Some methods of processing the raw fiber may break up its carbohydrate strands, weakening the gel. That means that you really have to test each soluble fiber product to make sure it works effectively. A search through the medical literature turned up only two brands with good, published research showing that they can lower cholesterol. While it has been approved for sale only as a laxative, Metamucil also seems to lower cholesterol. There's a downside, though.
Some people are allergic to psyllium.
In rare cases, it sends people into life-threatening anaphylactic shock. But to get ten grams of psyllium you'd have to eat almost three servings. The company has asked the FDA for permission to make a health claim that foods with psyllium can help lower cholesterol. Fiber Plan, from Shaklee Corporation, is a mixture of the soluble fibers psyllium, pectin, guar gum, and locust bean gum. In two good studies, Fiber Plan lowered cholesterol.