Splenic T cell and intestinal IgA responses after supplementation of soluble arabinoxylan-enriched wheat bran in mice

- Wheat bran increased the population of mouse splenic CD4 T cells.
- Wheat bran-treated mice showed reduced generation of Th2 cells.
- Secretory IgA level in the small intestines was increased by wheat bran treatment.

Wheat bran contains a high level of arabinoxylan. We investigated whether wheat bran affects the composition and immune responses of splenic T cells and the mucosal IgA response of small intestines in mice. Mice were fed soluble arabinoxylan-enriched wheat bran for 4 weeks. Wheat bran increased the population of CD4(+) T cells. When splenocytes from each group were stimulated with anti-CD3 antibody, there was no change in proliferative capacity, but a significant decrease in expression of the early activation marker CD69 was observed in the high-dose group. With regard to T cell-derived cytokines, levels of interleukin (IL)-2, IL-10, and interferon-γ were unaffected but that of IL-4 was decreased in mice receiving wheat bran. Further, wheat bran increased mucosal and luminal secretory IgA levels in the distal small intestine. Our results suggest that wheat bran affects systemic and intestinal immunity and can be developed as an immunoenhancing functional food.