Fig. 3.

Aid^−/− mice have altered gut microbiota, which can transfer body weight gain and IGT to GF mice. Faecal pellets were collected at 12 weeks post-HFD from male Aid^+/+ and Aid^−/− mice, prior to DNA extraction and investigation of microbial composition by 16S rRNA deep sequencing. (a) IgM- or IgA-bound gut bacteria were determined by flow cytometry after staining with fluorescence-conjugated anti-mouse IgM or IgA. (b) α diversity, as assessed by Chao average (to determine species richness). (c) β diversity, as assessed by PCoA. (d) Further microbial changes within the Firmicutes and Actinobacteria phyla. Changes were found at the order (o_Clostridiales), family (f_Peptostreptococcaceae and Lachnospiraceae) and genus (g_; all others) taxonomic levels. (e) Differences in predicted microbial functions following PICRUSt analysis. (f, g) Faecal microbiota from male Aid^+/+ and Aid^−/− mice 14 weeks after HFD were isolated and transferred, by oral gavage, to GF C57BL/6 mice. Ten days later, recipient mice were investigated for changes in their body weight (f) and glucose tolerance (g). Data are from one of two independent experiments, except b–e, which were from one sequence run of the samples from two experiments. n = 4 or 5, except c where n = 5–9. Data were assessed for significance using Student’s t test (a, b, f), Analysis of similarities (ANOSIM) (c), multiple Student’s t test with false discovery rate correction (d, e) or two-way ANOVA (g). Data are presented as mean ± SEM (a) or mean ± SD (b–g). *p<0.05, **p<0.01, ***p<0.001