Shifts in intestinal microbiota during TNBS-induced inflammation The PCR-DGGE fingerprints SN-38 in vivo showed changes of the composition
and diversity in gut microbiota of the twelve groups of fish (Figure 5A). The first eight lanes represent the DGGE profiles of control and TNBS-exposed fish harvested at 4 dpf, whereas the lanes 9 to 16 represent the profiles of fish at 6 dpf and the last twelve lanes are the profiles at 8 dpf. At each of the time point, the gel shows the DGGE profiles of 4 groups: control (F1-F2, S1-S2, E1-E3), 25 μg/ml TNBS-exposed (F3-F4, S3-S4, E4-E6), 50 μg/ml TNBS-exposed (F5-F6, S5-S6, E7-E9) and 75 μg/ml TNBS-exposed (F7-F8, S7-S8, E10-E12). The dendrogram based on DGGE banding similarity patterns showed that samples from different time points were separated into three different clusters (Figure 5B), indicating the establishment of the gut microbiota during zebrafish development from 4 to 8 dpf. At 8 pdf, Akt inhibitor in vivo the microbial composition in the control and TNBS-exposed groups especially the 75 μg/ml TNBS-exposed group had a significant variation, whereas at 4 and 6 dpf, the community profiles were not clearly distinct.
It revealed TNBS exposure resulted in intestinal microbiota alteration GW2580 solubility dmso by 8 pdf. The alternations of Shannon-Wiener diversity indices according to the intensity of bands were showed in Figure 6. As we can see, during the bacterial colonization of the zebrafish gut from 4 to 8 dpf, the biodiversity of Miconazole intestinal microbiota was increased. Meanwhile,
larvae exposed to TNBS had a lower community diversity of gut bacteria compared to control group at 8 dpf. Figure 6 Biodiversity of microbiota composition in zebrafish with TNBS-induced IBD. All error bars represent as mean ± SEM. n=6 samples per group, a Indicates a significant difference (p<0.05) between TNBS-exposed group (25 μg/ml) and the control, b Indicates a significant difference (p<0.05) between TNBS-exposed group (50 μg/ml) and the control, c Indicates a significant difference (p<0.05) between TNBS-exposed group (75 μg/ml) and the control, d Indicates a significant difference (p<0.05) between control groups at 6 dpf and 4 dpf, e Indicates a significant difference (p<0.05) between control groups at 8 dpf and 4 dpf. Bacterial species associated with inflammatory disorder In order to define the key members of intestinal microbiota that likely contributed to the pathogenesis of TNBS-induced inflammatory disorder, we further identified the alteration of the dominant bacterial species in zebrafish gastrointestinal tract. Nineteen sequences of 16S rRNA gene fragments were obtained and sequenced. These genes were assigned to 19 bacterial phylotypes based on the highest sequence similarity (95–100%) matched to GenBank sequences obtained by BLAST analysis (Figure 5A, Table 2). We next quantified the relative abundance of fragments in DGGE profiles of the 19 bacterial phylotypes (Figure 7).