Fig. 2

Inter-individual variations in fibers-induced modulation of microbiota pro-inflammatory potential. The in vitro microbiota MBRA system was inoculated with fecal slurry from 6 healthy donors and stabilized for 72 h, at which point fiber treatment was applied using cellulose, inulin, or psyllium. Microbiota-derived expression of pro-inflammatory molecules lipopolysaccharide (A, C, and D) and flagellin (B, E, and F) were quantified using HEK reporter cells expressing TLR4 or TLR5, respectively. A, B Microbiota-derived bioactive lipopolysaccharide (A) and flagellin (B) levels at the end of the stabilization period (72 h timepoint). C–F For each donor, the evolution of microbiota-derived bioactive lipopolysaccharide (C, D) and flagellin (E, F) levels are expressed as relative value for inulin-treated (C, E) or psyllium-treated (D, F) chambers compared to cellulose-treated chambers. Donor 1 and donor 2 are represented in bolded in all the data related to the use of MBRA system, since they were subsequently used to perform fecal microbial transplantation. Data are the means ± S.E.M (N = 3). In A, B, significance was determined using one-way ANOVA followed by a Tukey’s multiple comparison test, and significant differences were presented as follows: *p < 0.05, **p < 0.01, and ***p < 0.001. In C–F, significance was determined using 2-way group ANOVA corrected for multiple comparisons with the Bonferroni test (# indicates p < 0.05) compared to the control group (Cellulose-treated chambers). Color of the # corresponds to the donor for which statistical significance is reached