The skin, our body's largest organ, hosts a diverse community of microorganisms like bacteria, fungi, and viruses, collectively known as the skin microbiota. These microbes form complex ecosystems that help defend against harmful invaders.
Extended exposure to UV radiation is linked to DNA damage, skin cell inflammation, and premature aging, despite this, people still engage in sun-seeking behaviors.
Researchers in the UK have delved into the impact of sun-seeking behaviors on the skin microbiota of vacationers, addressing a gap in studies about how individual actions affect UV-related changes in skin microbes and overall skin health.
The study led by Dr. Abigail Langton from The University of Manchester highlights that sun exposure behavior significantly influences the diversity and composition of the skin microbiota in holidaymakers. Interestingly, the development of a tan corresponds to lower levels of Proteobacteria right after the holiday, although the microbiota of all participants returned to their usual state a few weeks after reducing sun exposure. This sheds light on the intricate interplay between sun-seeking habits, microbial balance, and skin health. The findings were published in Frontiers in Aging.
Sun-seeking harms skin bacteria
In preparation for vacations lasting over seven days in sunny destinations, the researchers examined participants' skin before, on day one, day 28, and day 84 after the holiday, focusing on the predominant bacterial communities: Actinobacteria, Proteobacteria, and Firmicutes.
The participants were divided into distinct groups based on their tanning response. Among the 21 participants, eight were ‘seekers,' tanning during the vacation, while seven in the ‘tanned' group already had a tan at the start and maintained it. Both groups were termed ‘sun-seekers.' The remaining six individuals were labeled ‘avoiders' due to unchanged skin tone before and after the holiday.
Dr. Thomas Willmott, the study's lead author from the University of Manchester, emphasized that the study was conducted among real vacationers, revealing how even short-term sun exposure leading to tanning triggers a swift decline in Proteobacteria levels, impacting skin microbiota diversity.
Despite this rapid shift, the diversity of bacterial communities had rebounded within 28 days of participants returning from their vacations. This suggests that while holiday UV exposure promptly affects skin microbiota, recovery occurs swiftly once individuals are back in a less sunny environment, as noted by Willmott.
Microbiota disturbance can cause health problems
“Given the dominance of Proteobacteria in the skin microbiota, it's logical that there's a swift rebound of the microbiota to restore optimal skin function,” pointed out Langton. However, the authors emphasize that the rapid shifts in microbiota diversity, which have connections to various diseases, are potentially more concerning.
Past research has linked reduced richness of skin bacteria to conditions like dermatitis. Notably, alterations in Proteobacteria diversity have been associated with skin issues such as eczema and psoriasis.
The researchers urge future investigations to explore the specific sensitivity of Proteobacteria to UVR and how this diversity shift could affect long-term skin health. Langton stressed the importance of larger participant groups for such studies to yield deeper insights.