Does our skin microbiome influence how old we look?

Have you ever tried to guess someone’s age, based on their appearance, only to discover they’re quite a bit younger than you thought?

There’s often a noticeable difference between how old a person looks and their actual (chronological) age, because of features such as wrinkles, altered pigmentation and loss of skin tone.

This difference is linked to the natural decline in physiological functions, such as hormones and cell metabolism. It’s also affected by environmental and lifestyle factors such as exposure to UV radiation and pollution.

A new study by Unilever scientists, published in the British Journal of Dermatology, reveals that the skin microbiome – a diverse community of microbes residing on the skin’s surface – may be an important contributor to the ageing process, and therefore how we look.

“We found that changes in the skin microbiome’s composition and how the microbial members interact with each other are associated with the physiological characteristics of accelerated ageing,” explains Dr Cheri Chu, Microbiome Science Leader, Unilever Global R&D.

“Individuals who appear older than their chronological age tend to have increased microbiome diversity, with higher levels of certain bacteria and lower levels of others, and a more fragile microbiome network structure. We believe that these microbial shifts could influence skin health, contributing to visible signs of ageing.”

Premature versus delayed ageing

In this piece of research, our scientists explored the link between the skin microbiome and the appearance of ageing by comparing people of a similar age, some of whom had features of premature ageing while others displayed delayed ageing.

We found that there were significant differences in the skin microbiome of the two groups. Specifically, we observed an increased abundance of a bacteria called Acinetobacter in those with premature ageing.

We also found that the microbial community – or network – in the premature ageing group was more fragile. Those with delayed ageing had a more resilient and stable microbial community, which may suggest that their skin is better equipped to deal with environmental and physiological stresses.

“You could think of this as like comparing a well-kept garden with diverse, interconnected plants to a neglected garden with sparse, isolated patches of vegetation,” says Cheri. “The well-kept garden is more resilient to pests and environmental changes, while the neglected garden is more prone to being overrun by weeds and suffering from poor health.”

Targeting the skin microbiome to enhance skin health

As part of the study, we looked at how skincare products can affect the appearance of ageing. We did this by giving the participants with features of premature ageing a topical product containing an ingredient called retinyl propionate^[a] to apply for four weeks.

The results were remarkable.

The product not only improved age-related skin physiology but, importantly, it also modulated the microbiome, shifting its composition towards that of individuals with delayed ageing.

It’s the first time this modulation effect has been shown, suggesting that such products can not only improve the look and feel of skin, they can also modulate the microbial biomarkers of ageing.

While this product technology has been around for some time, this aspect of the research gives us a new understanding of how it can be used.

Cheri says: “Our findings unravel the potential role of the skin microbiome in the appearance of premature skin ageing and lay the foundation for the future development of microbiome-based anti-ageing intervention strategies. In other words, products that target the microbiome to improve skin appearance and bolster overall skin health.”