The Microbiome is made up mainly of bacteria, but also includes fungi, bacteriophages, and even archaea (nonbacterial prokaryotes often found in extreme environments). This microbial population is extremely diverse, and in fact consists of several different and mostly independent communities, each adapted to its own environment. The microbial community in the intestinal tract is very different from that in the vagina, and these are both very different from that in the mouth. Microbial populations live all over our body, from our lungs and gut to inside our nose, mammary glands, and of course all over our skin. Even the insides of our eyelids serve as habitats for microbes.