The effect of bovine colostrum supplementation on intestinal injury and circulating intestinal bacterial DNA following exercise in the heat

Purpose: Exercise-induced changes in intestinal permeability are exacerbated in the heat. The aim of this study was to determine the effect of 14 days of bovine colostrum (Col) supplementation on intestinal cell damage (plasma intestinal fatty acid-binding protein, I-FABP) and bacterial translocation (plasma bacterial DNA) following exercise in the heat. Methods: In a double-blind, placebo-controlled, crossover design, 12 males completed two experimental arms (14 days of 20 g/day supplementation with Col or placebo, Plac) consisting of 60 min treadmill running at 70% maximal aerobic capacity (30 °C, 60% relative humidity). Blood samples were collected pre-exercise (Pre-Ex), post-exercise (Post-Ex) and 1 h post-exercise (1 h Post-Ex) to determine plasma I-FABP concentration, and bacterial DNA (for an abundant gut species, Bacteroides). Results: Two-way repeated measures ANOVA revealed an arm×time interaction for I-FABP (P=0.005, with greater PostEx increase in Plac than Col, P=0.01: Plac 407±194% of Pre-Ex vs Col, 311±134%) and 1 h Post-Ex (P=0.036: Plac 265±80% of Pre-Ex vs Col, 229±56%). There was no interaction (P=0.904) but there was a main effect of arm (P=0.046) for plasma Bacteroides/total bacterial DNA, with lower overall levels evident in Col. Conclusion: This is the first investigation to demonstrate that Col can be effective at reducing intestinal injury following exercise in the heat, but exercise responses (temporal pattern) of bacterial DNA were not influenced by Col (although overall levels may be lower).