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Updated: Dec 25, 2025
Cefoperazone-treated Mouse Model of Clinically-relevant Clostridium difficile Strain R20291
Published on: December 10, 2016
Bile Acid Profile and its Changes in Response to Cefoperazone Treatment in MR1 Deficient Mice
Jinchun Sun1, Zhijun Cao1, Ashley D Smith2
1Division of Systems Biology, National Center for Toxicological Research, United States Food and Drug Administration, Jefferson, AR 72079, USA.
Abstract:
Mucosal associated invariant T-cells (MAIT cells) are activated following recognition of bacterial antigens (riboflavin intermediates) presented on major histocompatibility complex class I-related molecule (MR1). Our previous study showed that MR1-/- knock-out (KO) mice (lacking MAIT cells) harbor a unique microbiota that is resistant to antibiotic disruption and Clostridioides difficile colonization. While we have characterized the microbiota of this mouse strain, changes in global metabolic activity in these KO mice have not been assessed. Here, LC/MS-based untargeted metabolomics was applied to investigate the differences in the metabolome, specifically in the bile acid (BA) profile of wild-type (WT) and MR1-/- KO mice, as well as how antibiotics change these profiles. BA changes were evaluated in the intestinal content, cecum content, and stool samples from MR1-/- mice and WT mice treated with cefoperazone (Cef). Fecal pellets were collected daily and both intestinal and cecal contents were harvested at predetermined endpoints on day 0 (D0), day 1 (D1), day 3 (D3), and day 5 (D5). KO mice exhibited no changes in 6-hydroxymethyl-8-D-ribityllumazine (rRL-6-CH2OH; an MR1-restricted riboflavin derivative) in the stool samples at either time point vs. D0, while WT mice showed significant decreases in rRL-6-CH2OH in the stool samples on all treatment days vs. D0. Metabolomics analysis from cecal and stool samples showed that KO mice had more total BA intensity (KO/WT = ~1.7 and ~3.3 fold higher) than that from WT mice prior to Cef treatment, while the fold change difference (KO/WT = ~4.5 and ~4.4 fold) increased after five days of Cef treatment. Both KO and WT mice showed decreases in total BA intensity in response to Cef treatment, however, less dramatic decreases were present in KO vs. WT mice. Increases in taurocholic acid (TCA) intensity and decreases in deoxycholic acid (DCA) intensity in the stool samples from WT mice were associated with the depletion of certain gut bacteria, which was consistent with the previously reported microbiome data. Furthermore, the non-detected TCA and relatively higher DCA intensity in the KO mice might be related to Clostridioides difficile infection resistance, although this needs further investigation.
Insights
Mice lacking MAIT cells (MR1-/- KO) show altered bile acid profiles, with higher total bile acid intensity. Antibiotic treatment impacted bile acids less in KO mice, potentially contributing to resistance against Clostridioides difficile.
Area of Science:
- Immunology and Microbiology
- Metabolomics and Gut Microbiome Research
Background:
- Mucosal associated invariant T-cells (MAIT cells) recognize bacterial antigens via MR1.
- MR1-/- KO mice exhibit a unique, antibiotic-resistant microbiota and resistance to Clostridioides difficile colonization.
- Previous studies characterized the microbiota of MR1-/- KO mice, but their global metabolic activity, particularly bile acid profiles, remained unassessed.
Purpose of the Study:
- To investigate differences in bile acid (BA) profiles between wild-type (WT) and MR1-/- KO mice using untargeted metabolomics.
- To assess the impact of antibiotic treatment (cefoperazone) on BA profiles in both mouse models.
- To explore potential links between altered BA profiles, gut microbiota, and Clostridioides difficile resistance in MR1-/- KO mice.
Main Methods:
- LC/MS-based untargeted metabolomics was employed to analyze BA profiles.
- Samples included intestinal content, cecum content, and stool from WT and MR1-/- KO mice.
- Mice were treated with cefoperazone (Cef) for five days, with samples collected at baseline (D0) and subsequent days (D1, D3, D5).
Main Results:
- MR1-/- KO mice displayed significantly higher total BA intensity compared to WT mice, both before and after cefoperazone treatment.
- While cefoperazone decreased total BA intensity in both groups, the reduction was less pronounced in MR1-/- KO mice.
- WT mice showed increased taurocholic acid (TCA) and decreased deoxycholic acid (DCA) post-antibiotics, correlating with bacterial depletion; MR1-/- KO mice had undetectable TCA and higher DCA.
Conclusions:
- MR1-/- KO mice possess distinct bile acid profiles characterized by elevated total BA and altered specific BA compositions (e.g., higher DCA).
- These unique BA profiles may contribute to the observed resistance of MR1-/- KO mice to antibiotic disruption and Clostridioides difficile colonization.
- Further investigation is warranted to fully elucidate the role of these BA alterations in the context of MAIT cell deficiency and gut microbiome resilience.
