Metamucil is the leading fibre supplement brand. Metamucil contains 100% natural psyllium husk, which is a great source of both soluble and insoluble fibre. Metamucil can help lower cholesterol levels. Diets low in saturated fats and cholesterol that include 7 grams of soluble fibre from psyllium husk, as in Metamucil, may lower cholesterol levels. Reduction in cholesterol levels may contribute to reducing the risk of heart disease.