Dietary Prevention of Colitis by Aronia Berry is Mediated Through Increased Th17 and Treg.

Scope: Increased fruit consumption is associated with reduced risk of colitis. It has been investigated whether the anti-colitic effects of the polyphenol-rich aronia berry (Aronia mitschurinii 'Viking') are mediated through Th17 and Treg.

Methods And Results: Colitis is induced in recombinase activating gene-1 deficient mice injected with syngeneic CD4 CD62L naïve T cells. Mice consume either 4.5% w/w aronia-berry-supplemented or a control diet concurrent with T cell transfer. The extent of colitis and immunocyte populations are evaluated at weeks 3 to 7 after transfer. Aronia consumption prevents colitic wasting and reduces colon weight/length ratios relative to the control diet at weeks 5 and 7. Compared to the control diet, aronia feeding increases Treg in mesenteric lymph node at all colitis stages. Treg and regulatory Th17 subpopulations (IL-17A IL-10 and IL-17A IL-22 ) are increased in lamina propria and spleen at week 5 in aronia-fed mice. Aronia feeding also decreases total CD4 cells but increases colonic Tregs. The ability of aronia to modulate colonic cytokines is associated with functional T cell IL-10 and increased diversity of microbiota.

Conclusions: Aronia berry consumption inhibits adoptive transfer colitis by increasing Treg and regulatory Th17 cells. Dietary modulation of T cells is dynamic and precedes colitic wasting.