Fig. 2

Drug controlled release and Bac fermentation of NDF-Ms in vitro. A Percentage of 5-ASA release over time. B and C Percentages of proteins and GLCUA left in NDF-M microspheres over time. The in vitro drug release experiment was conducted using SGIF that was used to mimic the in vivo pH environments and transit times of NDF-Ms. 5-ASA, proteins and GLCUA were measured by fluorescence intensity detection, BCA kit and UV–vis at 530 nm, respectively. D Bac growth was observed after NDF-Ms were exposed to SGIF for 0–24 h by measuring the optical density (OD) at 595 nm. E Percentage of Bac at 6 h and 24 h. Data are presented as percentages relative to 0 h. F Representative images of Bac colonies at 0 h, 6 h and 24 h. CFUs were further determined at 0 h, 6 h and 24 h to visualize the bacterial cells. G Correlation analysis between the curve of Bac growth and the curve of the 5-ASA release curve, protein decomposition and GLCUA residual. The coefficients were displayed by the heatmap. H Quantification of the SCFAs. The SCFAs from NDF-M microspheres exposed to SGIF at 24 h were derivatized and measured by LC−MS/MS. These results are reported as the mean ± SD, n = 3. *p < 0.05, **p < 0.01, and ***p < 0.001 versus the NDF-M0 group