Dont buy normal glutamine. Almost no one cured stories with that normal item. People here always try glutamine and fail or they need something else along with it. Read the link I posted or just google micronized glutamine leaky gut. For some reason, it seems this micronized version of glutamine works wonders for leaky gut. There is also a review in amazon about it curing the leaky gut of another person.
Another supplement you should really consider its N-Acetyl-Glucosamine. Im sure taking those two together should solve the leaky gut in months UNLESS its caused by parasites. In that case at least it should help repair the damage in a daily basis but you would never reach the cured stage.