Xyltol is another sweetner that can cause cravings and possible blood sugar swings. My wife and I found it to upset our gut. I found it to affect the "adherence" of good bacteria---- thus the reason why it causes extreme cramping at higher doses. Xylitol is just as much anti-fungal as it is an anti-bacterial so its going to be counter productive in that department. I would rather use it as a mouth wash/toothpaste than ingest it internally.
Xylitol might be ok in small amounts for occasional use but i would use caution with it if your going to use it regularly on a long term basis. I can understand why Dr. Jeff does not recommend sweetners after the blood sugar swings and cravings that they have caused me. He refers to this as the Cephalic response and hypoglycemic cascade.
http://www.sciencedirect.com/science/article/pii/S019566630800411X
What is your view on small amounts of agave nectar. They say it has a GI index of around 35. I know coconut crystals is another sweetner that is pretty low on the GI index as well.