Phylogenetic differences associated with survival. (A) At the phylum level, levels of Bacteroidetes was unchanged, while levels of Firmicutes was significantly enriched in patients that died versus those that did not. (B) At the species level, there were 4 specific species (Eubacterium biforme, Ruminococcus flavefaciens, Akkermansia muciniphila, and Oxalobacter formigenes) that were enriched in the gut microbiota of patients that died versus those that did not (P<0.05).