Beyond advancing age, the factors most commonly blamed for the development of signs associated with skin aging are sun exposure, tobacco and pollution. However, they might not be the only ones, as revealed by research conducted jointly by the Center for Microbiome Innovation (CMI) at the University of California, San Diego, and L’Oréal Research & Innovation. The skin microbiome, ie, the bacteria found on the skin, could also play a central role in the development (or not) of wrinkles, fine lines and crow’s feet.

"Previous studies have shown that the types of microbes on our skin change fairly predictably with age. Our skin also changes physiologically with age; for example, we gain wrinkles and our skin gets drier. But there is variation in what this looks like in people — you’ve probably noticed that there are some people who have younger or older looking skin than many others their age. Using advanced statistical methods, we were able to tease apart the microbes that are associated with these types of aging signs for skin, like crow’s feet wrinkles, from those that are associated with simply age as a chronological number," explains corresponding author, CMI director of research, Se Jin Song, quoted in a statement.

To reach these conclusions, the researchers analyzed data from 13 skin health studies conducted over the past few years by L’Oréal, including more than 650 women aged 18 to 70, based not only on clinical skin data, but also on bacterial identification and classification data. The researchers’ findings, published in the journal Frontiers in Aging, highlight a "positive association" between microbiome diversity and crow’s feet wrinkles, located in the outer corner of the eye. On the other hand, the paper reports "a negative correlation" between microbiome diversity and transepidermal water loss, in other words the amount of water that evaporates through the skin — generally when the cutaneous barrier is impaired due to skin aging.

Micro-organisms of interest

The researchers thus identified several potential biomarkers that warrant in depth investigation. While it would be premature to infer causation or actionable insights from the study’s results, they have provided researchers with directions on the next steps to hone in on better understanding microbial associations with skin aging.

Co-author Qian Zheng, head of advanced research, North America at L’Oréal said: "This research is groundbreaking in identifying new microbial biomarkers linked to visible signs of aging like crow’s feet wrinkles. It marks a significant step towards developing technologies for healthier, more youthful skin. We look forward to sharing new results as they become available, furthering the scientific community’s understanding and contributing to advancing new skincare solutions."

The aim now is to focus on identifying the specific biomarkers of the microbiome linked to skin aging.