Cutibacterium acnes

Cutibacterium acnes is a Gram-positive bacterium that colonizes human skin. The lipophilic anaerobic bacterium resides mainly in the sebum-rich pilosebaceaous units, but is also detected in nonsebaceous areas. The species is polyphyletic and includes three different subspecies. Multiple phylogenetic lineages usually coexist on an individual’s skin; however, each pilosebaceous unit is predominately colonized by a single lineage. The bacterium is thought to contribute to skin homeostasis through colonization resistance, antioxidant activity, and immunomodulatory properties.