Leaky gut can be caused by parasites or rogue bacteria, yeast etc. The gut becomes perforated due to the pathogens present, either they burrow themselves into the lining or the leaky gut is due to immune reactions (such as the oxidants produced by the WBCs to eliminate the pathogens.
Colostrum and vitamin A are a couple of things I can think of that will help. I would test thru Metametrix.