NLRP3 deficiency eliminates the protective effect of A. muciniphila in colitis. (A) Experiment design of the mouse model for acute DSS-induced colitis in NLRP3−/− mice. (B) Weight loss in the wild-type or NLRP3−/− mice with or without A. muciniphila treatment. (*, wild-type-A. muciniphila compared to wild-type-PBS; #, NLRP3−/−-PBS compared to wild-type-PBS). (C and D) Mice were sacrificed on day 16, and the colon length and spleen weight were measured. (E to G) Representative pictures of H&E-stained mouse colon tissue in the wild-type and NLRP3−/− mice with or without A. muciniphila treatment. The histology score was the sum of the inflammation damage, inflammation infiltration, and crypt damage scores. (H and I) Representative pictures of alcian blue- and PAS-stained colon tissue in the wild-type and NLRP3−/− mice with or without A. muciniphila treatment. Red arrows, inflammation cells. Data are expressed as the mean ± SD or standard error of the mean (SEM); n = 5 per group. *, P < 0.05; **, P < 0.01; ***, P < 0.001; ****, P < 0.0001; ns, no significance (ANOVA test). Akk, Akkermansia muciniphila.