PSXI-6 - Effects of a Saccharomyces Cerevisiae Fermentation Product-supplemented Diet on Circulating Immune Cells and Oxidative Stress Markers of Dogs

Abstract: Feeding Saccharomyces cerevisiae fermentation product (SCFP) has previously altered fecal microbiota, fecal metabolites, and immune cell function of adult dogs. The objective of this study was to further measure circulating immune cell numbers and activity, antioxidant status, and oxidative stress marker concentrations of adult dogs fed SCFP in an extruded diet. Sixteen adult pointer dogs (8M, 8F; mean age = 8.35 y; mean BW = 27.13 kg) were used in a randomized crossover design study. All dogs were fed a control diet for 4 wk, then randomly assigned to the control or SCFP-supplemented diet and fed to maintain BW for 10 wk. A 6-wk washout preceded the second 10-wk experimental period with dogs receiving opposite treatments. After baseline/washout and treatment phases, pre- and post-prandial blood samples were collected. Oxidative stress and immune cell function were measured using commercial ELISA kits, circulating immune cell numbers were analyzed using flow cytometry, and mRNA expression of oxidative stress genes were analyzed using RT-PCR. Change from baseline data were analyzed using the Mixed Models procedure of SAS 9.4, with P< 0.05 being significant and P< 0.10 being trends. Changes in unstimulated lymphocytes and stimulated IFN-g secreting T-cells were lower (P < 0.05) in SCFP-fed dogs, while change in stimulated T cells were lower (P < 0.05) in control-fed dogs. The stimulated cytotoxic T cells delta trended lower (P < 0.10) in SCFP-fed dogs. Change in serum superoxide dismutase (SOD) concentrations were higher (P < 0.05) and change in catalase mRNA expression was lower (P < 0.05) in SCFP-fed dogs. All other immune cells, oxidative stress markers, and gene expression were unaffected by treatment. In conclusion, SCFP-fed dogs have increased SOD, which supports lower acute-inflammatory responses and aligns with some immune stimulation data.