All of us depend upon food crops for sustenance, and in turn these crops depend on healthy soils with its balanced microbial life. Much of the protein that we eat is the result of bacterial fixation of nitrogen from the air from microbes such as Rhizobium. Many of our foods are prepared with the aid of microbes, such as yeast in bread, and lactobacilli in yogurt.
Many of our food supplements, from vitamins, amino acids to flavor enhancers and preservatives, come from microbes.
Some of our foods are microbes, such as salted yeast paste found in Vegemite, and single cell protein.
Although not a food, microbes are used as probiotics, a digestion supplement that colonizes the intestines, preventing the colonization of bad, disease-causing microbes.