Guar gum also called guaran, is a galactomannan.

It acts as a stabilizer, thickener, and binder of foods. Because of its high soluble fiber content, it easily absorbs water, forming a thick, paste like substance. In fact, it has almost 8 times the water-thickening potency of cornstarch.

Guar gum helps to stabilize and add texture to foods such as ice cream, ices, cheese spreads, dressings, and some meat products. It’s used in baked goods, fruit drinks, frozen fruits, and bakery glazes. 

As a water-soluble fiber, guar gum is beneficial to gastrointestinal health, speeding the removal of waste and bacteria from the bowel and colon. In addition, because it is soluble, it is also able to absorb toxic substances (bacteria).

Guar gum also helps to lower the glycemic index of a meal by slowing the rate of digestion. It also has thermogenic, or fat-burning, activity and may be helpful in reducing cholesterol levels.

References

Martin Chaplin "Water Structure and Behavior: Guar Gum". April 2006. London South Bank University