Figure 2. ARM transplantation prevents the loss of intestinal homeostasis caused by antibiotic treatment.

(A) Experimental scheme for ARM administration. Three doses of PBS or ARM were administered daily by oral gavage to C57BL/6 ampicillin-treated mice beginning on day 2 of ampicillin treatment. Fecal samples were collected before antibiotics (d0) and on days 1 (prior to transplant), 4, 8 and 15 after antibiotic initiation. (B) Density of 16S rRNA gene copies in fecal samples over time (n = 5 mice per group). Box plots show the median, 25^th percentile and 75^th percentile; whiskers represent minimum and maximum values (*P = 0.0137, ***P = 0.0009, ****P > 0.0001, Student’s t test). (C) Difference in cecum size among the different groups. (D) Visualization of the inner mucus layer and goblet cells (Muc2) as well as all bacteria (16S rRNA gene) in colon cross-sections. Hoechst dye was used to visualize nuclei. Original magnification, 63X. Scale bars, 10μm. (E) Protein extracts from ileal tissues were analyzed by Western blotting with RegIIIγ-specific antiserum and anti-β-tubulin as loading control. (D–F) Representative images and samples from 5 mice per group are shown. See also Figure S2.