I'm no doctor or naturopath, but I think the l-glutamine heals the gut by forcing the holes to shrink. I think the yeast loses it's grip during this process.
I recommend you try a different probiotic. The one that ultimately worked for me is HMF Neuro. Look it up. There is a human strain in there. Does that make all the difference? I can't say 100% but that is the only thing I'm taking this month and my gut is definitely healing. yeast in my stool, tongue clearing, die-off coming and going.
Still on low Sugar and gluten-free diet too but as far as supplementing..thats the only thing I'm doing.