Newly Identified Molecules from Blood Bacterium Show Promise in Combating Skin Aging

People often use masks, lotions, and serums in an effort to maintain youthful-looking skin.

Researchers have now identified compounds with anti-aging properties that come from within the body. A type of bacterium found in the blood produces three compounds that reduce damage and inflammation in human skin cell cultures.

These findings, published in the Journal of Natural Products, could lead to new treatments for aging skin.

Scientists still know relatively little about how bacterial byproducts—known as metabolites—released into the bloodstream affect human health. One group of metabolites, called indole compounds, is of particular interest because of its anti-aging, anti-inflammatory, and antibacterial properties.

The blood bacterium Paracoccus sanguinis, which produces indole compounds, was first identified in 2015. Chung Sub Kim, Sullim Lee, and their colleagues became interested in P. sanguinis and studied the effects of its indole-functionalized metabolites.

We became interested in P. sanguinis because blood-derived microbes are a relatively uncharted area of research. Given the unique environment of the bloodstream, we believed that studying individual species like P. sanguinis could reveal previously unknown metabolic function relevant to health and disease.”

Chung Sub Kim, Department of Biopharmaceutical Convergence, Sungkyunkwan University

The researchers grew a large batch of P. sanguinis over three days before extracting the metabolites produced by the bacteria. They used a combination of methods—including spectrometry, isotope labeling, and computational analysis—to identify the chemical structures of 12 distinct indole metabolites. Six of these had not been previously reported.

Next, Kim, Lee, and their colleagues tested whether these indole metabolites could reduce aging-related effects in human skin cells. They added liquid solutions containing each indole to wells with cultured human skin cells. Before the experiment, the cells were treated to raise levels of reactive oxygen species, which contribute to inflammation and the breakdown of collagen.

Three of the 12 indoles, including two newly identified ones, lowered the levels of reactive oxygen species in the stressed cells compared to untreated controls. These three compounds also reduced the levels of two inflammatory proteins and a protein involved in collagen degradation.

Based on these early results, the researchers consider the novel indole metabolites promising candidates for future treatments targeting skin aging.