Figure 5. Intestinal Bacteroides are eliminated by antibiotics and stably re-colonize gavaged, antibiotic-pretreated mice independently of host genotype.

(A) Plot of fecal titers from untreated and antibiotic-treated dnKO mice grown in parallel anaerobically on non-selective (ANB) agar and Bacteroides bile esculin (BBE) agar. Titers from individual mice (symbols) and means of log₁₀-transformed titers (bars) are displayed. Unpaired t-test (log₁₀-transformed titers).

(B) Plot of serial fecal titers on BBE agar from antibiotic-pretreated mice gavaged on Day 0 with sterile PBS or B. thetaiotaomicron (7×10⁷ cfu/mouse). Individual titers (symbols) and means of log₁₀-transformed titers (lines) are displayed. Unpaired t-tests comparing log₁₀-transformed fecal titers from B. thetaiotaomicron-gavaged dnKO mice to Il10r2^+/− mice.

(C) Frequency histogram of all 92 B. thetaiotaomicron fecal titer measurements (log₁₀-transformed) we have performed on individual, single-isolate-gavaged, antibiotic-pretreated mice regardless of mouse genotype. Fecal titers were performed between 6 and 20 days post-gavage; data are compiled from multiple independent experiments with 4–9 mice per experiment. Gavage doses ranged from 6.6×10⁷ to 8.6×10⁸ cfu/mouse. Excluding the single outlier value (8.78), the titers are normally distributed as assessed by the D’Agostino & Pearson K² omnibus normality test: p = 0.5894, K² = 1.057, skewness = −0.153, kurtosis = 0.3345. Statistical analysis performed using GraphPad Prism v5.01 (GraphPad Software).

See also Figure S4