Fig. 1

Dynamics of gut microbiota composition and diversity in ICU patients and healthy subjects. a Principal component analysis (PCA) of gut microbiota composition of ICU patients. Dashed symbols indicate fecal samples collected after ICU discharge and continued hospitalization in a medium-care ward. Fecal samples that were collected in the first 5 days of ICU hospitalization are indicated by a black line around the symbol. Fecal samples of healthy subjects were collected at two time points with 1-year interval, indicated with black and gray circles, respectively. b Diversity (Shannon index) of the microbiota of ICU patients. Double lines indicate hospitalization in a medium-care ward. c Diversity (Shannon index) of the microbiota of healthy subjects. d Gut microbiota composition of patients and healthy subjects. Stacked bar charts represent the abundance of different major taxa in the gut microbiota of ICU patients and healthy subjects. Among Bacilli, the genus Enterococcus has been highlighted, as SDD has previously been shown to select for colonization with enterococci [36, 37]. Fecal samples that were collected after ICU discharge and during medium-care hospitalization are indicated by gray triangles. Statistically significant differences of the abundance of taxa in the gut microbiota of patients during ICU hospitalization and healthy subjects are indicated in the legend (*q < 0.05; **q < 0.01; ***q < 0.001; Mann-Whitney U test with Benjamini-Hochberg correction for multiple testing)