The Integrated Impact of Diet on Human Immune Response, the Gut Microbiota, and Nutritional Status During Adaptation to Spaceflight

Spaceflight has demonstrated concerning impacts to human physiology, including well documented immune system dysregulation. Diet, immune function, and the microbiome are interlinked, but diet is the only one of these factors that we have the ability to easily, and meaningfully, alter on Earth or during flight.

Diet may significantly impact physiology, possibly even more than genetics, as demonstrated by abundant ground-based data. Human studies documenting changes in multiple physiological systems simultaneously in relation to diet are limited, in part due to the complexity, and difficulty in accurately monitoring dietary intake over prolonged periods. It is expected that as we understand dietary impacts on physiology more thoroughly, we may continue to improve the spaceflight diet and thus will better support crew health.

We propose here to characterize key effects of the current spaceflight diet compared to an enhanced spaceflight diet on immune function, the gut microbiome, and nutritional status indicators to begin to comprehensively document the effect of dietary improvements on human physiology and their ability to enhance human adaptation to spaceflight. The proposed investigation will provide one of the most comprehensive and interdisciplinary human diet, immune, and gut microbiome studies ever completed in microgravity or on Earth. The outcome will have significant scientific and medical applications for space travelers, and for Earth-bound populations.


Funding for this project provided by NASA.

Principal Investigator


Grace Douglas, PhD
NASA/Johnson Space Center

Brian Crucian, PhD and Scott M. Smith, PhD

Sara R. Zwart, PhD

Robert Ploutz-Snyder, PhD
PstatĀ® and USRA/JSC

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