0.73 to 0.32]; GRADE rating, moderate), waist to hip ratio (WMD, -0.01 [-0.01 to 0.00]; GRADE rating, moderate), and lean body mass (WMD, -0.30 kg [-0.62 to 0.02]; GRADE rating, moderate) were not observed.

CONCLUSIONS

Overall, the findings of this meta-analysis indicate supplementation with algae may exert beneficial effects on anthropometric indices. However, due to between-studies heterogeneity and very low to low levels of GRADE for significant outcomes, the results should be interpreted with caution.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42024522923.

The Effect of Spirulina Supplementation on Blood Pressure in Adults: A GRADE-Assessed Systematic Review and Meta-Analysis of Randomized Clinical Trials

Previous studies have yielded controversial results regarding the effect of spirulina on blood pressure (BP), which need updating. So, this updated systematic review and meta-analysis of randomized controlled trials (RCTs) carry out a more accurate estimation of the effect of spirulina on BP in adults. This systematic searches (in PubMed/Medline, Scopus, and ISI Web of Science) until April 1, 2024, to identify related RCTs based on PICOS guidelines (population (individuals > 18 years old), the intervention (spirulina), the comparison (control or placebo group), the outcomes (systolic BP (SBP) and diastolic BP (DBP)), the study design (RCTs)), and PRISMA-checklist (Supporting Information, data S2). We evaluated the impact of spirulina on DBP and SBP. Conventional procedures were employed for analyzing publication bias, heterogeneity, and sensitivity. The GRADE criteria and the Cochrane assessment method were employed to evaluate the risk of bias (ROB) and certainty of evidence across the studies, respectively. The result shows spirulina consumption decreases SBP (WMD: -4.41 mmHg, 95% CI: -6.74 to -2.07, I 2 = 66.1%) and DBP (WMD: -2.84 mmHg, 95% CI: -4.65 to -1.03, I 2 = 62.3%). Subgroup analysis demonstrated SBP and DBP were still lower in individuals with ≥ 120 and ≥ 80 mmHg, hypertension (HTN) individuals, overweight individuals, age > 50 years, and > 8 weeks of intervention. Indeed, we do not observe publication bias, ROB, or interference studies in the overall results of BPs, and based on GRADE, our outcomes have moderate quality. Because of the low number of studies and participants, the dose-response and meta-regression are not significant. His study demonstrated spirulina intervention decreased SBP and DBP in HTN and overweight individuals, age > 50 years, and > 8 weeks of intervention. So, spirulina intake decreases BP and could be used in clinical practice. Furthermore, more and high-quality RCTs are needed to establish the clinical efficacy of the spirulina and determine cutoff spirulina interventions based on dose and duration. Trial Registration: PROSPERO: CRD42024534608.

Comprehensive Review of the Latest Investigations of the Health-Enhancing Effects of Selected Properties of Arthrospira and Spirulina Microalgae on Skin

Arthospira platensis and Spirulina platensis microalgae are a rich source of pro-health metabolites (% d.m.): proteins (50.0-71.3/46.0-63.0), carbohydrates (16.0-20.0/12.0-17.0), fats (0.9-14.2/6.4-14.3), polyphenolic compounds and phenols (7.3-33.2/7.8-44.5 and 4.2/0.3 mg GAE/g), and flavonoids (1.9/0.2 QUE/g) used in pharmaceutical and cosmetic formulations. This review summarises the research on the chemical profile, therapeutic effects in dermatological problems, application of Arthrospira and Spirulina microalgae, and contraindications to their use. The pro-health properties of these microalgae were analysed based on the relevant literature from 2019 to 2024. The antiviral mechanism of microalgal activity involves the inhibition of viral replication and enhancement of immunity. The anti-acne activity is attributed to alkaloids, alkanes, phenols, alkenes, phycocyanins, phthalates, tannins, carboxylic and phthalic acids, saponins, and steroids. The antibacterial activity generally depends on the components and structure of the bacterial cell wall. Their healing effect results from the inhibition of inflammatory and apoptotic processes, reduction of pro-inflammatory cytokines, stimulation of angiogenesis, and proliferation of fibroblasts and keratinocytes. The photoprotective action is regulated by amino acids, phlorotannins, carotenoids, mycosporins, and polyphenols inhibiting the production of tyrosinase, pro-inflammatory cytokines, and free oxygen radicals in fibroblasts and the stimulation of collagen production. Microalgae are promising molecular ingredients in innovative formulations of parapharmaceuticals and cosmetics used in the prophylaxis and therapy of dermatological problems. This review shows the application of spirulina-based commercial skin-care products as well as the safety and contraindications of spirulina use. Furthermore, the main directions for future studies of the pro-health suitability of microalgae exerting multidirectional effects on human skin are presented.

Enhancing Laying Hens' Performance, Egg Quality, Shelf Life during Storage, and Blood Biochemistry with Spirulina platensis Supplementation

Enhancing the sustainability of chicken farming involves improving health and productivity and product qualities. This study explores the influence of Spirulina platensis (SP) supplementation on the productivity, egg quality, shelf life during storage, and blood biochemistry of laying hens. A total of 192 thirty-nine-week-old White Leghorn hens were randomly divided into 4 dietary groups: a control group and 3 treatment groups receiving 2.5 g/kg, 5 g/kg, or 10 g/kg of SP, respectively. The study was conducted for six weeks with measuring feed intake, feed conversion ratio, egg production, egg quality, shelf life, and blood biochemistry. The results demonstrated significant enhancements in egg weight (p < 0.05) and egg mass (p < 0.05) in the treatment of SP groups. The SP treated hens showed significant improvements in yolk color (p < 0.05) and Haugh unit scores (p < 0.05). The SP supplementation showed a hepatoprotective effect, as indicated by significant reduction in Alanine aminotransferase (ALT) (p < 0.05) and alkaline phosphatase (ALP) (p < 0.05) levels; however, increases in total protein, albumin, and globulin levels were observed. Furthermore, the egg quality of stored eggs for 21 days linearly increased with increments in the SP levels. In conclusion, it can be speculated that adding SP at 2.5 g/kg and 5 g/kg can significantly improve the productivity of laying hens, eggs' quality, shelf life, and blood biochemistry, thereby contributing to a more sustainable and efficient chicken production.

Natural Products as Hepatoprotective Agents-A Comprehensive Review of Clinical Trials

The hepatoprotective effects of natural products have been a significant focus in recent decades due to the growing demand for the help in the treatment of hepatic impairments. This review specifically delves into the findings of clinical trials involving 13 selected natural products, namely plants and their derived compounds (e.g., artichoke, berberine, and turmeric), algae (e.g., spirulina), probiotics, and other products like phospholipids and vitamin D. A literature search was performed in the Scopus database, PubMed, and Google Scholar, covering all articles found up to June 2024. Artichoke, berberine, chlorella, chicory, green tea, probiotics, phospholipids, schisandra, silymarin, spirulina, and vitamin D caused a decrease in liver enzymes, while for cinnamon and turmeric such an effect was either not observed or not convincing. The presented results indicate that some natural products might satisfactorily improve hepatic outcomes in NAFLD, NASH, and other liver disorders; however, further studies and metanalyses are needed to clearly demonstrate their effectiveness.

Spirulina (Arthrospira platensis) Improved Nonalcoholic Fatty Liver Disease Characteristics and Microbiota and Did Not Affect Organ Fibrosis Induced by a Fructose-Enriched Diet in Wistar Male Rats

Spirulina (Arthrospira platensis) is reported to play a role in improving nonalcoholic fatty liver disease (NAFLD) and intestinal microbiota (IM). To study spirulina's effects in the improvement of NAFLD characteristics, IM, and pancreatic-renal lesions induced by a fructose-enriched diet, 40 Wistar healthy male rats, weighing 200-250 g, were randomly divided into four groups of 10, and each rat per group was assigned a diet of equal quantities (20 g/day) for 18 weeks. The first control group (CT) was fed a standardized diet, the second group received a 40% fructose-enriched diet (HFr), and the third (HFr-S5) and fourth groups (HFr-S10) were assigned the same diet composition as the second group but enriched with 5% and 10% spirulina, respectively. At week 18, the HFr-S10 group maintained its level of serum triglycerides and had the lowest liver fat between the groups. At the phylae and family level, and for the same period, the HFr-S10 group had the lowest increase in the Firmicutes/Bacteroidetes ratio and the Ruminococcaceae and the highest fecal alpha diversity compared to all other groups (p < 0.05). These findings suggest that at a 10% concentration, spirulina could be used in nutritional intervention to improve IM, fatty liver, metabolic, and inflammatory parameters associated with NAFLD.

Beneficial Effects of Spirulina Supplementation in the Management of Cardiovascular Diseases

In recent decades, as a result of rising mortality rates due to cardiovascular diseases (CVDs), there has been a growing urgency to find alternative approaches to conventional pharmaceutical treatment to prevent the onset of chronic diseases. Arthrospira platensis, commonly known as Spirulina, is a blue-green cyanobacterium, classified as a "superfood", used worldwide as a nutraceutical food supplement due to its remarkable nutritional value, lack of toxicity, and therapeutic effects. Several scientific studies have evaluated the cardioprotective role of Spirulina. This article presents a comprehensive review of the therapeutic benefits of Spirulina in improving cardio- and cerebrovascular health. It focuses on the latest experimental and clinical findings to evaluate its antihypertensive, antidiabetic, and antihyperlipidemic properties. The objective is to highlight its potential in preventing and managing risk factors associated with cardiovascular disease (CVD).

The effect of spirulina sauce on glycemic index, lipid profile, and oxidative stress in type 2 diabetic patients: A randomized double-blind clinical trial

We aimed to evaluate the effect of spirulina sauce on glycemic indices, lipid profile, oxidative stress markers, and anthropometric measurement in type 2 diabetic patients. Forty patients were randomly assigned to receive 20 g/day spirulina sauce (containing 2 g of spirulina) or placebo for 2 months. Anthropometric and biochemical indices were measured at the beginning and end of the intervention. Fasting blood glucose (mean difference (MD): -15.3 mg/dL, 95% confidence (CI): -44.2 to 13.60, p = .26), HbA1c (MD: 0.13%, 95% CI: -0.83 to 0.57, p = .75), insulin (MD: -1.46 μIU/mL, 95% CI: -4.0 to 1.09, p = .28), and HOMA-IR (MD: -0.35, 95% CI: -2.0 to 1.32, p = .68) did not change significantly between groups. QUICKI increased significantly (MD: 0.025, 95% CI: 0.006 to 0.045, p = .03). Among the lipid profile, triglyceride (TG) (MD: -68.6 mg/dL, 95% CI: -107.21 to -29.98, p < .001), total cholesterol (MD: -29.55 mg/dL, 95% CI: -55.28 to -3.81, p = .02), and LDL (MD: -17.7 mg/dL, 95% CI: -33.24 to -2.15, p = .01) were significantly decreased in the spirulina group compared to the control; whereas, the change in HDL was non-significant. No significant change was observed in body composition and anthropometric measurements, except waist circumference, which was reduced (MD: -2.65 cm, 95% CI: -3.91 to -1.38, p = .001). Hunger index significantly decreased and fullness increased marginally significantly. Although malondialdehyde was significantly reduced, no change was observed in total antioxidant capacity (TAC). Spirulina sauce was not effective for glycemic control in type 2 diabetes; however, could be useful for controlling appetite and ameliorating lipid profile.

Effect of a novel dietary supplement Khejri, and Spirulina supplementation on lipid profile in cricket players

Prosopis cineraria (Fabaceae) is known as Khejri in India or the golden tree of Indian deserts. It's potential as a dietary supplement in sports nutrition and its effect on regulating lipid profile has never been investigated. Spirulina (Arthrospira platensis) is a superfood with high nutritional value and is a popular supplement among athletes. In the current study, Spirulina and Khejri were used as supplements by cricket players to improve their physical fitness and lipid profile. Both supplements were given to individual groups and in combination to see the combined effect. The intervention period was 21 days, and supplements were given in 500 mg doses daily. Lipid profile assessments were done before and after the intervention period. 40 cricket players were divided into 4 groups: Group 1 (n = 10): Both supplements, Spirulina and Khejri, Group 2 (n = 10): Supplement Spirulina, Group 3 (n = 10): Supplement Khejri, and Group 4 (n = 10): Control. When experimental groups 1, 2 and 3 were compared to the control group 4, significant reduction was observed in triglyceride levels (Group1 vs. control: 141.53 ± 14.74 vs. 199.28 ± 27.24, p < 0.05; Group 2 vs. control: 137.5 ± 14 vs. 199.28 ± 27.24, p < 0.05; Group 3 vs. control: 135.32 ± 17.34 vs. 199.28 ± 27.24, p < 0.05) and significant reduction in cholesterol levels was found post-intervention after 21 days of supplementation (Group1 vs. control: 149.75 ± 7.08 vs. 207.86 ± 11.69, p < 0.001; Group 2 vs. control: 178.28 ± 9.43 vs. 207.86 ± 11.69, p < 0.05; Group 3 vs. control: 142.92 ± 10.01 vs. 207.86 ± 11.69, p < 0.001). Cholesterol and Triglyceride levels were significantly decreased pre- vs. post-intervention by Khejri and Spirulina supplements in cricket players.

Short-Term Effects of Spirulina Consumption on Glycemic Responses and Blood Pressure in Healthy Young Adults: Results from Two Randomized Clinical Trials

The effects of spirulina consumption added in foods were investigated in two crossover clinical trials (n = 13 different healthy adults). In Trial-1 adults consumed cookies with-and-without spirulina (3.12 g per 100 g final product; 2.5 g spirulina per 50 g available carbohydrates) according to glycemic index (GI) methodology. In Trial-2, adults consumed 4 g, 6 g, and 8 g spirulina as beverage diluted in 50 g D-glucose vs. 50 g plain D-glucose. Capillary blood glucose samples were collected at 0, 15, 30, 45, 60, 90, and 120 min and blood pressure (BP) was measured at beginning and end of each visit in both trials. Trial-1: both cookies with and without spirulina provided medium GI values (59 and 60, respectively, on glucose-scale), but no significant differences were found for BP. Trial-2: both 4 g and 8 g spirulina lowered postprandial glucose at 120 min (95% CI: -1.64 to -16.12 and -1.23 to -15.87, respectively). The results explained 29% of variation. Only 8 g spirulina decreased significantly 90-120 min area under the curve (AUC) for glucose and systolic BP (-4%). No differences were found for fasting glucose. Adding spirulina to cookies did not affect glucose responses and BP. Only 8 g provided significantly lower 90-120 min-AUC for glucose and BP compared to 4 g, 6 g-and-D-glucose, indicating advantages to glycemic control and hypertension.

Antioxidant Efficacy of a Spirulina Liquid Extract on Oxidative Stress Status and Metabolic Disturbances in Subjects with Metabolic Syndrome

Lipid peroxidation is associated with the development of some pathologies, such as cardiovascular diseases. Reduction in oxidative stress by antioxidants, such as Arthrospira (formely Spirulina), helps improving this redox imbalance. The aim of the study was to evaluate the effect of the Arthrospira liquid extract “Spirulysat^®” on oxidative markers—in particular, oxidized LDL (oxLDL)/total LDL cholesterol—and isoprostanes and to investigate its impact on lipid and glucose metabolism in the metabolic syndrome subject. A controlled, randomised, double-blind design was conducted in 40 subjects aged 18 to 65 years with metabolic syndrome after a daily intake of Spirulysat^® or placebo for twelve weeks. Blood and urinary samples were collected at three visits (V1, V2, V3) in the two groups for parameters determination. Although the Spirulysat^® group showed a decrease at all visits of the oxLDL/total cholesterol ratio, there was no significant difference compared to the placebo (p = 0.36). The urinary isoprostanes concentration in the Spirulysat^® group was reduced (p = 0.014) at V3. Plasma triglycerides decreased at V3 (p = 0.003) and HDL-cholesterol increased (p = 0.031) at all visits with Spirulysat^®. In conclusion, Spirulysat^® did not change the oxidized LDL (oxLDL)/LDL ratio but decreased the urinary isoprostanes, plasma triglycerides and increased HDL cholesterol, suggesting a beneficial effect on metabolic syndrome.

Alternative protein sources of plant, algal, fungal and insect origins for dietary diversification in search of nutrition and health

This review aimed to compare alternative protein sources in terms of nutritional composition and health benefits with the purpose of disseminating up-to-date knowledge and contribute for diversification of the food marked and consumers decision-making. Plant-based is the most well-established category of alternative proteins, but there is still room for diversification. Less conventional species such as chia seeds are prominent sources of ω-3 (∼60% total lipids), while hempseed and quinoa are notable sources of ω-6 (up to 58% and 61%, respectively). Edible insects and microalgae are alternative foods rich in protein (up to 70%), fibers (∼30%), as well as peptides and polysaccharides with antimicrobial, antioxidant, anti-hypertensive, antidiabetic, antidepressant, antitumor, and immunomodulatory activities. Additionally, lipid contents in insect larvae can be as high as 50%, on a dry weight basis, containing fatty acids with anti-inflammatory and antitumor properties. In contrast, edible fungi have low lipid contents (∼2%), but are rich in carbohydrates (up to 79%) and have balanced amino acid profiles. The results suggest that food formulations combining different alternative protein sources can meet dietary requirements. Further studies on flavoring and texturing processes will help to create meat and dairy analogs, thus helping to broaden acceptance and applicability of alternative protein sources.