Fig. 1

IL-1Ra deficiency skews intestinal microbial composition and reduces its diversity in a TLR4-dependent manner. a Principal coordinates analysis (PCoA) based on an unweighted UniFrac analysis of the intestinal microbial composition where samples of mice from different cages and litters are highlighted with different colors. The position and distance of data points indicates the degree of similarity in terms of both presence and relative abundance of bacterial taxonomies. b Number of observed operational taxonomic units (OTUs). c Shannon index of microbial diversity. d Alpha diversity rarefaction curves of phylogenetic distance (PD) whole tree. e PD whole tree, bootstrapped for 2000 reads per sample, averaged of four trials. f Chao index are shown. Data (mean + SEM) represent 16S rRNA gene 454-pyrosequencing analysis of intestinal microbiota of WT (n = 9), IL1rn ^−/− (n = 15), IL1rn ^−/− Tlr2 ^−/− (n = 8), and IL1rn ^−/− Tlr4 ^−/− (n = 8) mice. n.s. not significant,*P ≤ 0.05 and ***P ≤ 0.001, by Mann-Whitney U test. See also Additional file 1: Figure S1 and Additional file 1: Table S1