Influence of 4 weeks of bovine colostrum supplementation on neutrophil and mucosal immune responses to prolonged cycling

Bovine colostrum (COL) has been advocated as a nutritional countermeasure to exercise-induced immune dysfunction. The aims of this study were to identify the effects of 4 weeks of COL supplementation on neutrophil responses and mucosal immunity following prolonged exercise. In a randomized double-blind, parallel group design, participants [age 28±8 years; body mass 79±7kg; height 182±6cm; maximal oxygen uptake ( V ˙ O 2 m a x ) 55±9mL/kg/min] were assigned to 20g per day of COL (n=10) or an isoenergetic/isomacronutrient placebo (PLA; n=10) for 4 weeks. Venous blood and unstimulated saliva samples were obtained before and after 2.5h of cycling at 15% Δ (∼55-60% V ˙ O 2 m a x ). A significantly greater formyl-methionyl-leucyl phenylalanine-stimulated oxidative burst was observed in the COL group compared with PLA group (P<0.05) and a trend toward a time×group interaction (P=0.06). However, there was no effect of COL on leukocyte trafficking, phorbol-12-myristate-13-acetate-stimulated oxidative burst, bacterial-stimulated neutrophil degranulation, salivary secretory IgA, lactoferrin or lysozyme (P>0.05). These findings provide further evidence of the beneficial effects of COL on receptor-mediated stimulation of neutrophil oxidative burst in a model of exercise-induced immune dysfunction.