The human microbiota is the aggregate of microorganisms, a microbiome that resides on the surface and in deep layers of skin (including in mammary glands),[1] in the saliva and oral mucosa, in the conjunctiva, and in the gastrointestinal tracts. They include bacteria, fungi, and archaea. Micro-animals which live on the human body are excluded. The human microbiome refer to their genomes.