Dietary oligofructose and inulin modulate immune functions in mice

Host defense functions are responsive to diet composition. Since inulin and oligofructose increase resistance to health challenges, selected systemic immune variables were measured in B6C3F1 mice fed diets containing 10g/100g cellulose (C) or with cellulose replaced entirely with oligofructose (OF) or inulin (I), or partially (2.5 g) with oligofructose, (C-OF). White blood cell counts for all groups were within normal ranges, but were 100% higher (P < 0.05) in C mice compared to mice fed fructancontaining diets, which had similar counts. Spleen mass, CD4/CD8 and T/B ratios from suspensions of spleen and thymus, and fecal IgA concentrations did not differ among groups. OF and I mice had higher natural killer cell activity of splenocytes and greater phagocytic activity of peritoneal macrophages. Apparently oligofructose and inulin do not elicit an increase or redistribution of the examined lymphocyte populations (CD4/CD8 and T/B), but up-regulate macrophage-dependent (T-helper 1 type) immune responses in a dose-dependent manner. (C) 2003 Elsevier Science Inc. All rights reserved.