Military Training and Skin Bacteria: What Happens to Soldiers' Microbiomes?

The skin is a living shield that protects the body from infections. For soldiers, this shield faces unique tests. Military training, especially outdoor exercises, can change the bacteria living on a soldier's skin. This change happens due to the tough conditions and limited hygiene during training. A study looked at how a 10-day military exercise affected the skin bacteria of 19 Norwegian soldiers. They took samples from the soldiers' hands and forearms before, after, and three weeks post-exercise. The results showed interesting changes. The soldiers' forearms saw an increase in bacterial diversity, while their hands remained stable. This suggests that hands might be more resistant to changes. Both areas showed shifts in bacterial makeup, with soil and water-related bacteria becoming more common after the exercise. These bacteria were temporary on hands but stuck around longer on forearms. During the exercise, the soldiers' microbiomes became more similar to each other. However, after the exercise, their microbiomes started to differ again. Neither the hands nor the forearms returned to their original bacterial makeup. So, what does this mean? It shows that outdoor group activities can greatly influence the bacteria on our skin. It also suggests that different parts of the skin react differently to these changes. Understanding these shifts is crucial for keeping soldiers healthy and ready for action. The skin's bacteria play a big role in protecting the body. Disruptions to this bacterial community can make soldiers more prone to infections. This research can help in managing hygiene and preventing diseases in similar situations. The study also raises questions. Why do hands and forearms react differently? What long-term effects do these changes have on soldiers' health? Further research is needed to fully understand the impact of military service on the skin microbiome. This knowledge can lead to better strategies for maintaining soldiers' health and readiness. It can also help in other fields where people face similar challenges, such as outdoor workers or athletes.