Which microbe is primarily responsible for causing acne?

Propionibacterium acnes is primarily responsible for causing acne due to its role as a normal inhabitant of the skin's microbiota. This anaerobic bacterium thrives in the sebaceous glands, where it metabolizes sebum (the oily secretion of the skin). In the context of acne, an increase in sebum production can lead to the overgrowth of P. acnes, which contributes to the inflammation associated with acne lesions.

The presence of P. acnes can trigger an immune response, leading to further inflammation and the characteristic symptoms of acne, such as pimples, cysts, and redness. Additionally, the bacterium produces various substances, including enzymes and inflammatory mediators, that can exacerbate skin conditions.

Understanding the specific role of P. acnes in acne development is essential for developing targeted treatments, such as antibiotics that specifically address this bacterium without disrupting the entire skin microbiome.