Relationship between clinical features and intestinal microbiota in Chinese patients with ulcerative colitis

Figure 2 Statistical analysis of the sequencing results of the bacteria microbiota in stool samples from patients with ulcerative colitis and non-inflammatory bowel disease controls. A: The α-diversity of microbiota evaluated by Shannon index. The ordinate shows the Shannon index, and the abscissa shows the groups. Compared with non-inflammatory bowel disease (IBD) controls (Shannon index, 4.71 ± 0.64), the α-diversity of intestinal microbiota evaluated by Shannon index significantly decreased in the ulcerative colitis (UC) in remission (Shannon index, 4.11 ± 0.74; P = 0.013), as well as in the active patients with UC (Shannon index, 3.20 ± 1.04; P = 0.000). The α-diversity of active UC was also significantly lower than that of UC in remission (P = 0.002); B: Principal component analysis. The flora structure of non-IBD controls and UC in remission group showed an obvious difference (with a PC1 of 13.8% and a PC2 of 7.34%, as showed in the abscissa and ordinate axis separately); C: The analysis of similarities. The intergroup difference between non-IBD controls and UC in remission group was greater than within group differences, and the result was significant (P = 0.004); D: The relative abundance of the bacteria at the phylum (the left bar graph) and genus (the right bar graph) levels. The ordinate shows the relative abundance (%), and the abscissa axis shows the sample types where the microbiota was sequenced from. At the phylum level, the abundance of Proteobacteria significantly increased in active UC but decreased in UC in remission, while that of Firmicutes showed the opposite pattern. The abundance of Bacteroidetes significantly decreased in both active UC and UC in remission groups. At the genus level, compared with non-IBD controls, the relative abundance of Alistipes, Bacteroides, Dialister, and Escherichia-Shigella in UC in remission significantly decreased, while that of Lachnospira increased. The relative abundance of Escherichia-Shigella, Enterococcus, and Peptoclostridium was significantly higher in active UC group than in the non-IBD group, while that of Alistipes, Subdoligranulum, Roseburia, Ruminococcus 2, and Ruminococcus torques group was significantly lower in active patients with UC. When comparing active UC and UC in remission, the relative abundance of Escherichia-Shigella, Enterococcus, Haemophilus, and Klebsiella was higher in the former, while that of Lachnospira, Faecalibacterium, Roseburia, and Blautia was higher in the latter. IBD: Inflammatory bowel disease; UC: Ulcerative colitis.