After weeks of traveling in Bolivia, it is time to dive back into the immune system! Last time, we looked at an overview of microbes and more closely at the first category: fungi. This week, we will examine our next two microbes: protozoa and algae. We are connecting how the world around us impacts our bodies’ defense systems. Remember, many microbes are extremely beneficial to humans. They remove wastes and toxins; recycle that waste; keep our mouths, skin and gut healthy; act as enzymes and breakdown our food; and perform many other incredible unseen functions!
Protozoa are single-celled animals, classified into three groups based on their shape: “Ciliates are the largest and move by means of hair-like cilia. They eat the other two types of protozoa, as well as bacteria. Amoebae also can be quite large and move by means of a temporary foot or "pseudopod." Flagellates are the smallest of the protozoa and use a few whip-like flagellas to move.”  Some protozoa live in freshwater, moist and fungal rich soils, and even humans.
When protozoa latch onto humans, they are classified as a parasite. As parasites they cause diseases, particularly in a patient with a suppressed immune system. Malaria is a life-threatening disease that is typically transmitted through the bite of an infected mosquito which carries the protozoa Plasmodium. When an infected mosquito bites you, the parasite is released into your bloodstream. 
On the flip side, there are many beneficial roles protozoa play. For example, in the soil, as they feed on bacteria they regulate the bacterial populations. This actually stimulates the growth of the bacteria and improves soil decomposition and aggregation, and the mineralization of nutrients (making them available for use by plants and other soil organisms). Protozoa are also an important food source for other soil organisms and help to suppress disease by competing with or feeding on pathogens. Thus, these microbes indirectly support our immune system by optimizing minerals in the soil which are then absorbed in our food.
Algae are single-celled and multi-celled microbes that have no roots, stems, or leaves but do have chlorophyll and other pigments for carrying out photosynthesis. They range in size from microscopic to giant kelp that reach 200 feet in length. Algae live in fresh or seawater where they can either be free-floating or attached to the bottom. With enough moisture, some algae can grow on rocks, soil or plants. Others partner with fungi to form lichens (slow-growing plants on rocks, walls, and trees). This microbe plays many essential roles in our ecology, including a food source for most of aquatic life and provides oxygen through photosynthesis. It also provides an amazing superfood for our immune system and overall health! Spirulina and chlorella are two algae that are packed with vitamins, minerals, antioxidants and proteins. They have been shown to support weight loss, heavy metal detoxification, and heart health; lower inflammation; and fight cancer.  You can consume both of these in an organic powder, capsule, or liquid form for daily immune system support.
Next time we will wrap up this section of the immune system, “Our Microbial World,” with a look at bacteria and viruses.