Living at altitude changes the composition of the skin
Although we know that the diversity of the cutaneous microbiota is influenced in part by the environment, we don’t know the effect of altitude on that ecosystem.
Living at very high altitude exposes the skin to extreme conditions: low atmospheric pressure, lack of oxygen, increased exposure to UV radiation, and cold and dry air. These are all conditions that exert selective pressure on the nature of the germs that make up the cutaneous microbiota.
Whereas the majority of studies on the cutaneous flora were done at low altitude, researchers were interested in the microbial composition of individuals living at high altitude. Starting from the idea that the cutaneous microbiota of mammals living at high altitude differs from that of mammals living at low altitude, they analyzed and compared the cutaneous flora of Chinese and Tibetans living on the Tibetan Plateau, the highest plateau in the world (3750-3861 m) to that of individuals living in the Sichuan Basin (319-1421 m). Their goal was to see if the cutaneous microbiota had adapted to the hostile environment and whether that adaptation allowed it to better resist certain skin diseases caused by extreme conditions.
The results confirmed their hypothesis: the cutaneous microbiota at high altitude was less diverse and was characterized by the presence of five bacterial groups, of which the majority were already isolated in extreme environments. Some of these bacteria are known for their ability to adapt to the cold, improve skin hydration, or protect against UV rays. This suggests an adaptation by the cutaneous flora to protect the skin against the high altitude-specific environment.
Zeng B. et al. High-Altitude Living Shapes the Skin Microbiome in Humans and Pigs. Front. Microbiol. 8:1929.