Fiji analysis was based on 5 representative images per mouse, n = 10 mice/group. longum, and B. longum subsp. Next, we examined whether B. dentium could grow in minimal medium in the presence of free oligosaccharides that are typically found in mucin (Fig. Much remains unknown about how the intestinal microbiome interfaces with the protective intestinal mucus layer. C1157; Thermo Fisher) for 30 min at 37°C anaerobically, similar to previous bacterial staining reports (190, 191). It is interesting to note that B. dentium is routinely present in samples from caries, whereas only one of either S. inopinata or P. denticolens will be present in any one sample, suggesting that there is a kind of mutual exclusion operating here (Modesto et al., 2006). 2B to L). This finding was confirmed by demonstrating that B. dentium could not use naive mucin glycans as primary carbon sources in vitro. Cells were routinely tested for Mycoplasma contamination using the Mycoplasma detection kit (catalog no. Adult germfree Swiss Webster mice (male, n = 21; female, n = 23) were orally gavaged with either sterile de Man-Rogosa-Sharpe (MRS) medium, live B. dentium MRS cultures (2 × 108 bacteria), or heat-killed B. dentium (2 × 108 bacteria) every other day for 1 week. B. dentium adheres to intestinal MUC2.Adhesion to the intestinal mucus layer is considered a prerequisite for colonization by mucosa-associated bacteria and represents a selection criterion for probiotic microbes (91). Some members of this species have a beneficial effect on us just by being within us because they can cause immune Acetate and heat-killed B. dentium had no effect on mucin expulsion (Fig. This finding is consistent with the prediction that B. dentium cannot extensively degrade mucins, and several species are likely to be necessary to modulate mucus sufficiently to affect cecum size. For adhesion assays, 100 μl of mucus solution (1 mg/ml) was immobilized in 96-well polystyrene microtiter plates (Maxisorp, Nunc; VWR) by overnight incubation at 4°C, as previously described (70). Probiotics can be defined as a food (feed) or drug containing live microbes that, when ingested, is expected to confer beneficial physiologic effects to the host animal through microbial actions (1). According to single-cell sequencing of mouse intestinal epithelium, the acetate receptor GPR43 (also known as FFAR2) is highly expressed in goblet cells (Single Cell Portal; Broad Institute), and acetate may directly modulate GPR43 to stimulate MUC2 production. They are found in the highest numbers in the colon (large intestine), although they only amount to 3-6% of the total flora in adult feces. No significant differences were observed in terms of mouse body mass between germfree, live, or heat-killed B. dentium-monoassociated groups (day 17 germfree, 40.5 ± 5.6 g; live B. dentium, 42.5 ± 4.8 g; heat-killed B. dentium, 39.5 ± 5.3 g). 8D to F). Supplementation of purified germfree cecal MUC2 or MUC2 derived from the human mucin-producing cell lines LS174T or HT29-MTX at 1 mg/ml did not enhance B. dentium growth in LDMIV without glucose. Table 1 summarizes some of these functions and effects as well as possible mechanism. Similar to other markers of goblet cells, Muc2 mRNA was also increased in B. dentium-monoassociated mice compared with germfree and heat-killed B. dentium controls (Fig.
