Introduction Heavy exercise causes gut symptoms and, in extreme cases, “heat stroke” due to increased intestinal permeability of luminal toxins. We examined whether zinc carnosine (ZnC) a health food product taken alone or in combination with bovine colostrum, a natural source of growth factors, moderated such effects.

Methods 8 volunteers completed a four-arm double-blind, placebo-controlled, crossover protocol (14 days placebo, ZnC, colostrum, ZnC + colostrum) prior to standardised exercise undertaken 2 and 14 days after starting treatment. Changes in epithelial resistance, apoptosis signalling molecules and tight junction protein phosphorylation in response to 2⁰ C rise were determined using Caco-2 & HT29 intestinal cells.

Results Body temperature increased 2⁰ C and gut permeability (5 h urinary lactulose:rhamnose ratios) increased 3 fold following exercise (0.32 ± 0.016 baseline to 1.0 ± 0.017 at +14 days, p < 0.01). ZnC or colostrum truncated rise by 70% after 14 days treatment. Combination treatment gave additional benefit and truncated exercise induced increase at +2 day (30% reduction, p < 0.01)

2°C temperature rise in in vitro studies caused doubling of apoptosis and reduced epithelial resistance 3–4 fold. ZnC or colostrum truncated these effects (35–50%) with greatest response seen with combination treatment (all p < 0.01). Mechanisms of action included increasing HSP70 and truncating temperature-induced changes in Baxα and Bcl-2. ZnC also increased total occludin and reduced pTyr-claudin, pTyr-occludin and pSer-occludin, enhancing tight junction formation and stabilisation.

Conclusion ZnC taken alone or with colostrum increased epithelial resistance and tight junction structure and may have value for athletes and preventing heat stroke in military personnel.

Disclosure of Interest None Declared