In the absence of glutamine, it will use other substances that you have in your diet.
As with everything else about candida, the whole system has to be considered. If glutamine is a deficiency in the body's tissues, then you'll have other imbalances that make the body more vulnerable to fungal candida.
Most people don't consider the complexity of the issues with candida and would rather just take this pill or that pill. The entire system should be addressed.