Biological System
Microbiome Composition
Shifts in gut and skin microbial communities
Overview
The gut microbiome — trillions of bacteria, fungi, and other microorganisms — influences immunity, metabolism, and even cognition. In the closed environment of a spacecraft, microbial communities shift. The Inspiration4 metagenomics studies profiled stool (OSD-630), skin swabs from 10 body sites (OSD-572), and environmental capsule surfaces (OSD-573) across 8 timepoints.
Key findings
- Gut microbiome composition (OSD-630) showed individual-specific trajectories; no single taxon shifted consistently across all crew.
- Skin microbiome (OSD-572) reflected the shared capsule environment — some site-specific convergence was observed.
- Capsule surface microbiome (OSD-573) tracked crew skin and oral communities, consistent with prior ISS research.
- Pathway abundance data (HUMAnN3) is used here rather than raw species counts for interpretability.
Individual trajectories
fold-change from L-44 baseline · n=4Pathway abundance fold-change from pre-flight median. n=4 for gut; capsule samples reflect environmental, not individual, data.
Microbiome Composition · C001
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Microbiome Composition · C002
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Microbiome Composition · C003
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Microbiome Composition · C004
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Related dashboard domains
How to read this page: These findings describe four individuals at one point in time. No finding should be generalized to spaceflight health broadly. Individual differences dominate the signal. Fold-changes labeled “2× individual baseline” use derived thresholds, not clinical cutoffs.