Vitamin D deficiency promotes epithelial barrier dysfunction and intestinal inflammation

Area of Science:

• Immunology
• Gastroenterology
• Nutritional Science

Background:

• Vitamin D modulates the immune system and maintains mucosal barrier homeostasis.
• Vitamin D deficiency's impact on intestinal epithelial barrier function during infection is investigated.

Purpose of the Study:

• To investigate the effects of vitamin D deficiency on intestinal epithelial barrier function in vitro and in a mouse model of Citrobacter rodentium-induced colitis.

Main Methods:

• Caco2-bbe cells were cultured with or without vitamin D and challenged with E. coli O157:H7 to assess barrier function.
• Mice were fed vitamin D-sufficient or deficient diets, infected with C. rodentium, and evaluated for disease severity, permeability, cytokines, and microbiome composition.

Main Results:

• Vitamin D preserved intestinal barrier integrity against E. coli O157:H7.
• Vitamin D deficiency exacerbated C. rodentium-induced colitis, leading to increased colonic hyperplasia and barrier dysfunction.
• Vitamin D deficiency altered fecal microbiome composition.

Conclusions:

• Vitamin D is essential for intestinal epithelial defense against infectious agents.
• Vitamin D deficiency increases susceptibility to severe intestinal injury in infectious colitis models.