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Updated: Jun 9, 2025
Analyzing Beneficial Effects of Nutritional Supplements on Intestinal Epithelial Barrier Functions During Experimental Colitis
Published on: January 5, 2017
Candida tropicalis-derived vitamin B3 exerts protective effects against intestinal inflammation by promoting
Ha T Doan1, Li-Chieh Cheng1, Yi-Ling Chiu1
1Department of Life Science, National Taiwan University, Taipei, Taiwan.
Abstract:
Candida tropicalis-a prevalent gut commensal fungus in healthy individuals - contributes to intestinal health and disease. However, how commensal C. tropicalis influences intestinal homeostasis and barrier function is poorly understood. Here, we demonstrated that the reference strain of C. tropicalis (MYA-3404) ameliorated intestinal inflammation in murine models of chemically induced colitis and bacterial infection. Intestinal colonization of C. tropicalis robustly upregulated the expression of IL-17A and IL-22 to increase barrier function and promote proliferation of intestinal epithelial cells in the mouse colon. Metabolomics analysis of fecal samples from mice colonized with C. tropicalis revealed alterations in vitamin B3 metabolism, promoting conversion of nicotinamide to nicotinic acid. Although nicotinamide worsened colitis, treatment with nicotinic acid alleviated disease symptoms and enhanced epithelial proliferation and Th17 cell differentiation. Oral gavage of C. tropicalis mitigated nicotinamide-induced intestinal dysfunction in experimental colitis. Blockade of nicotinic acid production with nicotinamidase inhibitors lowered the protective effects against colitis in mice treated with C. tropicalis. Notably, a clinical C. tropicalis strain isolated from patients with candidemia lacked the protective effects against murine colitis observed with the reference strain. Together, our results highlight a novel role for C. tropicalis in resolving intestinal inflammation through the modulation of vitamin B3 metabolism.
Insights
The gut fungus Candida tropicalis helps maintain intestinal health by boosting barrier function and cell repair. It achieves this by altering vitamin B3 metabolism, converting nicotinamide into protective nicotinic acid.
Area of Science:
- Microbiology
- Immunology
- Gastroenterology
Background:
- Commensal fungi like Candida tropicalis are common in the gut but their role in intestinal homeostasis is unclear.
- Understanding how C. tropicalis influences gut barrier function and inflammation is crucial for its role in health and disease.
Purpose of the Study:
- To investigate the mechanisms by which commensal Candida tropicalis affects intestinal homeostasis and barrier function.
- To explore the impact of C. tropicalis colonization on intestinal inflammation and epithelial cell proliferation.
Main Methods:
- Murine models of chemically induced colitis and bacterial infection were used to assess the effects of C. tropicalis.
- Intestinal colonization, gene expression analysis (IL-17A, IL-22), metabolomics, and in vivo functional assays were employed.
- Comparison between a reference strain and a clinical strain of C. tropicalis was performed.
Main Results:
- The reference strain of C. tropicalis ameliorated intestinal inflammation and upregulated IL-17A and IL-22, enhancing barrier function and epithelial proliferation.
- C. tropicalis altered fecal vitamin B3 metabolism, promoting the conversion of nicotinamide to nicotinic acid, which alleviated colitis symptoms.
- A clinical strain of C. tropicalis from candidemia patients did not show protective effects against colitis.
Conclusions:
- Candida tropicalis plays a protective role in resolving intestinal inflammation through modulation of vitamin B3 metabolism.
- Nicotinic acid, promoted by C. tropicalis, enhances epithelial barrier function and Th17 cell differentiation, offering therapeutic potential.
- Strain-specific differences exist in the protective functions of C. tropicalis against intestinal inflammation.
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