Urban living decreases skin bacterial diversity

Urbanisation leads to a vast decrease in bacterial diversity and an increase in chemical diversity on the skin, a keynote lecture on the skin microbiome will reveal today at the 29^th EADV Congress, EADV Virtual.[i]

Urbanisation is associated with reduced outdoor exposure, increased contact with housing materials, antimicrobials and cleaning products, and increased exposure to synthetic chemical diversity. Through urbanisation, the natural human and plant-based molecules on the hands and skin are largely replaced by synthetic and cosmetic ingredients with an increase in potentially pathogenic bacteria, stress-tolerant bacteria, potentially pathogenic fungi and fungal biomass. These can have a profound impact on skin health and can be associated with typical Western skin pathologies. [ii]^,[iii]

Dr Chris Callewaert, a senior postdoctoral research fellow of the Research Foundation - Flanders at Ghent University, Belgium, and postdoctoral research associate in the Knight lab at University of California, San Diego, USA, says: “Urbanisation represents a profound shift in human behavior, with significant cultural and health-associated consequences. It is really interesting the see that indigenous people, such as African hunter-gatherers and Amerindians, never suffer from acne, eczema, psoriasis, skin allergies, oily skin, dry skin or even skin cancer. There might be something in their microbiome that protects them. We found huge losses of bacterial diversity on skin with urbanisation, and more potentially pathogenic bacteria and fungi on Western skin. These can have a direct impact on our skin health. We have many things to learn from indigenous people, and should go back to basics in order to restore a healthy skin microbial equilibrium.”  

This study was a collaborative investigation by Dr Dominguez-Bello, Dr Knight, Dr Dorrestein, Dr Paulino, and many other leading researchers. It represents the first systematic investigation into the effects of urbanisation on the skin microbiome and metabolome.

[i] Callewaert C. Impact of urbanization on the skin microbiome. Presented 31 October 2020 at EADV Virtual.

[ii] McCall, L.I., Callewaert, C., et al M.G. Home Chemical and Microbial Transitions across Urbanization. Nature Microbiology. 2020;5(1):108–15.

[iii] Callewaert, C., Ravar Helffer, K., Lebaron, P. Microbiota and their interplay with the environment. Am J Clin Dermatol. 2020. https://doi.org/10.1007/s40257-020-00551-x.