For their study, the research team exposed human skin keratinocytes to various kinds of bacteria from the human skin. Out of all the bacteria that were examined, only C. acnes caused a notable increase in lipid generation within skin cells. Notably, it led to a threefold increase in lipid levels, encompassing cholesterol, free fatty acids, and triglycerides. These various fats each play a crucial role in safeguarding the skin barrier.
Dr. Christopher Bunick, an associate professor of dermatology at Yale School of Medicine, who was not involved in the study, says: “[The researchers ultimately showed] that C. acnes-induced lipid accumulation in skin cells directly improves skin barrier function, such as by reducing water loss and increasing antimicrobial activity.”