Guar gum is a water-soluble fibre obtained from the seeds of the bean-like guar plant found mostly in Pakistan and India. It is used in small amounts, but is invaluable to gluten-free baking by producing a similar effect to the product as the structure gluten usually provides. It acts as an emulsifier, thickener and stabiliser.
Guar gum is a good source of soluble fibre (which lowers cholesterol and promotes bowel regularity), and slows absorption of sugar in the small intestine, which may be helpful to diabetics. Its low digestibility gives a feeling of fullness, and the slower digestion decreases the glycemic index of the meal.