Fig. 4: The ability to acquire zinc via yersiniabactin enhances E. coli Nissle colonization of the inflamed gut.

a Experiment timeline for the DSS-induced colitis model and the administration of EcN strains. 8–10-week-old C57BL/6 female mice were given 4% (w/v) DSS in the drinking water for 4 days (day −4 to 0). On day 0, mice were orally gavaged with 1 × 10⁹ CFU of a 1:1 mixture of EcN strains. b, c Fecal samples were collected on day 1, 4, and 7, and the competitive index (C.I.) was calculated by dividing the output ratio. b CFU of wild type or c of the znuA zupT strain / CFU of the competing double or triple mutant strain in each group) by the CFU-enumerated input ratio of the strains. Two-sided one-sample t test was used on log-transformed data to accept or reject null hypothesis (theoretical mean = 0) (black stars). Statistical significance between groups was determined by one-way ANOVA and Dunnett’s multiple comparisons test of log-transformed data (red stars). d Cecal content was collected on day 7 and the C.I. of strains in the indicated groups was calculated as described in b. Two-sided one-sample t test was used on log-transformed data to accept or reject null hypothesis (theoretical mean = 0). e mRNA expression of S100a8, S100a9, and Lcn2 was measured in the colon of mice in panel c. f Colon pathology score of mice in panel d, with sub-scores of each criterion (WT vs znuA zupT n = 8 samples; WT vs znuA zupT irp2 n = 10 samples; WT vs znuA zupT ybtX n = 5 samples; all colon samples are biologically independent). g Representative stained sections (H&E, original magnification ×10, scale bars represent 250 μm) of distal colon from healthy or DSS-treated mice administered with different groups of EcN; sample size as in f. b–e Each data point represents a single mouse (biologically independent samples), and bars represent the geometric mean. The number (=n) of biologically independent replicates for each group is indicated in each figure panel. f Data are presented as mean values  ±SD. *P value ≤ 0.05; **P value ≤ 0.01; ***P value ≤ 0.001; ****P value ≤ 0.0001; ns not significant. Exact P values are reported in Supplementary Data 2. Source data are provided as a Source Data file.