Fig. 2: Systemic LPS exposure triggers a transient inflammatory response that elevates gut-luminal oxygen species levels.

a Caecal lipocalin-2 levels at 24 h.p.i. in mice systemically exposed to PBS or LPS or orally pre-treated with streptomycin (minimum mice n = 5, at least two independent replicates, ^***P = 0.0002). b Representative images of haematoxylin and eosin-stained caecum tissue at 0, 6, 12 or 24 h post-injection (h.p.inj) or 24 h.p.i. in mice systemically exposed LPS or orally pre-treated with streptomycin. Scale bar=80 µm (mice n = 6, at least two independent replicates). c Caecal lipocalin-2 levels at 0, 3, 6, 9 or 12 h.p.inj. in mice systemically exposed to LPS (minimum mice n = 6, at least two independent replicates, ^**P = 0.0013, ^****P < 0.0001). d Caecum tissue RNAseq at 6 h.p.inj. in mice systemically exposed to LPS compared to PBS. Over-representation analysis of biological processes based on significantly upregulated genes (minimum mice n = 6). e Caecum tissue RNAseq log2 fold change of classical bacterial response genes at 0 and 6 h.p.inj. in mice systemically exposed to LPS compared to PBS (minimum mice n = 6). f Caecal oxygen species levels at 3 h.p.inj. in mice systemically exposed to PBS or LPS, treated with or without streptomycin (minimum mice n = 6, at least two independent replicates, ^**P = 0.0022)^. Bars indicate median values. Dotted lines indicate conservative average limit of detection. P values were calculated using the two-sided Kruskal-Wallis test with Dunn’s multiple test correction (a,c) or two-sided Mann-Whitney U test (f). ns, not significant. Source data are provided in the Source Data file.