Astronauts’ Mice on the Space Station Help Explain Relationship Between Germs and Gravity – Science

“astronaut” mice that spent a period of time in International Space Station (ISS) Worked to prove that the changes in gut bacteria of space travelers may be related to the loss of bone mass experienced by both humans and animals in space. According to the publication, the rodents, which had spent at least one month in the space lab, had altered and more diverse microbes. Cell ReportsThe bacterial species that multiplied may have contributed to the increased production of molecules known to affect Bone remodeling process.

This is “another clear example” of the dynamic interactions between the microbiome and the mammals in which it lives. “Intestinal microbes are constantly watching and interacting, and the same is true when you’re exposed to them Microgravitysaid the study’s lead author, Wenyuan Shi, of the Forsyth Institute in the US.

Researchers have yet to discover whether there is a causal relationship between changes in the microbiota and the bone loss observed in microgravity, or whether it is simply a consequence or effective compensation to mitigate it. “But the data is exciting and opens up new horizons for exploration,” Shi added.

To study how the microbiome changes during prolonged exposure to microgravity, and possible links between these changes and bone density, the researchers sent 20 rodents to the International Space Station.

Ten of them returned to Earth alive after four and a half weeks and their microbiomes were monitored to recover. The other space rodents stayed in orbit for nine weeks. Here, there was a control group with 20 other mice, who were housed in the same conditions as their fellow “astronauts,” except for microgravity.

The team classified and compared the microbial communities of the different groups before take-off, after return to Earth, and at the end of the study.

The researchers also evaluated changes in serum metabolites associated with the gut microbiome of space rodents exposed to microgravity for a period of nine weeks.

It’s the first time in history NASAthe US space agency, to which live rodents are being returned Land, so it was possible to collect not only information about the change in space, but also to monitor the recovery of the microbiome after returning. “The good news is that although the microbiome changes in space, these changes don’t seem to persist on Earth,” Shi said.

Our bones are not fixed, and even in adults, material is always being added, removed, and transformed in a process called bone remodeling. Recent studies indicate that the microbiota can influence bone remodeling through several mechanisms, including the interaction between the immune system and the hormonal system.

Microbes also produce different types of molecules through their metabolism, some of which are directly related to cells responsible for bone remodeling.

Study co-author Joseph K. University of California, Los Angeles (USA).

When the team classified and compared the microbiota of mice on the International Space Station and control animals on Earth, they found that the mice’s microbiota was more diverse. Two types of bacteria — Lactobacillus and Dorea — were more abundant in animals exposed to microgravity and in greater proportions in those who had been in space for nine weeks.

The metabolism of these two bacteria may also have contributed to the higher metabolites detected and associated with exposure to microgravity. “When someone is in microgravity and experiencing bone loss, it makes sense that their bodies would try to compensate and their internal biological systems would try to compensate, but we need to do more studies to really validate these hypotheses,” Bedry said.

If we can learn which microbes contribute to maintaining bone density, it could help astronauts stay healthier. On Earth, this information could also help people with bone loss from causes unrelated to gravity. / EFE