Figure 7: High-fibre-fed microbiota is structurally different from zero-fibre-fed microbiota, confers protection in DSS colitis associated and increases inflammasome activation.
(a,b) Assessment of structure of microbial communities by unweighted (a) and weighted (b) UniFrac principal coordinate analyses (PCoA) plots are presented for gut bacteria sequenced from mice fed on zero-fibre (ZF), high-fibre (HF) and normal chow diets. (c). Relative abundance of bacteria presented at family level. (d) Pearson’s correlation used to identify the bacteria associated with severity of colitis induced by DSS and the production of the inflammasome-related cytokine IL-18. (e–g) Clinical score (e), colon length (f) and serum IL-18 (g) were determined in GF mice reconstituted with microbiota isolated from HF-fed mice (GF-HF) or from ZF-fed mice (GF-ZF) treated for 6 days on DSS 2 weeks after reconstitution. Mice were fed on normal chow throughout the whole experiment. (h) Caspase 1 activation was measured via a fluorometric assay measuring the cleavage of the peptide YVAD-AFC. NMC460 cells incubated with diluted faecal supernatants from ZF-fed mice (FS ZF) or from HF-fed mice (FS HF) for 4 h and then with 10 mM acetate, 2 mM butyrate and 2 mM propionate for 2 h. The results are shown as mean±s.e.m. with a minimum of five mice per group. With *P<0.05 as a group effect determined by analysis of variance (e), ###P<0.001 determined by Tukey’s multiple comparison test (e) and with *P<0.05 and ***P<0.001 as determined by t-test.
