Fig. 2

DSS alters diversity of gut microbiota in mice models of colitis. A Pielou index. B Shannon index. α-diversity was derived using a combination of the species richness (species situation) and species evenness (distribution) using the Pielou and Shannon indices. C Gut microbiota relationships and distribution are characterized with a UPGMA clustering tree. Samples are represented by end branches. In general, samples belonging to similar groups were clustered into a large branch with different branches representing different groups. Distance is indicated by the vertical axis. Samples with similar structure of bacterial communities are located in the same branch. D NMDS (Non-metric Multi-Dimensional Scaling). NMDS representas a dimension reduction analysis established on distance ranking. It is superior to linear models (including PCA and PCoA) and more accurately translates the nonlinear structure of ecological data. The accuracy of the model is evaluated by the stress value. The smaller the stress value is, the more reliable the model is. Generally, the stress value less than 0.1 is better. **P < 0.01