Extended Data Fig. 1: Faecal SCFAs are associated with IgA levels in mice and humans.
From: Acetate differentially regulates IgA reactivity to commensal bacteria
a, Correlation of total major SCFAs, acetate, propionate and butyrate with SIgA concentration in faeces of antibiotic-treated mice. Mice were administered the following antibiotics via ad libitum drinking water: vancomycin (orange), neomycin (red), ampicillin (aqua), metronidazole (purple) and distilled water (grey) for 2 weeks (n = 4 per group). Faecal samples were sequentially collected at weeks 1 and 2. Total major SCFAs is the sum of acetate, propionate and butyrate. b, Association of human faecal metabolites with SIgA concentration (n = 17 per group). All faecal samples were dichotomized according to the IgA concentration and the relative intensity of specified metabolites was compared between the IgA-low and IgA-high groups. c, Relative intensity of faecal acetate, propionate and butyrate was compared between the IgA-low and high-groups. d–f, Ileal, caecal and colonic concentrations of acetate (d), propionate (e) and butyrate (f) in mice fed the fibre-deprived cWSCA (control)-containing or WSCA-containing diet (n = 4 per group (d), n = 4 per group (e) and n = 4 versus 3 (f)). g, h, Faecal concentration of SCFAs in mice fed the cWSCP (control) or WSCP diet (g), and cWSCB (control) or WSCB diet (h) (n = 4 per group). i, Faecal concentration of SCFAs in mice fed a standard chow diet (CE2, CLEA Japan) (n = 8). c, Box plots indicate the median, upper and lower quartiles, and upper and lower extremes except for outliers. d–i, Data are mean and s.d. *P < 0.05, **P < 0.01, ***P < 0.001; Spearman’s rank-order correlation (a), two-sided Wilcoxon rank-sum test (c) and Kruskal–Wallis test with Dunn’s test (d–i). Exact P values are provided in the Source Data.
