Fig. 1

Salivary microbiota diversity along Mars500 mission and follow-up. a) Timeline of Mars500 mission. Phases were reported in the top part of the panel together with their length in days. The second phase included the landing simulation (20 days) as well as the trip back to Earth (250 days). Diets supplied to crewmembers were reported using different colors, violet for the first food variant, cyan for the second food variant, and yellow for the third food variant. Samples were reported using one point for each crewmember (subject 5001 red, 5002 pale blue, 5003 green, 5004 dark blue, 5005 ochre, and 5006 gray). The days of isolation were reported in the bottom part of the panel. b) Distribution of the main bacterial classes. Panels were divided according to crewmembers (vertically) and diets (horizontally). ASVs with a relative cumulative frequency lower than 5% in all samples were collapsed into a single group called “Other.” c) Differences in alpha diversity—reported using the inverse Simpson index just like panels d, e, and f—between samples collected during and after the isolation period. d) Differences across diets (FV, first variant; TV, third variant; NR, normal diet). e) Differences among subjects. f) Differences along the whole mission and during the follow-up. Points are the average diversity values among subjects whereas error bars represent the 95% confidence interval around the mean. The red line represents the population effect of the linear mixed model whose coefficients are reported in Table S8