48-2 |
Potential immune modulators in dairy foods |
K. L. ERICKSON1, D. S. Kelley2, and N. E. Hubbard1. (1) Dept. of Cell Biology & Human Anatomy, Univ. of California, Davis, School of Medicine, Davis, CA 95616-8643, (2) USDA-ARS-Western Human Nutrition Research Center, PO Box 29997, San Francisco, CA 94129 A number of components found in dairy foods may act to alter specific or nonspecific immunity. Of the many dietary components found in dairy products, conjugated linoleic acid (CLA) and probiotic bacteria are thought to potentially modulate immunity. While some investigators report that feeding of diets containing CLA to rodents enhanced splenocyte proliferation, IL-2 production, and macrophage phagocytosis, others found no effect of CLA on similar parameters of immune function. To determine whether CLA would enhance human immune status, a mixture of CLA isomers were fed to healthy women in a metabolic research unit for 93 days. None of the indices of immune status tested including number of circulating leukocytes and their subsets, response to mitogen or recall antigens, or macrophage cytolysis, were altered by dietary CLA during the study. Thus, short-term mixed isomer supplementation in healthy women was safe, but did not have any added benefits to their immune status. Cultured dairy products containing probiotic bacteria may play an important role in modulation of immune function. Probiotics such as Lactobaccilus acidophilus and Bifidobacterium bifidum have been shown to enhance several components of an immune response such as humoral or nonspecific immunity. Although the specific results vary, generally enhanced secretory IgA and cytokine production was observed during probiotic treatment. Although probiotic bacteria can reduce some pathological processes, such as diarrhea, their ability to influence human immune function is not as clearly demonstrated. Nevertheless, it will be important to determine the optimal use of probiotics for either the prevention or treatment of diseases associated with altered immunity. Although the use of dietary probiotics has demonstrated a trend to altered immune response, the underlying mechanisms by which that occur are unclear.
Session 48, Dairy foods: More than just good nutrition
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