Guar gum is often used together with xanthan in gluten free recipes to improve elasticity of doughs 
Guar gum has almost 8 times the thickening power of corn starch and about 16 times the thickening 
power of flour. To a gluten free flour mixture without gums add 0.5% guar when used for cookies; 1.0% when used for cakes, muffins or quick bread; and 2.0% when the flour is to be used for bread/pizza