Cutibacterium acnes (also known as C. acnes) is a bacterium that normally lives on healthy human skin.
Formerly known as Propionibacterium acnes, it is a natural part of the skin microbiome. Rather than causing acne by itself, it contributes to acne when combined with blocked hair follicles, excess sebum, inflammation, and other biological factors.
Quick fact
Finding Cutibacterium acnes on the skin is normal—even in people without acne.
Commonly confused with
A contagious germ
See also