Metagenomic and metatranscriptomic sequencing of 750 samples from 8 body sites (skin, oral, nasal, gut) plus spacecraft surfaces, at 8 timepoints. Identifies which species are present, their relative abundance, and which genes they're actively expressing.
Reading this chart
Y-axis shows Shannon diversity index — higher = more diverse microbiome. The drop from 3.8 to 2.7 during flight means fewer species dominating (less healthy). This happened because crew members shared microbes in the confined capsule. Partial recovery post-flight as individual microbiomes re-diversified.
Microbiome composition affects immune function, metabolism, and even mental health. In the confined spacecraft environment, crew members rapidly exchanged microbes — their microbiomes converged. Shifts in gut bacteria can indicate stress, dietary changes, or immune suppression.
Relative abundance percentages (what % of bacteria are Species X). Alpha diversity (Shannon index — how diverse is one person's microbiome). Beta diversity (Bray-Curtis — how similar are two people's microbiomes). All standard ecological metrics.
All AP-level math. No differential equations, no ML required. With n=4, descriptive statistics are more honest than hypothesis testing.
Rapid microbial interchange between crew members
Skin microbiome showed largest shifts
Functional gene expression changed (not just composition)
Partial reversion post-flight but not complete
Supporting data for Immune Regulation domain. Microbiome diversity loss correlates with immune suppression. The crew-to-crew transfer visualization is compelling — shows shared living environment effects.