Spirulina, also known as Arthrospira, is a blue-green alga that gained popularity after NASA introduced it as a food supplement for astronauts on space missions. It has the ability to modulate immunological functions and has anti-inflammatory properties by preventing mast cells from releasing histamine. ^[1] 

Several studies have been conducted to determine the efficacy and potential clinical applications of Spirulina in the treatment of a variety of diseases, and a few randomized controlled trials and systematic reviews suggest that this alga may improve a variety of symptoms and may even have anticancer, antiviral, and antiallergic properties. ^[2]

Studies have shown that application of spirulina have played a role in alleviating the following symptoms:

• Allergies & Rhinitis
• Lowering Cholesterol
• Diabetes
• Cancer
• Chronic arsenic poisoning

Read more on the studies:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3136577/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2907180/