Fig. 3: Increased bacterial translocation in Muc2^−/− littermates.

a Bioluminescence of XEN-14 E. coli treated and control animals were recorded post 24 h LPS treatment. LPS-treated Muc2^−/− exhibited increased luminescence corresponding to higher translocation of intestinal bacteria as compared to Muc2^+/+ littermates. Graph shows representative data from two independent experiments. b Fluorescence in situ hybridization (FISH) using Alexa 555-conjugated EUB338 universal probe for bacterial rRNA in mouse intestinal tissue 24 h post LPS challenge to visualize translocated gut bacteria. Tissues were fixed in Carnoy’s, paraffin embedded, sectioned, and FISH staining was done using established protocol. Nucleus was stained with DAPI and mucus with UEA1-TRITC lectin. Representative images are from three independent experiment, n = 3. Graph shows distance calculated from epithelium to the nearest bacteria (select straight line from epithelium to the bacteria and then analysis tab). In total 25 events were calculated from each area of view and plotted as Means ± SEM. c Quantification of fecal IgA⁺ bacteria in Muc2^−/− and Muc2^+/+ littermates. Age and sex-matched animals were used to collect fecal samples in sterile condition. Graph shows cumulative data of two independent experiments (n = 5/experiment) and plotted as mean ± SEM. d, e Higher bacterial growth in the serum of d Muc2^−/− littermates (n = 10) and e active UC patients, suggesting higher predisposition towards septicemia (n = 5/group). A fixed number of non-pathogenic E. coli was added to heat-inactivated serum and O.D. was recorded at given time points at 600 nm. Data are representative of three independent experiments, paired one-way ANOVA. Data are presented as means ± SEM. *p < 0.05, **p < 0.01, and ***p < 0.001.