Fig. 2
Human microbiome metabolites stimulate bacterial motility. a–d Changes in the EHEC transcriptome induced by exposure to human (Hmm) versus mouse (Mmm) gut microbiome metabolites. a Heatmap of differentially expressed genes (red indicates higher levels of expression). b Gene enrichment analysis. c Heatmap of chemotaxis and flagellar assembly pathways showing expression levels for relevant motility-related genes in EHEC cultured in the presence of Hmm versus Mmm. d Schematic of key genes critical in regulating chemotaxis and flagellar assembly in EHEC. e EHEC swimming motility tracking (lines: bacterial movement tracks; dots: starting points for all tracked bacteria; bar, 100 μm). f Quantification of the fraction (%) of moving EHEC. g Mean velocity of each tracked bacterium (red and black: velocity < or > 3 μm s−1, respectively). h Distance traveled (μm) by the moving bacteria. i Fli-C-luciferase expression levels in medium supplemented with Hmm or Mmm [determined by quantifying area under the curve (AUC), and normalizing for the medium control]. *p < 0.05; ****p < 0.0001