SIHUMI mice with both <i>A. muciniphila</i> and <i>S.</i> Typhimurium display increased MUC2 mRNA levels (A) and reduced numbers of mucin filled goblet cells (B and C).

<p>(A) mRNA was extracted from cecum mucosa of mice belonging to either one of four groups: SIHUMI, SIHUMI-A, SIHUMI-S and SIHUMI-AS. MUC2 mRNA from cecum mucosa was converted to cDNA and expression levels were quantified using real-time PCR (see materials and methods). SIHUMI-A and SIHUMI-AS mice showed significantly higher MUC2 gene expression compared to the other two groups, harboring no <i>A. muciniphila</i>. Data are expressed as mean±standard error. n = 6 per group. <i>*P<0.05, **P<0.01, ***P<0.001.</i> Amuc: <i>A. muciniphila;</i> S. Tm: <i>S.</i> Typhimurium. (B) Formalin fixed cecal tissue sections from SIHUMI, SIHUMI-A, SIHUMI-S and SIHUMI-AS mice were stained with alcian blue (pH-2.5) and haematoxylin. Images are representative of 5 mice per group. Magnification 400-fold. SIHUMI-AS mice display the lowest number of positively stained mucin-filled goblet cells compared to the other three groups. The bar represents 100 µm. (C) Quantitative analysis of the number of acidic mucin-filled goblet cells (blue) enumerated in cecal tissue sections from SIHUMI, SIHUMI-A, SIHUMI-S and SIHUMI-AS mice for a 50 µm stretch of lamina muscularis corresponding to approximately 30 cecal crypts per section. Two sections per mouse were analyzed. The number of cecal mucin filled goblet cells was elevated when <i>A. muciniphila</i> was present (SIHUMI-A) but the concomitant presence of <i>S.</i> Typhimurium (SIHUMI-AS) resulted in the lowest number of mucin filled goblet cells of gnotobiotic SIHUMI mice compared to the other mouse groups. Data are expressed as mean±standard error. n = 5 mice. <i>*P<0.05, **P<0.01, ***P<0.001.</i> Amuc: <i>A. muciniphila;</i> S. Tm: <i>S.</i> Typhimurium.