Aronia consumption downregulates mRNA expression of pro-inflammatory cytokines and up-regulates anti-inflammatory cytokines. Splenic CD4+CD62L+ cells from C57BL/6J mice were transferred to Rag1-/- mice. Mice consumed the AIN-93M diet (colitic control) or aronia-supplemented diet for five weeks. A third group of Rag1-/- mice received splenic CD4+ cells, consumed AIN-93M diet and served as the non-colitic control. The mRNA expressions of transcription factors of Foxp3 (forkhead box P3) and Rorc (RAR-related orphan receptor gamma), and cytokines of Il17a (interleukin 17A), Il22 (interleukin 22), Il6 (interleukin 6), Il10 (interleukin 10), Ifng (interferon-gamma), and Tnf (tumor necrosis factors) in the (A) colon (n = 4–5/group), (B) mesenteric lymph node (MLN) (n = 8–10/group), and (C) spleen (n = 3–5/group). The mRNA expressions were normalized to Eef2 (eukaryotic translation elongation factor 2) and Rplp0 (ribosomal protein large P0) genes. Data are means ± SEMs.