'NASA Twins' study shows spaceflight effects on the human body
Asian News International
The findings published in the journal 'Science' are among the results from 10 other research teams examining how the human body responds to spaceflight that is reported in the paper.
The twins involved in the study were astronaut
The two brothers, who were 50 years old at the time of the study, provided biological samples and underwent a battery of cognitive and physical exams before, during and after Scott's flight.
While hundreds of humans have flown in space before, there is little data on how space flight longer than a few months impacts health and the body.
The goal of the
Teams of researchers from around the nation analysed the data and reported their findings on the biochemical, cognitive, ocular, genetic, physiological, immunological and other changes in the Science paper.
Green, together with colleagues
"Our role in the
The gut microbiota helps digest food, fights infections and plays an important role in keeping the immune system healthy. It is greatly influenced by genetics, stress, diet and other environmental factors.
Previous research has implicated an unhealthy or unbalanced microbiota as a contributing factor to metabolic disorders, including obesity and diabetes. The species that make up an individual's gut microbiota, as well as their abundance, can be identified by stool sample or faecal swab analysis.
Faecal swabs were collected from both twins twice before Scott's departure from Earth, four times during Scott's time on the space station and then three times upon his return to Earth.
"There seems to be a small but significant effect on the microbiome caused by spaceflight; however, the makeup of Scott's gut microbiome returned to his baseline pretty quickly upon his return to Earth," Green said.
"Whether the changes are due to the different food, microgravity, or radiation we can't say definitively, but I believe the effect was caused by differences in what he was eating while in flight. An astronaut's diet consists of mainly freeze-dried or thermo-stabilized prepackaged food," Green added.
One of the changes Green and his group noticed was a shift during flight in the ratio of two dominant phyla of bacteria: the Firmicutes and Bacteroidetes.
Scott's ratio between these two phyla changed while he was in space, with the ratio of these two phyla increasing about five-fold relative to his baseline. But at no time during the spaceflight were the ratios outside the norms of what you would expect in healthy individuals, Green explained. And, Scott's ratios rapidly returned to where they were before his space mission once he returned to Earth.
Green and colleagues also saw no changes in levels of microbial diversity during Scott's time on the space station.
"Diversity remained constant for Scott during his time in space, and this is, from my perspective, a positive finding suggesting substantial resilience and robustness in the gastrointestinal microbiota," he said.
According to Green, knowing about changes to the microbiome in space is important, in part because if diversity or key species are lost, there are fewer sources to replenish them.
He said isolation and confinement are some of the main obstacles related to long-duration missions, and these factors could negatively affect the astronaut gut microbiome.
"The overall small and transient effect of extended spaceflight on the gut microbiome we saw in
"This should be taken in context, however, of the fact that this is a study of a single individual in low Earth orbit, and future studies are needed to confirm this finding," he continued. (ANI)