Fig. 3

Differential abundance of bacteria based on flight status. a ALDEx2 statistically analysis was performed on sequences summarized to the phylum level. Significance was based on the Benjamini-Hochberg corrected p value of the Wilcoxon rank test (significance threshold P < 0.05). Out of the nine phyla detected in saliva, three showed statistically significant differences as a result of spaceflight. The changes in their relative abundances between pre-flight, in-flight, and post-flight are shown with boxplots. The box in each graph signifies the 75% (upper) and 25% (lower) quartiles and thus shows the percent abundances for 50% of the samples. The black line inside the box represents the median. The bottom whisker represents the lowest datum still within the 1.5 interquartile range (IQR) of the lower quartile, with the top whisker representing the highest datum still within the 1.5 IQR of the upper quartile. Open circles are outliers. b In half of the subjects tested, three genera, Catonella, Megasphaera, and Actinobacillus were not present in pre-flight samples, but were detected in samples collected during flight. In those that already had these genera pre-flight, their relative abundances increased in-flight. The read counts for these three organisms in all ten subjects are shown in a heatmap. Gray indicates that no reads were detected while a gradient from green to red shows low counts and high counts, respectively