Effect of killed whole yeast cell prebiotic supplementation on broiler performance and intestinal immune cell parameters.

Two experiments were conducted to study the effect of CitriStim, a commercial killed whole yeast cell prebiotic, on broiler performance, regulatory T cells, CD4(+) and CD8(+) percentages, and IL-10 and IL-1 mRNA contents of the spleen and cecal tonsils. No immune challenges were imposed in either of the 2 experiments. One-day-old broiler chicks were fed a corn- and soybean meal-based diet supplemented with 0, 0.1, or 0.2% CitriStim (ADM, Decatur, IL) for 35 d. At 21 (P = 0.03) and 35 d (P = 0.02) of age, CitriStim supplementation at 0.2% increased regulatory T cell percentage in the cecal tonsil compared with that of the 0% CitriStim-supplemented group. At 21 (P = 0.08) and 35 d (P = 0.01) of age, CitriStim supplementation at 0.2% increased IL-10 mRNA content of the cecal tonsil compared with that of the 0% CitriStim-supplemented group. At 21 (P = 0.13) and 35 d (P < 0.01) of age, CitriStim supplementation at 0.2% decreased IL-1 mRNA content compared with that of the 0% CitriStim supplemented group. CitriStim supplementation did not (P > 0.05) alter the IL-10 and IL-1 mRNA contents in the spleen. CitriStim supplementation did not (P > 0.05) alter the CD4(+) and CD8(+) cell percentages in the spleen and cecal tonsil at 21 and 35 d of the experiment. CitriStim supplementation increased regulatory T cell percentage and IL-10 mRNA content and decreased IL-1 mRNA content in the cecal tonsil to produce a net antiinflammatory milieu. The immunomodulatory effect of CitriStim supplementation was a local effect rather than a systemic effect.