Page 160 - International Space Station Benefits for Humanity, 3rd edition.

combines data obtained from measuring changes Early Detection of Immune Changes
in the gut microbiological composition, metabolites Prevents Painful Shingles in Astronauts
profiles, and the immune system. Recent studies and in Earthbound Patients
indicate that imbalance in gut microbiota composition
results from a variety of environmental stresses and The physiological, emotional and psychological stress
could lead to immune dysfunction. This meta-analysis associated with spaceflight can result in decreased
of the gut microbiota from crew members should result immunity that reactivates the virus that causes shingles,
in better understanding of any immune dysfunction a disease punctuated by painful skin lesions. NASA
they experience. The investigation may identify developed a technology that can detect immune
potential bacterial or metabolic biomarkers for immune changes early enough to begin treatment before painful
dysfunction, which could help the development of a lesions appear in astronauts and in people here on
method to restore gut microbiota imbalance and, in Earth. This early detection and treatment will reduce
turn, immune system function. the duration of the disease and the incidence of long-
term consequences.
Microbiome examines the individual microbiome, or
the collection of microbes living in and on the human Spaceflight alters some elements of the human immune
body at any given time. Researchers use periodic system. Innate immunity—an early line of defense
samples taken from different parts of the body and the against infectious agents—and specific components
space station to monitor crew member microbiomes of cellular immunity are decreased in astronauts.
and immune system function, and their interaction Astronauts do not experience increased incidence
with the unique space station environment. The data or severity of infectious disease during short-duration
enable assessment of the likelihood and consequences spaceflight; however, NASA scientists are concerned
of alterations in the microbiome due to extreme about how the immune system will function over
environments, and the related human health risks. the long stays in space that may be required for
In addition to potentially lowering health risks during exploration missions.
future space explorations, this study could benefit To determine specific causes of decreased immunity
people who live and work in extreme environments in healthy individuals is difficult, but the herpes viruses
on Earth. Results also could advance research in have become valuable tools in early detection of
preliminary detection of diseases, alterations in changes in the immune system, based largely on the
metabolic function, and immune system deficiency.
astronaut studies. Eight herpes viruses may reside in
Rodents such as mice and rats are “model organisms” the human body, and virtually all of us are infected by
whose characteristics make them easy to maintain, one or more of these viruses. Herpes viruses cause
reproduce and study in the laboratory. Every model diseases including common “fever blisters” (herpes
organism has been widely studied, and each has a simplex virus [HSV]), infectious mononucleosis (Epstein-
well-documented and well-understood genetic makeup. Barr virus [EBV]), chickenpox and shingles (varicella
Results from research on one model organism would zoster virus [VZV]). In immune-suppressed individuals,
likely be much the same if conducted on another similar herpes viruses may cause several types of cancer, such
organism. Model organisms tend to be plentiful and as carcinoma, lymphoproliferative disease and others.
inexpensive, have short generation times (i.e., produce
offspring in a short time), and grow relatively quickly.
They are generally less complex than organisms for
which they serve as the stand-in, thus making it easier
to examine the research problem in question. Model These studies demonstrate the
organisms are essential for much research on human
health, which would be impractical or unethical to potential value of bringing to the
conduct with human subjects public a technology that could
The underlying mechanisms behind immune prevent a painful and debilitating
dysfunction caused by living in space are not
well understood. These and other investigations condition in up to one million people
aim to figure out those mechanisms and use that each year in the United States alone.
understanding to help people stay healthy—
in space and on the ground.

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