Space tourists experience some of the same body changes as astronauts who spend months in orbit, according to new studies published Tuesday.

Those shifts mostly returned to normal once the amateurs returned to Earth, researchers reported.

Research on four space tourists is included in a series of studies on the health effects of space travel, down to the molecular level. The findings paint a clearer picture of how people — who don't undergo years of astronaut training — adapt to weightlessness and space radiation, the researchers said.

“This will allow us to be better prepared when we’re sending humans into space for whatever reason,” said Allen Liu, a mechanical engineering professor at the University of Michigan who was not involved with the research.

NASA and others have long studied the toll of space travel on astronauts, including yearlong residents of the International Space Station, but there's been less attention on space tourists. The first tourist visit to the space station was in 2001, and opportunities for private space travel have expanded in recent years.

A three-day chartered flight in 2021 gave researchers the chance to examine how quickly the body reacts and adapts to spaceflight, said Susan Bailey, a radiation expert at Colorado State University who took part in the research.

While in space, the four passengers on the SpaceX flight, dubbed Inspiration4, collected samples of blood, saliva, skin and more. Researchers analyzed the samples and found wide-ranging shifts in cells and changes to the immune system. Most of these shifts stabilized in the months after the four returned home, and the researchers found that the short-term spaceflight didn’t pose significant health risks.

“This is the first time we've had a cell-by-cell examination of a crew when they go to space,” said researcher and co-author Chris Mason with Weill Cornell Medicine.

The papers, which were published Tuesday in Nature journals and are now part of a database, include the impact of spaceflight on the skin, kidneys and immune system. The results could help researchers find ways to counteract the negative effects of space travel, said Afshin Beheshti, a researcher with the Blue Marble Space Institute of Science who took part in the work.