Since the inception of the space program, studying the physiological changes that occur to astronauts has been a major endeavor. In the early days of the space program, there was even a major interest in the role of infectious diseases. Not only were concerns raised regarding astronauts bringing back an alien infection but also concerns regarding returned astronauts being hyper-susceptible to earth microbes. What is also extremely fascinating to me is the effect of space on microbes. A recent piece in The Wall Street Journal contained exciting information in that regard.
It had been well known that space has some sort of salutary effect on microorganisms as evidenced by the proliferation of fungus on Mir. What this article details are several new facets of the space-microbe interaction:
- More resistance
- Faster replication
- Heightened infectivity
Additionally, the microbiome of astronauts changes in space which may play some role in heightened respiratory illnesses and other ailments they suffer from. I also wonder what role the microbiome, with its role in inflammation and myriad disease processes, may have play in the four to five-fold increased cardiovascular death rates seen in astronauts who completed deep space missions vs. astronauts who only participated in low Earth orbit missions.
I suspect that radiation might be the cause behind these phenomena because, without the protection of the atmosphere and magnetosphere of the Earth, organisms are bombarded with higher levels of radiation which can have pleiotropic effects including the inducing of genetic mutations. These mutations, especially in rapidly reproducing bacteria, may speed evolutionary processes and lead to the attributes. The role of changing gravitational forces, which all organisms on Earth evolved in the midst of, likely also has some influence as well. I wonder what the selection pressure is in space that favors the development of the particularly scary characteristics listed above.
Just another reason why infectious disease is the coolest thing ever.