According to the CK-12 Foundation, protists are helpful to humans because they produce oxygen, are used in medical research, are an important part of the food chain and are even used in food. In fact, protists help to recycle the nutrients necessary for plant and animal life.
Microbe World points out that just one of the ways protists benefit humans is through their production of oxygen. In fact, nearly one-third of all oxygen comes from protists, not plants. Algae are one of the top producers of oxygen in the protist kingdom.
The University of Alabama states that brown algae, which are part of the protist kingdom and include kelp and seaweed, are an important component of human food. Brown algae are consumed as nourishment in many cultures and contain iodine, which is essential to the proper functioning of the thyroid gland. Protists are also used to thicken certain foods, such as ice cream and pudding, according to the CK-12 Foundation. The main thickener is called carrageenan, which comes from red algae.
According to Science Daily, another group of protists, slime molds, are also being used in technology. One such species called Physarum polycephalum has tubes that allow it to function. In computing technology, these tubes are used to process information and are especially useful for the testing and diagnostics of medical samples.