Propionibacterium acnes is a gram-positive, anaerobic (bacteria that thrive in oxygen-deprived environments) bacterium found in the sebaceous glands of the human skin. They serve as an excellent tool for investigating the anti-acne effect of our test products, as they are commonly associated with the formation of acne on our skin. P. acnes feeds on sebum, producing fatty acids that inflame the hair follicle and stimulate the immune system to release pro-inflammatory chemicals. Debris, dead skin cells, and sebum accumulation create an ideal environment for the bacteria to grow, exacerbating inflammation and leading to acne formation.