Vitamin A and vitamin D regulate the microbial complexity, barrier function, and the mucosal immune responses to ensure intestinal homeostasis

Abstract

Diet is an important regulator of the gastrointestinal microbiota. Vitamin A and vitamin D deficiencies result in less diverse, dysbiotic microbial communities and increased susceptibility to infection or injury of the gastrointestinal tract. The vitamin A and vitamin D receptors are nuclear receptors expressed by the host, but not the microbiota. Vitamin A- and vitamin D-mediated regulation of the intestinal epithelium and mucosal immune cells underlies the effects of these nutrients on the microbiota. Vitamin A and vitamin D regulate the expression of tight junction proteins on intestinal epithelial cells that are critical for barrier function in the gut. Other shared functions of vitamin A and vitamin D include the support of innate lymphoid cells that produce IL-22, suppression of IFN-γ and IL-17 by T cells, and induction of regulatory T cells in the mucosal tissues. There are some unique functions of vitamin A and D; for example, vitamin A induces gut homing receptors on T cells, while vitamin D suppresses gut homing receptors on T cells. Together, vitamin A- and vitamin D-mediated regulation of the intestinal epithelium and mucosal immune system shape the microbial communities in the gut to maintain homeostasis.

Keywords:

• Vitamin A
• vitamin D
• microbiota
• nutrition
• gastrointestinal tract
• mucosal immune system

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the National Institutes of Health, National Center for Complementary and Integrative Health [R01AT005378], United States Department of Agriculture [2914–38420-21822], and United States Department of Agriculture National Institute of Food and Agriculture/Hatch Appropriations [Project: #PEN04605, Accession #1018545].