Fig. 4

a (Left) Copy numbers of the 16S rRNA genes of the Betaproteobacteria were not correlated with serum IL-6 in 22 surviving ARDS patients. (Right) Increased copy numbers of 16S rRNA genes in Betaproteobacteria were correlated with serum IL-6 in 13 non-surviving ARDS patients. b Copy numbers of 16S rRNA genes in the Betaproteobacteria in 16 non-surviving ARDS patients were significantly decreased compared with those of 24 surviving ARDS patients (*P < 0.05). c The relative abundances of Betaproteobacteria in 16 ARDS non-survivors were significantly decreased compared with those of 24 ARDS survivors (*P < 0.05). d Increased copy numbers of 16S rRNA genes of Staphylococcus, Streptococcus and Enterobacteriaceae were correlated with increased serum IL-6 levels in 13 non-surviving ARDS patients. e The ratio of Betaproteobacteria to Staphylococcus, Streptococcus and Enterobacteriaceae did not significantly differ between 24 survivors and 16 non-survivors of ARDS. f The ratio of Betaproteobacteria to the maximum value among Staphylococcus, Streptococcus and Enterobacteriaceae was significantly decreased in 16 non-survivors of ARDS compared with those of 24 survivors of ARDS (**P < 0.01). g Hazard ratio of the ratio of Betaproteobacteria to maximum value among Staphylococcus, Streptococcus and Enterobacteriaceae by the Cox proportional hazards model in 40 ARDS patients (**P < 0.01). IL, interleukin; ARDS, acute respiratory distress syndrome