Scientist warns longer trips to Mars could have worse effects on astronauts' microbiomes

Researchers are exploring how space affects the human gut microbiome, according to a report by Undark published last week.

David Pearce is a bioscience researcher at Northumbria University and an author of a 2022 paper examining how a space trip might affect microbes in the gut. He is now trying to evaluate whether astronauts will enter a state called dysbiosis, in which their microbiome changes in significant, possibly dangerous ways.

"Because they're going to be away for a long time, will that dysbiosis become a significant problem," he said, "or lead to them having health impacts that impair their ability to function?"

The mitochondria

However, since only about 600 people have ever been to space, this research is hard to conduct. A study conducted in 2020 had found that one biological organelle may lie behind all of these bodily changes in space — the mitochondria. 

Over 200 scientists came together to look into the matter and published 29 papers on the subject in the journal Cell. 

The main question they focused their efforts on was: "Is there a master switch that could be changing your entire body in space?"

They discovered changes in mitochondrial activity ended up being the common thread. 

"As we kept analyzing, certain biological patterns kept popping up," Afshin Beheshti, the co-author of the study and researcher and bioinformatician at NASA for the GeneLab Project, said at the time. 

"The mitochondria was surprising because that wasn't really on my radar, but it connects a lot of these things together."

Meanwhile, in January of 2022, Rachael Dempsey, Communications Officer at Translational Research Institute for Space Health (TRISH) said during a conference at CES 2022 that there are few conventional hazards that still need to be explored when it comes to human space flight.

Isolation, lack of gravity, cosmic radiation, and challenges of performing and executing medical care at great distances from the Earth are on the list.

More information needed

Pearce also argues that there's a need for more information about individual astronauts and their microbial equilibriums. It's currently not possible to evaluate how the human microbiome would change on a long trip to Mars compared to a relatively short stay on the International Space Station, Pearce said.

However, since NASA only plans for such a trip in the late 2030s or early 2040s, researchers could very well find the time and resources to better understand the role the microbiome may play for astronauts' health.

Until that day comes, Pearce said that scientists should continue exploring all research means available to them, including terrestrial studies that recreate space, studies in space itself, and examinations whose goal is to better understand the microbiome of humans that are on Earth. "There's no one way we're going to get an answer for this," he said.

Pearce highlights the need for a multi-pronged approach to explore some of science's most mysterious topics: the effects of space on the human body. Could these concentrated efforts provide the answers scientists are eagerly waiting for?