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.crew who showed this effect
- Skin microbiome (OSD-572) reflected the shared capsule environment — some site-specific convergence was observed.crew who showed this effect
- Capsule surface microbiome (OSD-573) tracked crew skin and oral communities, consistent with prior ISS research.crew who showed this effect
- Pathway abundance data (HUMAnN3) is used here rather than raw species counts for interpretability.crew who showed this effect
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. Values labeled “2× individual baseline” use derived thresholds, not clinical cutoffs.
Individual trajectories
change from own pre-mission level · n=4fold-change from L-44All crew · Microbiome Composition●●●●Trajectory chart renders after preprocessing
Pathway abundance change from pre-flight median. n=4 for gut; capsule samples reflect environmental, not individual, data.