What is the relationship between human beings and protists?

Human beings and protists have a complex relationship, as some protists are beneficial while others can be harmful. For instance, certain protists like algae play a crucial role in ecosystems by producing oxygen and serving as a food source. Conversely, pathogenic protists, such as Plasmodium, can cause diseases like malaria. Overall, protists contribute significantly to environmental balance and human health, both positively and negatively.