Microalgae are widely distributed and are found in soil, swamps, fresh water, hot springs, and can also grow in extreme environments that are not suitable for other organisms, such as lakes with high salinity. There are many kinds of microalgae, such as chlorella, spirulina and other edible microalgae are rich in protein, carotene, various vitamins, algal polysaccharides, polyunsaturated fatty acids, chlorophyll, etc. The protein content of microalgae is very high, and the algal polysaccharide complex contained in microalgae can be used as an immune adjuvant to enhance antigenicity and immune function of the body, play an anti-tumor effect, and increase its value as a prebiotic. The carotenoid content in microalgae is very high, which has the effect of coloring and nutrition. Microalgae can also be used as raw materials to produce food additives such as vitamins and food colorings or extract phycocyanin, chlorophyll, astaxanthin, carotenoid I, Vegetarian and other food coloring. In recent years, food additives with health functions such as EPA, DHA and other polyunsaturated fatty acids and polysaccharides have also been researched and developed from microalgae. Spirulina and other microalgae prebiotics can be selectively absorbed after entering the body, increasing the number of bifidobacteria and enhancing the body's immunity. Because of this, it has been recommended by the United Nations Food and Agriculture Organization as "the most ideal health food for human beings in the 21st century". [4]
In the past 30 years, the rapid development of the spirulina biotechnology industry in industrialized production at home and abroad, the large number of products, and the high output value have made a sudden emergence in the field of microalgae industry, which has attracted the attention of the world. The large-scale industrial production of spirulina contains huge potential economic potential. The development of spirulina resources is not only conducive to the development of new nutritional sources, alleviation of energy and food crisis, but also to promote the transformation of traditional agriculture to modern agriculture. [4]
Natural plants
my country is rich in Chinese herbal medicine and natural plant resources. In recent years, there has been an upsurge in the use of natural herbal medicines to prevent and treat various diseases. Chinese herbal medicine is a kind of substance with dual functions of nutrition and medicine. It can regulate the balance of intestinal flora and improve the morphological structure of the intestine. The active ingredient extracts of Chinese herbal medicine and natural plants can be used as important prebiotic products.