Skin Microbiome in Healthy Ageing (SMiHA)

The skin is the largest organ of the body and is home to a community of microbiota which generally live in harmony with our human selves. Babies acquire their skin microbiome at birth. This highly specialised and diverse community that exist on all skin sites as well as in the gut, actually provide protection from infection by maintaining a friendly microbe shield against the invasion of pathogenic species into the body. Our 'skin microbiome' is therefore very important to our health and wellbeing. Interestingly evidence shows that this microbial community becomes altered with age - and our skin microbiome composition has been found to be quite an accurate measure of our physical age. The skin also changes as we get older, and this varies according to the body site with skin thinning, dryness and changes in natural oils. The substantial hormonal changes that accompany the menopause cause noteworthy alterations in both the skin and its microbiome that can have significant consequences for female health, such as more frequent urinary tract infections. The very elderly can suffer with chronically infected wounds which are resistant to treatment, while eczema in children is made much worse due to the altered microbiome in the lesions. Our challenge is to make progress in linking skin microbiome to health ageing through our network and to translate this into innovations in everyday products by working with industry partners, to maintain the resilience and health of our skin throughout our whole lives.

The human body and associated microbiome represent an integrated meta-organism, where the microbiota strongly influences human physiology. The human immune system has developed alongside the microbiome to conserve commensal micro-organisms, while eradicating infectious pathogens. However, over the life course, the microbiota composition changes, modulating the immune response resulting in 'inflammageing'. While much is known about gut microbiota in ageing and longevity, the importance of the microbiota in the skin, the largest organ of the body, is only just emerging. Evidence suggests the skin microbiome is a more accurate predictor of chronological age compared to gut, therefore, human skin, with a more stable microbiome than the gut, presents an excellent system to establish how changes in the microbiome over the life course influence biological age (e.g., health status and life expectancy), and conversely how the ageing process drives the microbiome. In the UK, studies on the skin microbiome in healthy ageing are in their infancy and predominately driven by industry, thus presenting a gap in the academic knowledge base which our network 'Skin Microbiome in Healthy Ageing' will seek to address.

Skin disorders occur from tiny infants to the very elderly and some 50% of the UK population suffer a microbiome-associated skin complaint each year, placing a large burden on the NHS. Furthermore, skin health and freedom from chronic skin conditions such as non-healing infected wounds is an important aspect of independence in the elderly population. Without good skin health, day to day living is compromised. Older skin is different, has different composition and structure as well as altered biofilm components, yet our understanding of how to manipulate the skin biofilm - using everyday products - is poor, and so far, only the preserve of those commercial actors who seek to make quick win claims such as 'microbiome friendly skin care' (360,000 hits in google).