**5.** *Chlorella* **as a feed supplement for humans**

Microalgae are effective producers of high-protein biomass due to their quick growth rates and use of renewable resources. Microalgae are photosynthetic heterotrophic organisms that include vital amino acids, protein, minerals, vitamins, chlorophylls, antioxidants, and bioactive compounds [64]. Microalgae have been used in food and medicine because of their qualities. Researchers have recently become interested in the immunostimulating effects of microalgae.

The use of algae as animal feed is more frequent than the use of algae in human diets. A vast number of nutritional and toxicological studies revealed that algal biomass can be employed as a beneficial feed supplement that can effectively replace conventional protein sources (soy, fish meal, rice bran, etc.) [65]. Seaweeds are also high in minerals, including salt, potassium, and iodine, as well as fiber. Supplementation of seaweeds to improve the texture of foods is another potential area where their use becomes crucial [66]. Both national governments and intergovernmental organizations have a role to play in re-evaluating the potential of *Spirulina* to meet both their own food security demands as well as a tool for their international development and emergency response initiatives [39]. Algae are high in vitamins, minerals, proteins, polyunsaturated fatty acids, antioxidants, and other nutrients [67]. The enormous potential of microalgae arises from the fact that they are less thoroughly studied than agricultural crops, that they may be cultivated in conditions that are inappropriate for plants (requiring less or no seasonality), and that some species produce several times more than plants. Their potential for producing useful molecules or biomass is generally recognized, and they can be employed to improve the nutritional value of food and feed since they use sunlight energy more efficiently.
