Figure 3. Gut microbiota in suckling mice plays a critical role in CR infection-caused lethality.

(A) Live C. rodentium (CR) recovered from the fecal samples of 21-day-old germ free (GF) wild-type (WT) and C1qc^−/− mice at 7 and 14 days post inoculation (dpi) with 2 × 10⁹ CFU of CR.

(B-C) Body weight changes (B) and survival (C) of 21-day-old GF WT and C1qc^−/− pups at indicated dpi with 2 × 10⁹ CFU of CR.

(D) Live CR recovered from the fecal samples of 21-day-old GF C1qc^−/− pups, reconstituted at postnatal 17 days (P17) with the cecal and colonic microbiota derived from P21 specific pathogen free (SPF) WT or C1qc^−/− pups, at 7 dpi with 2 × 10⁹ CFU of CR.

(E-G) Body weight changes (E), survival (F), and clinical scores (G) of 21-day-old GF C1qc^−/− pups, reconstituted and infected as in (D), at indicated dpi.

(H) Lengths of the colon derived from GF C1qc^−/− pups, reconstituted and infected as in (D), at 12 dpi.

(I) GF C1qc^−/− pups were reconstituted and infected as in (D). FITC-dextran concentrations in the sera of GF C1qc^−/− pups (12 dpi), at 4 hours after oral administration of FITC-dextran.

(J) Species abundance heatmap of the dominant 35 genera detected using 16S rRNA gene-based high-throughput sequencing among the cecal and colonic contents derived from 21-day-old WT (n=5), C1qc^−/− (n=4), and C3^−/− (n=5) pups.

Data are mean ± s.e.m., with specific n numbers indicated. Data in A-C are combined results from two independent experiments; in D-G are combined results from three independent experiments; in H and I are representative results of three independent experiments. ns, not significant; * p < 0.05, ** p < 0.01, *** p < 0.001, and **** p < 0.0001.

See also Figures S4 and S5.