Guar gum is a water-soluble fiber that acts as a bulk forming laxative, and as such, it is claimed to be effective in promoting regular bowel movements and relieve constipation and chronic related functional bowel ailments such as diverticulosis, Crohn's disease, colitis and irritable bowel syndrome, among others. The increased mass in the intestines stimulates the movement of waste and toxins from the system, which is particularly helpful for good colon health, because it speeds 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) that cause infective diarrhea.
Several studies have found significant decreases in human serum cholesterol levels following guar gum ingestion. These decreases are thought to be a function of its high soluble fiber content.
Guar gum has been considered of interest with regards to both weight loss and diabetic diets. It is a thermogenic substance. Moreover, its low digestibility lends its use in recipes as a filler, which can help to provide satiety, or slow the digestion of a meal, thus lowering the glycemic index of that meal. In the late 1980s, guar gum was used and heavily promoted in several weight loss products. The U.S. Food and Drug Administration eventually recalled these due to reports of esophageal blockage from insufficient fluid intake, after one brand alone caused at least 10 users to be hospitalized and a death. For this reason, guar gum is no longer approved for use in over-the-counter weight loss aids in the United States. Moreover, a meta-analysis that combined the results of 11 randomized controlled trials found that guar gum supplements were not effective in reducing body weight.
Two Japanese studies using rats showed that guar gum supports increased absorption of calcium occurring in the colon instead of in the small intestine. This means that lesser amounts of calcium may be consumed in order to obtain its recommended minimum daily intake (RDI). This has obvious implications for reduced calorie diets, since calcium rich dairy products tend to be high in calories.
However, guar gum is also capable of reducing the absorbability of dietary minerals (other than calcium), when foods and/or nutritional supplements containing them are consumed concomitantly with it. However, this is less of a concern with guar gum than with various nonsoluble dietary fibers.
Some studies have found guar gum to improve dietary glucose tolerance. Research has revealed that the water soluble fiber in it may help people with diabetes by slowing the absorption of sugars by the small intestine. Although the rate of absorption is reduced the amount of sugar absorbed is the same overall. This helps diabetic patients by lowering the amount of insulin needed to keep the blood glucose at a normal level.
It also functions as an adjuvant for diabetic drugs that are sometimes employed for the treatment of noninsulin dependent diabetes. The effect is to help lower blood glucose levels. Thus, diabetic patients who are taking drugs should consult their doctors before supplementing with guar gum.