Zym I used Perm-A-Vite by Allergy Research Group per my doctor at the time, to heal my Leaky Gut and it worked. It has a fair amount of l-Glutamine so this may help you figure out your dose.
I did pre and post testing and have also done follow-up testing. The testing isn't necessary per se, I'm just telling you that I did it out of curiosity and out of disbelief (denial) that I actually had l.g.! I had no overt GI symptoms but... indeed I did have it. Anyway, the PermAVite worked.
My doc had me on a hefty dose of this (along with a clean diet of course).
I used 2 servings (Tablespoons) twice a day for 60 days and then 1 servings twice a day for another 3 months. Less time might have worked but I just kept at it until I could do the re-test. My doc did recommend using it for at least 90 days though.
One serving/Tbs has 3.7 g L-Glutamine. 4 x 3.7 = 14.8 g total for the initial 60 days
The other ingredients are helpful though too, not just the L-Glutamine. I have several family member, friends and clients who have also used this quite successfully.
Oh and I should add that I used a ton of VSL3 along with the PermAVite.
Good luck to you
I think that higher doses (up to 20g/day) help cure acute symptoms, while lower amounts (1-5g per day) are effective for prevention. I use it to cure herpes labialis and find it extremely effective in dosages of 20-25g per day with absolutely no gut problems. I use only Glutamine manufactured by the japanese aminoacid giant Kyowa, which is thought to be one of the best manufacturers.