If you are thinking of incorporating it because of that article that shows it has the potential to help with treatments - then they are using the same things we use over the counter for sweetening things. If your grocery store doesn't have it, a health food store will or you can order it online.
But, a word of caution - they never gave the amounts used, or revealed which brand produced which results, and with Lyme, what is often effective in a test tube isn't effective in the body. And this experiment was done in the test tube.
There was a conversation on this very subject yesterday. You can find it here:
www.healingwell.com/community/default.aspx?f=30&m=3630965