Acne bacteria trigger cells to produce fats, oils and other lipids essential to skin health – new research
The skin is the largest organ of the body, and it plays a crucial role as the first line of defense against pathogens and insults from the external environment. It provides important functions like temperature regulation and moisture retention. And despite the misconception that lipids harm your skin by causing oiliness and acne, they actually play a vital role in maintaining the skin barrier.
I am a researcher in dermatology working in the Gallo Lab at the University of California, San Diego. My colleagues and I study how the skin defends the body against infections and the environment, with a particular focus on the skin microbiome, or the microbes living on the skin. In our recently published research conducted in collaboration with SILAB, a company developing active ingredients for skincare products, we found that C. acnes triggers certain skin cells to significantly increase production of lipids that are important to maintaining the skin barrier.
Skin bacteria and lipid synthesis
To determine the role that bacteria play in lipid production, we exposed keratinocytes, the cells that make up the epidermis, to different bacteria naturally present on the skin and analyzed changes in lipid composition.
Of the common skin bacteria we tested, only C. acnes triggered an increase in lipid production within these cells. More specifically, we found a threefold increase in total lipids, including ceramides, cholesterol, free fatty acids and especially triglycerides. Each of these lipid types are essential to maintaining the skin barrier, locking in moisture and protecting against damage. These findings suggest that C. acnes plays a distinctive role in the lipid skin regulation.
We found that C. acnes induced this increase in lipid production by producing a type of short-chain fatty acid called propionic acid. Propionic acid creates an acidic skin environment that provides a number of benefits, including limiting pathogen growth, reducing staph infections and contributing to anti-inflammatory effects in the gut.