Evidence is now shining a spotlight on how much space missions take a toll on humans' immune systems. At least 29 cases of infectious diseases being contracted on board a spacecraft were reported on during a 2012 study that looked into 106 flights and 742 crewmembers. Head colds, fungal infections, and gastroenteritis were just some of the ailments that overtook the participants of the study. What may be worse is the fact that they are million miles away from home and do not get to have sufficient bed-rest or comfort foods while under the weather.

It could be noted as quite an oddity, that space illness does not get the hype that it most likely deserves. "The immune system can go on the fritz in space: wounds heal more slowly; infection-fighting T-cells send signals less efficiently; bone marrow replenishes itself less effectively; killer cells- another key immune system player-fight less energetically," states a 2012 piece published by Time.

In space, pathogens enjoy an easy time growing strong and creating a resistance wall to antimicrobials. Specifically, herpes and staph have been reported as thriving in gravity-free environments of a spacecraft that are in extremely sterile conditions.

One particular study, which was released this week, checked out the space-born Drosophila flies. Specimens of this type are often examined because of how close in comparison the flies' immune system is to that of humans. It was discovered that in the instance of fungal infections microgravity wiped out the immune's response.

The researchers also studied the centrifuge-induced hypergravity, discovering that the flies' immune responses to fungi heighten as gravity increases way beyond the normal range. On a lighter note, the immune response in the space flies to bacteria was mentioned as being "robust".

Fungal and bacterial infections in humans and Drosophila flies are governed by two different cellular paths. Fungus is mediated by Toll receptors and the other one through a gene named imd. For the Toll path, it seems to operate in a balanced state to gravitational field power while the imd looks like it does not mind either way.

Some speculate that space trips involve the development of "heat shock" proteins, which cling to Toll path receptors and cut down the immune system' detectors for finding pathogens. The end result is a small reaction to a possibly huge pathogen risk.

Induced gravity through the use of centrifuge seems to be the best bet at solving immune system errors, an idea thought of as resourceful for keeping on top of bone and muscle mass. Increasing astronauts' immunity would be a plus for their experience on space missions.

Source: Voice of Russia