O
ur bodies don’t react well to
the low-gravity environment
of space. Our muscles don’t have
to work as hard, so they start to
waste away. Our bones get
weaker and our heart pumps
blood slower. To counter this,
astronauts spend two hours each
day exercising to stave off
muscle and bone loss. For a
long-duration mission, we’ll need
to follow a strict exercise plan,
unless we can invent a
spacecraft with its own artificial
gravity so that the body behaves
as it does on Earth.
Past space missions have given
us plenty of insight into the
physical effects of space, but
there’s one major aspect that
has, until recently, been
neglected – the microbiome.
Over the past few years,
scientists have become
increasingly aware of the crucial
role that our body’s army of
microbes plays in our health,
linked to everything from cancer
and obesity to depression and
diabetes. So how might our
microbiome fare in space?
In March 2015, NASA astronaut
Scott Kelly began a year-long
stay aboard the ISS – the longest
that anyone had spent there – as
part of a mission to study the
long-term effects of spaceflight
on the body. Now, researchers
are poring over the data.
“If you’re sending a person into
space, you’re not just sending a
person, you’re also sending
trillions of micro-organisms,”
says Dr Martha Vitaterna of
Northwestern University, oneof the scientists studying
Kelly’s microbiome.
A diverse gut microbiome is
generally thought of as healthy,
but both diet and stress can
change it pretty quickly. Because
Kelly’s diet on the ISS was so
restricted, Vitaterna says that
the team expected to see a
significant decrease in the
diversity of micro-organisms in
his gut, but preliminary results
show that this didn’t happen.
What’s more, any changes that
did take place went back to
normal fairly quickly once he
returned to Earth.
Another NASA project is set to
shed even more light on the
microbiome in space. Earlier this
year, the Rodent Research-7
experiment sent mice to the ISS
in a bid to find out how changes
in the rodents’ microbiomes
impact other aspects of their
health, including their sleep and
circadian rhythm. The results
aren’t expected until next year,
but they should help us to
understand how humans’
microbiomes, and sleep
patterns, might change in space.
And if they back up the Scott
Kelly study, it’ll be good news.
When we do eventually leave
Earth for good, we might lose
bone and muscle mass, but
perhaps we’ll get to keep
our microbes. 7Kelly Oakes is a science writer
based in London. Colin Stuart
is an astronomy author. His
latest book, How To Live In
Space, is out now.STAYING FIT
AND HEALTHY
Make friends with the space gym
“ASTRONAUTS SPEND TWO
HOURS EACH DAY EXERCISING
TO STAVE OFF MUSCLE
AND BONE LOSS.”
NASA X3, GETTY, ESASpace