Depiction of the human body and bacteria that predominate<unk> , also called<unk>  microbiota, refers to microbiota (communities of microorganisms) that reside on the<unk> , typically human<unk> . Many of them are bacteria of which there are around 1,000 species upon human<unk>  from nineteen phyla. Most are found in the superficial layers of the epidermis and the upper parts of hair follicles.<unk>  is usually non-pathogenic, and either commensal (are not harmful to their host) or mutualistic (offer a benefit). The benefits bacteria can offer include preventing transient pathogenic organisms from colonizing the<unk>  surface, either by competing for nutrients, secreting chemicals against them, or stimulating the<unk> 's immune system. However, resident microbes can cause<unk>  diseases and enter the blood system, creating life-threatening diseases, particularly in immunosuppressed people. A major non-human<unk>  is Batrachochytrium dendrobatidis, a chytrid and non-hyphal zoosporic fungus that causes chytridiomycosis, an infectious disease thought to be responsible for the decline in amphibian populations.
Skin flora
Vaginal flora
Disease vector
Indicator bacteria
Microgenia
Biomedical tissue
Pathogenic bacteria
Human body