Astronauts have lengthy struggled with constipation in house. Now, scientists might lastly perceive why.
A brand new examine of 52 astronauts who lived aboard the International Space Station (ISS) means that microgravity might sluggish the motion of meals via the intestines, altering how intestine micro organism break down vitamins. The findings may in the end assist researchers develop dietary methods to maintain astronauts’ digestive programs working easily throughout future missions to the moon and Mars — whereas providing new clues about digestive issues right here on Earth, in line with a press release from the College of Copenhagen.
Constipation is a standard downside amongst astronauts, however precisely what occurs inside the gut throughout spaceflight has remained much less clear. To analyze, researchers from the College of Copenhagen and NASA analyzed blood samples collected from astronauts earlier than, throughout and after missions aboard the house station.
“We see modifications in astronauts’ blood samples that point out that the intestine micro organism start to ferment protein to a better extent than common inside weeks after the astronauts arrive in house, and this alteration continues till they’re again on Earth,” Giorgia La Barbera, co-lead writer of the examine and affiliate professor on the Division of Diet, Train and Sports activities, mentioned in the statement.
The staff used a method referred to as metabolomics to measure small molecules circulating within the blood, offering a biochemical snapshot of how the astronauts’ our bodies — and the microbes dwelling inside them — have been responding to spaceflight.
In whole, the researchers analyzed 488 plasma samples from 52 astronauts who spent between two and 9 months aboard the orbiting lab between 2006 and 2018. They recognized modifications in round 40 circulating compounds throughout spaceflight, together with a number of metabolites produced when micro organism within the colon ferment proteins. These compounds elevated whereas the astronauts have been in house, suggesting meals was spending extra time transferring via their intestines, in line with the assertion.
Usually, bacteria within the colon ferment fiber and carbohydrates for power. However when digestion slows, these carbohydrates can turn into depleted, inflicting microbes to interrupt down extra proteins as an alternative and produce completely different metabolites that may enter the bloodstream. The modifications appeared shortly after astronauts entered house and largely subsided inside days of their return to Earth, offering biochemical proof that digestion slows in house. Variations in weight-reduction plan, together with caffeine, fish and fats consumption, accounted for lower than one-third of the metabolic modifications, suggesting weight-reduction plan alone could not clarify the impact.
“The lack of gravity in house most likely causes meals to maneuver extra slowly via the gut, and this suits with the truth that we’re seeing indicators of elevated protein fermentation,” Henrik Roager, co-author of the examine and likewise an affiliate professor on the Division of Diet, Train and Sports activities, mentioned within the assertion. “This may occasionally additionally assist clarify constipation in astronauts.”
Nonetheless, whereas the researchers didn’t instantly measure how shortly meals moved via the astronauts’ digestive programs, the metabolic modifications they noticed counsel that it moved extra slowly via the intestine.
The findings may turn into more and more essential as astronauts spend months — or eventually years — away from Earth. Past the discomfort of constipation, elevated protein fermentation can produce compounds corresponding to ammonia and hydrogen sulfide, and the researchers say a number of the metabolites related to this course of have been linked to different destructive well being results.
One potential countermeasure could also be comparatively easy: more fiber. The staff suggests growing astronauts’ consumption of slowly fermented carbohydrates, which may give intestine microbes extra carbohydrates to devour and scale back their reliance on protein fermentation.
Understanding how microgravity impacts digestion and intestine micro organism may assist preserve astronauts wholesome on more and more lengthy missions to the moon and Mars, whereas additionally providing new clues for treating digestive issues on Earth by revealing how slower motion via the intestine modifications microbial exercise.
Comparable research of astronaut well being in microgravity have additionally yielded insights for folks again on Earth. Bone loss is one distinguished instance. Astronauts lose bone density a lot sooner in microgravity than folks sometimes do on Earth, and efforts to stop that loss have helped scientists higher perceive osteoporosis and age-related bone loss. Spaceflight analysis has additionally supplied insights into muscle loss, cardiovascular well being and immune-system modifications related to getting old and illness.
Their findings have been published June 29 within the journal Nature Communications.
