Researchers at Northwestern University in the US have recently developed a new tool that shows that spaceflight, both when astronauts are aboard a space shuttle or when they are in the International Space Station (ISS), consistently affects the microorganisms in their gut.
The tool is called STARMAPS (Similarity Test for Accordant and Reproducible Microbiome Abundance Patterns) and it got used to analyse the data from different experiments, including mice samples (ranging from Rodent Research-1 to 7), the US space agency’s Twin Study and Earth-based studies on the effects of radiation on the gut.
As per a wide range of data, mice on the space shuttle and on ISS went through changes similar to that of NASA astronaut Scott Kelly during his 11 months stay in space. The new study also suggests that such changes in microbiomes are most likely to have been caused because of the microgravity, instead of radiation, as per a statement by Northwestern University. The research study was published last month in the journal Microbiome.
“Radiation definitely has an effect on the gut microbiome,” Martha Vitaterna, the lead author of this study said in the statement. “But those effects do not look like what we saw in spaceflight,” she added.
The research looked at mouse samples from the final NASA space shuttle mission, STS 135, which launched in 2011 and also the samples from seven mice groups which were sent to ISS as a part of Rodent Research mission by NASA.
The changes that the researchers observed in the mice groups on ISS were compared to that of a ground control group, a baseline group and a laboratory group that was housed in a conventional mouse facility. In addition to this, data from NASA’s Twin Study which compared physiological changes in NASA astronaut Scott Kelly to his Earth-bound twin, Mark.
Though the research showed that spaceflight does cause changes in the bacterial diversity in the gut microbiome, the exact cause of the change was not very clear.
“There wasn’t a statistical approach for doing this work,” Vitaterna said in her statement. “The tools didn’t exist, so we invented them. It’s a classic case of how necessity is the mother of invention.”
With the help of STARMAPS, the researchers could identify the patterns where different types of bacteria become more or less abundant under different conditions. The study showed similar types of changes in the spaceflight and ground control mice when compared with the other two mice groups.
The data fetched from NASA’s Twin Study also showed a similar pattern of microbiome changes in NASA astronaut Scott Kelly. The findings from the research suggest that gut microbiome changes can be compared among multiple spaceflights, according to the researchers.
“If we are going to send humans to Mars or on long missions to the moon, it is essential to understand the effects of long-term exposure of the space environment on us – and on the trillions of bacteria traveling with us,” Fred W. Turek, the co-author of the study said in the statement.
There were some differences in the microbiome changes that were observed between the mice groups on spaceflight and ground control groups, which showed that the habitat holds the key.
Earlier researches on the radiation effects on mice microbiome did not show the same pattern of microbiome changes so the researchers feel that microgravity might have an effect on the gut microbiome, however further research is needed to be done.
“Understanding what genetic factors contribute to differences in bacterial strains will be useful for developing countermeasures that can protect your microbiome during stressful periods,” Vitaterna said in the statement.