Review of spray-dried plasma's impact on intestinal barrier function

Stress events have been shown to reduce intestinal barrier function (i.e., weaning, co-mingling, pathogen challenge, heat stress, etc.). Normal gut barrier function is important for maintaining nutrient absorption, while reducing exposure of the animal to toxins or pathogens that may be present in the intestinal lumen. Spray-dried plasma (SDP) is a complex mixture of functional components with biological activity independent of their nutritional value. Traditionally, SDP has been used in pig feeds at weaning because its use is associated with an increase in feed intake, growth rate, feed efficiency and reduced scours during the weaning period. In recent studies, the effects of SDP have been demonstrated in pigs at weaning (without pathogenic challenge), in pigs challenged with rotavirus, and in rats injected with a bacterial toxin. In non-challenged pigs, SDP reduced (P<0.05) macrophage numbers in the ileum while in the colon lymphocyte and lamina propria cell density was reduced. The extent and severity of diarrhea was reduced (P<0.05) when feeding SDP to pigs challenged with rotavirus. Spray-dried plasma reduced (P<0.01) dextran flux, increased expression of tight junction proteins and reduced (P<0.05) pro-inflammatory cytokines in the intestinal mucosa in rats injected with a bacterial toxin. Collectively, these findings indicate that SDP reduces intestinal inflammation and improves barrier function. Therefore, addition of SDP to animal feed helps to maintain normal intestinal barrier function and growth performance when the animal is exposed to various degrees of stress events. (C) 2010 Elsevier B.V. All rights reserved.