I eat a lot of foods high in glutamine like chicken, beef, fish, avocado and spinach, and I consume a daily protein drink, which contains approx 3-4g of glutamine. Isn’t this good enough?

Well, not really. For starters, when glutamine is taken alongside other amino acids (in food or in protein shakes), it has to compete for uptake in the body. So expecting all the benefits of glutamine to accrue whilst you ask it to duke it out with other amino acids is not realistic.

But for normal people without GI issues, glutamine through food and protein shakes may suffice.

By contrast, for those of us looking to either heal or maintain our gut health, higher doses of AND more pure sources of glutamine are needed.