Submitted to: Feedinfo News Service
Publication Type: Other
Publication Acceptance Date: September 12, 2007
Publication Date: October 12, 2007
Citation: Lillehoj, H.S., Lee, S.H. 2007. Dietary modulation of intestinal innate immunity using plant-derived phytochemicals. Feedinfo News Service Scientific Reviews, September. . Feedinfo News Service.
Interpretive Summary: For many mucosal diseases of poultry, including avian coccidiosis, a new paradigm is needed to develop a safe and effective disease control strategy as many current approaches are not adequate to effectively control newly emerging and re-emerging diseases. Avian coccidiosis is a major parasitic disease of substantial economic significance, estimated to cost the poultry industry greater than $700 million in annual losses in the U.S. alone. Historically, the poultry industry has relied upon prophylactic medication to limit the deleterious effects of this disease. However, the increasing governmental bans on in-feed medications and rising consumer concerns about drug residues in the food supply may eventually force the industry to eliminate this practice and develop alternative coccidiosis control strategies. A growing body of scientific evidence demonstrates the health-promoting effects of plant-derived phytochemicals, chemical compounds derived from plants or fruits. In this report, ARS scientists demonstrate the immune enhancing effect of plant-derived phytochemicals on local gut immune defenses against avian coccidiosis in poultry. The results of this study suggest that it is possible to use plant-derived phytochemicals in the modulation of gut immunity as a novel and promising control strategy for avian coccidiosis.
There is an increasing interest for developing an alternative control strategy against many infectious diseases of livestock and poultry due to much publicized concerns over the use of drugs for promoting animal health. One promising new avenue to achieve this goal is the use of natural foods and herbal products to enhance host defense against microbial infections and tumors. This approach is based on many scientific data demonstrating the immunomodulatory effects of natural and herbal products in many animal species as well as humans. Recent studies from our laboratory provided clear evidence that dietary supplements of natural phytochemicals activate innate immunity in poultry and, in particular, enhance protective immune responses against avian coccidiosis. Phytochemicals are plant- or fruit-derived chemical compounds possessing health benefits including promoting tumor killing and increased resistance to infectious diseases caused by bacteria, virus and parasites. However, very limited information is available on the mode of action of most of health-promoting plant phytochemicals. Therefore, in order to obtain a basic understanding of how dietary supplements, such as plant and fruit extracts, exert immunostimulatory effects in poultry, we carried out in vivo feeding trials using an intestinal protozoan disease model, avian coccidiosis. Our results indicated that feeding of broiler chickens with diets supplemented with crude extracts of mushroom, safflower, or plum consistently enhanced innate immunity and provided enhanced protection against live parasite challenge infection. The results of these recent studies provide clear evidence to support the notion that plant-derived phytochemicals possess immune enhancing properties in chickens and open a new avenue to develop effective strategies for disease control in poultry without using artificial chemicals.