A few outfit tweaks can take us from a day in the office to a night out on the town. Our skin, too, can be surprisingly changeable—reacting to cosmetics, climate and hormonal fluctuations throughout life. Its long-term condition is also deeply shaped by ageing, including transformative life stages such as puberty and menopause.
The skin’s surface hosts a thriving community of microbes that are far more than passive residents. These microorganisms play vital roles in maintaining balance and health by converting skin lipids into complex signalling molecules known as oxylipins, some of which can trigger inflammation, while others calm it down. Even familiar microbes can play dual roles: a lipid-loving bacterium known as Cutibacterium acnes, for instance, supports a healthy skin barrier yet is also infamous for its role in acne.
“By studying the interaction between the skin microbiome, lipidome and biological age, we can understand how ageing affects skin health and potentially uncover new ways to prevent inflammation and disease,” said Thomas Dawson, Deputy Executive Director at A*STAR Skin Research Labs (A*STAR SRL). However, most earlier studies have examined skin microbes or lipids in isolation, and involved small participant groups or lacked diversity in age or ethnicity.
To derive more holistic insights, Dawson and collaborators sought to profile both the oxylipins and microbial composition of skin samples from a diverse, population-based cohort. The multidisciplinary team spanned several institutions—the A*STAR Genome Institute of Singapore (A*STAR GIS) and A*STAR Institute of Human Development and Potential (A*STAR IHDP), alongside the National University of Singapore and Nanyang Technological University, Singapore. They drew on two long-term studies: GUSTO (Growing Up in Singapore Towards healthy Outcomes) for data on children up to the age of puberty, and HELIOS (Health for Life in Singapore) which includes adult participants across different life stages, including peri- and post-menopausal women.
Through integrated analyses, the team found that C. acnes is more abundant on adult skin, representing a third of the total skin microbiome, compared to less than one percent in pre-pubescent children. The bacterium was also twice as abundant in pre-menopausal women than post-menopausal women. Furthermore, adults had elevated levels of fungi such as Malassezia restricta and Malassezia globosa, which rely on skin lipids to survive.
When the researchers grew skin cells in the lab with Malassezia species, the yeasts produced common skin oxylipins and promoted the secretion of immune signalling molecules that may enhance or suppress inflammation. “These findings hint at a functional relationship where microbes play an active, mechanistic role in modulating skin inflammation through lipid-derived signalling molecules,” said Dawson.
Moving forward, the team is investigating how changes in the microbial composition contribute to dryness, itchiness and other skin discomforts that often accompany menopause. “Ultimately, this could guide the development of skincare products designed to restore microbial balance and improve skin health in post-menopausal women,” said Dawson.
The A*STAR-affiliated researchers contributing to this research are from the A*STAR Skin Research Labs (A*STAR SRL), A*STAR Genome Institute of Singapore (A*STAR GIS) and A*STAR Institute of Human Development and Potential (A*STAR IHDP).
