Just want to throw out there that you need to look at WHO conducts the studies and with what controls, etc. There are a ton of variables to take into consideration. On paper, tons of compounds look amazing but in real life they blow.
Intravenous glutamine is okay if you're a burn victim, oral glutamine will not do an appreciable amount of "good". It's probably more beneficial for your gut than it is conducive to bodybuilding. There is a ton of glutamine in protein powders and the fools on bb.com that are obsessed with proteins and supplements are bean poles, or horribly skinny fat if they have a decent amount of size.