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Milk contains numerous bioactive substances including immunoglobulins, cytokines, growth factors and components possessing antibiotic and prebiotic activity. Such compounds may be important to protect the immature intestine in preterm piglets from harmful inflammatory reactions involved in disorders like necrotising enterocolitis (NEC). It was hypothesised that bovine colostrum and milk formulas enriched with sialic acids (SL), gangliosides (Gang) or osteopontin (OPN) would improve gastrointestinal function and NEC resistance in preterm piglets. Furthermore, the immunomodulatory activity of the enriched milk fractions was investigated in vitro using dendritic cells (DC) stimulated with gut-associated bacteria. Forty-seven preterm piglets (Large White x Danish Landrace) from three litters were delivered by caesarean section at 105 day of gestation. Animals were given total parenteral nutrition (TPN) through arterial catheter for 2d followed by enteral feeding for 1.5d. In experiment 1 (N = 26), a control formula was compared with an OPN-enriched formula, while experiment 2 (N = 21) compared a control formula with bovine colostrum or formulas enriched with Gang or SL.
The OPN enrichment decreased NEC severity relative to control formula (P<0.01), without any significant effects on NEC incidence, digestive enzyme activities and hexose absorption. Neither SL- nor Gang-enriched formulas improved NEC resistance or digestive functions, while all the intestinal functional parameters were significantly improved in pigs fed bovine colostrum, relative to formula. The effects in vivo were supported in vitro by bacteria- and dose-dependent modulation by colostrum whey of the cytokine response from bacteria-stimulated murine bone marrow-derived DC. It is concluded that OPN had only moderate NEC-protective effects, while formulas enriched with Gang or SL were ineffective.
The observed modulation of DC cytokine response by bovine colostrum whey in vitro may be due to a synergistic action of various milk bioactives, and it may explain its beneficial effects on NEC development and intestinal function in a piglet.
HK Møller, T Thymann, LN Fink, H Frokiaer, AS Kvistgaard and PT Sangild. Bovine calostrum is superior to enriched formulas in stimulating intestinal function and necrotizing enterocolitis resistance in preterm pigs. 2011. British Journal of Nutrition, 105: 44-53.
