In order to heal leaky gut you need to reduce the inflammation of the gut. A diet that is anti-inflammatory will help this, but so will anti-inflammatory supplements such as fermented cod liver oil (or regular). Additionally, I recommend L-Glutamine to heal leaky gut, 500mg per meal.
If you eat plenty of foods that contain prebiotics (FOS) this will feed the probiotics in the gut; both heal leaky gut. Prebiotic food examples include buckwheat, teff, artichokes, onions, oat bran, etc.
Cinnamon also heals leaky gut, but beware of it because it does damage the liver as well which you need in good shape.
There’s a post awhile back that mentions leaky gut supplements: