Sun-seeking behaviour on holiday can impact the skin microbiota, new research has found.
In the study, published in Frontiers in Aging, the authors note that the skin microbiota plays a crucial role in maintaining homeostasis in the epidermis, but ultraviolet radiation (UVR) and other environmental challenges can impact the microbiome.
This research was conducted to investigate the effects of sun exposure on the skin microbiota and its relationship with individual skin prototypes.
To explore this question, the researchers had 21 healthy volunteers (four male and 17 female) holiday in a sunny destination for a minimum of seven days. The researchers collected skin swabs both before the holiday and up to 84 days after.
“Here we show in a cohort of holidaymakers that their sun exposure behaviour significantly affects the diversity and composition of their skin microbiota,” said the study’s principal investigator Abigail Langton, PhD, in a press release.
Dr. Langton is a Lecturer in Ethnic Skin within the Centre for Dermatology Research at The University of Manchester, U.K.
“We have demonstrated that the development of a tan is associated with lower Proteobacteria abundance immediately post-holiday. However, the microbiota of all holidaymakers was recovered a few weeks after they stopped spending extended time periods in the sun.”
Analysis of the pre-holiday swabs showed the skin microbiota of the participants was largely made up of three bacterial communities on the surface: Actinobacteria, Proteobacteria, and Firmicutes.
Additionally, each holidaymaker was assigned a group based on individual tanning responses. Eight out of 21 participants, who picked up a tan while on holiday, were deemed ‘seekers.’ The ‘tanned’ group was made up of seven individuals who already had a tan at departure and kept it throughout their holiday. These two groups were classified as ‘sun-seekers.’ The remaining six participants were deemed ‘avoiders;’ their skin tone was the same pre- and post-holiday.
“This study was performed in real-life holidaymakers and provides important insights into how sun exposure resulting in a tanning response—even over a relatively short sunny period—can lead to an acute reduction in Proteobacteria abundance, which decreased skin microbiota diversity,” said Thomas Willmott, PhD, the study’s first author and researcher at the University of Manchester, in the release.
Despite the rapid reduction of Proteobacteria and the accompanying shift in skin microbiota diversity, the bacterial community structure recovered 28 days after individuals had returned from vacation.
“This indicates that UV exposure on holiday has an acute effect on the skin microbiota, but recovery is relatively rapid once the person returns to a less sunny climate,” Dr. Willmott said.
“Proteobacteria dominate the skin microbiota. Accordingly, it is not surprising that there would be rapid recovery of the microbiota to re-establish optimal functioning conditions for the skin,” Dr. Langton said.
The authors state that what might be more concerning is the rapid alteration of microbiota diversity, which has been linked to disease states. A decrease in skin bacterial richness, for example, has been previously associated with dermatitis. Fluctuation in Proteobacteria diversity specifically has been associated with skin problems like eczema and psoriasis.
Future studies should examine why Proteobacteria seem to be particularly sensitive to UVR and how this change in diversity impacts skin health in the longer term, the researchers noted. “Ideally, such studies will aim to increase the number of participants to allow further insights,” Dr. Langton said.