Fig. 4

The bacterial profile in fecal samples of UC patients with or without oral ulcers. A Alpha diversity indices of the microbiota, including the richness, Simpson’s, Shannon’s, and Chao1 indices. Horizontal bars within boxes represent medians. The tops and bottoms of the boxes represent the 75th and 25th percentiles, respectively. The upper and lower whiskers cover 1.5 × the interquartile range from the upper and lower edges of the box, respectively. P-values were obtained using the one-way ANOVA test (comparisons among four groups). B The constrained principal coordinate analysis based on the Bray–Curtis distance. The R software (v 4.0.1) with the vegan (v 2.5–7) package were used, and P-values were obtained using permutational multivariate analysis of variance (PERMANOVA). C, Relative abundance of the top 20 bacterial families (the left panel) and genera (the right panel). Visualization was performed using Circos (http://circos.ca/). The right circle in the outer part shows the groups and relative proportions of bacterial species. The left outer circle and inner bands show the relative proportions (%) of bacterial genera in the different groups. The left inner circle represents the relative abundances of all bacteria. D and E, Comparative analysis of bacterial genus abundance between two groups (D UC_OU vs. OU; E UC_OU vs. UC). The EdgeR package was used for comparative analysis. The difference between the two groups is shown as a Manhattan diagram. Point shape indicates the genus enriched, depleted, or not significant in the former group compared with the latter. Point size indicates the counts of a specific genus. CPM, count per million. F and G, Comparative analysis of bacterial function between two groups [F UC_OU vs. OU; G UC_OU vs. UC]. Phylogenetic Investigation of Communities annotated the pathway information by Reconstruction of Unobserved States (PICRUSt2) software by referring to the Kyoto Encyclopedia of Genes and Genomes (KEGG) database. The STAMP software was used for data visualization. CON, healthy controls; OU, patients with only oral ulcers; UC, UC patients without oral ulcers; UC_OU, UC patients with oral ulcers; ns, not significant; *P-value < 0.05; **P-value < 0.01