Fig. 6: Transplantation of altered gut microbiome from AR-exposed mice into GF mice exacerbates DSS-induced colitis.

a–c 16S rRNA bacterial profiling at the v3–v4 region using cecal contents was carried out. a Bray–Curtis dissimilarity revealed each group of mice possessed distinct microbiota. Each dot represents an individual mouse; n = 4 (Chow) and n = 5 (AR). Box-and-whisker plots illustrate the median, quartiles, maximum and minimum of relative abundance of bacteria b phylum and c genus level. b and c Whiskers are from the 10–90 percentile with a median in the center, and data were analyzed by two-tailed Mann–Whitney U test (n = 4 for Chow; n = 5 for AR). d–m Cecal contents were pooled at equal amounts from SPF C57BL/6 mice either fed normal chow diet or exposed to 100 ppm AR via diet. A 200 μL inoculum was administered to each group of GF mice orally once per day for 3 consecutive days, followed by 21 days of colonization prior to induction of acute colitis with 2.0% DSS for 7 days. All recipient GF mice fed normal chow diet during experiment. d Schematic illustration of the experimental. Red arrow indicates daily gavage. e Body weight change from day 0 to day 28 (where DSS was given during the last 7 days). f Disease activity index (DAI) during DSS. g Macroscopic score. h Colon length (cm). A representative image of colons. i Representative images of H&E-stained colon sections on day 7 post DSS; scale bar: 100 μm. j Histological score. k Colonic MPO levels. l Colonic 5-HT levels. m Colonic IL-1β, IL-6, and TNF-α levels. e, f Data were analyzed by two-way ANOVA with post hoc Bonferroni’s test and are expressed as mean ± SEM (n = 6 for Chow → GF; n = 9 for AR → GF). g–m Data were analyzed by two-tailed unpaired Student’s t-test and are expressed as mean or mean ± SD (n = 6 for Chow → GF; n = 9 for AR → GF). Significance is denoted by *p < 0.05 unless otherwise provided, where *p < 0.05 versus Chow → GF. Source data are provided as a Source Data File.