Fig. 3: Metabolism of ornithine from diet confers competitive advantage to Cd and leads to reduced host inflammation.
From: Oxidative ornithine metabolism supports non-inflammatory C. difficile colonization
a, The ornithine oxidative degradation pathway is significantly enriched in mice monocolonized with WT Cd on standard mouse chow compared to mice monocolonized with WT Cd provided a fully defined diet lacking ornithine (row-normalized z score for microarray data from ref. 32; n = 4 mice per group). b, WT Cd has a competitive advantage in conventional mice over ∆oraSE strain in standard diet background, but not in a fully defined diet devoid of ornithine (unpaired two-tailed Student’s t-test, n = 3 mice per group; mean ± s.e.m.). c, 1% ornithine supplementation (w/v) to conventional mice on a fully defined ornithine-free diet provides a competitive advantage to WT Cd (pairwise Student’s t-tests; mean ± s.e.m., n = 5 mice per group). d, WT Cd achieves a higher absolute abundance than ∆oraSE in cecal contents of gnotobiotic mice fed an ornithine-free diet supplemented with ornithine in drinking water. c.f.u., colony-forming unit. e,f, ∆oraSE infection leads to higher levels of lipocalin-2 in serum in gnotobiotic mice harboring a defined consortium of bacteria (e) or conventional mice fed standard diet (f). For d–f data were analyzed by unpaired two-tailed Student’s t-tests; mean ± s.e.m., n = 5 mice per group.
