What kind of fiber is available in the market?
Sue Mikolaitis: Fiber comes from a variety of foods and dietary supplements and is essential to maintaining the health of your gastrointestinal tract. There are two main types of fiber, soluble and insoluble. Solubility refers to how well the fiber dissolves in water and how fermentable it is in the colon. Soluble fiber is highly fermentable by colonic bacteria, whereas insoluble fiber can be fermentable or non-fermentable. Soluble fiber can be viscous (such as oats and legumes) or non-viscous (such as wheat bran and whole grains), but all insoluble fiber is non-viscous. The viscosity and the solubility give each fiber its unique characteristics. Generally, the highly fermentable soluble fibers promote lowered cholesterol, addition of beneficial bacteria to the colon, and other significant health effects. Insoluble fiber increases stool bulk, decreases stool transit time, and softens the stool. Currently it is recommended that persons with irritable bowel syndrome (IBS) increase their soluble fiber intake.
Nearly all foods can provide some fiber, with the exception of complete proteins such as meat, poultry, fish, milk, eggs, and cheese and fats such as butter and oil. Vegetables, fruits, whole grains, nuts, beans, legumes, and seeds provide the majority of fiber in our diets. Of these foods, most provide both types of fiber, but here are lists of foods that are high in soluble or insoluble fiber.
Foods with Soluble Fiber:
Oat-based products, barley, peas or pea-starch products, legumes (beans and lentils), apples, pear, peaches, nectarines, oranges, grapefruit, other citrus fruits, prunes, passion fruit, amaranth, carrots, flaxseed and jicama (Mexican potato).
Foods with Insoluble Fiber:
Whole-wheat based products, wheat bran or shredded wheat, nuts, quinoa, seeds, popcorn, vegetables, rice bran and brown rice, fruits, especially the skin and berries.
See below the list of supplement name (with their ingredients in the parenthesis) that can be used to increase fiber.
Viscous Soluble Fiber Supplements:
Konsyl® (psyllium), Metamucil® (psyllium), Acacia Tummy Fiber® (acacia gum),Citrucel® (methylcellulose), qualactin® (calcium polycarbophil) and FiberCon® (calcium polycarbophil).
Other products that also contain psyllium include: Alramucil®, Cilium®, Fiber Eze®, Fiberall®, Genfiber®, Hydrocil®, Konsyl-Orange®, Maalox Daily Fiber Therapy®, Modane Bulk®, Perdiem Fiber®, Reguloid, Serutan®, Syllact®, V-Lax®, and Fybogel®.
Non-Viscous Soluble Fiber Supplements:
Benefiber® (wheat dextrin), Fibersure® (inulin), FiberChoice® (inulin), Nutraflora® (short-chain fructooligosaccharides), Oat bran (beta-glucan) and Unifiber® (cellulose).
Insoluble Fiber Supplements:
Wheat bran, raw bran, wheat germ and rice bran.
The list of fiber products available is not limited to the list above. In fact, there are numerous other brand names that provide fiber material and contain one or a mixture of several ingredients mentioned above. This list includes:
SteviaPlus Fiber®, Dental Fibers®, Everybody‘s Fiber®, Fiber Delights®, Fiber Perfect®, Gentle Fibers®, Fiber Force-6®, Multi-Fiber®, Natural Fiber®, Fiber Max®, Daily Fiber®, Chewable Fiber®, Colonix Fiber®, Fiber Plus Caps®, Metamucil Psyllium Fiber Wafers®, Fiber Clean Capsules®, Fiber Fusion®, Everyday Fiber System®, Daily Fiber X®, Daily Fiber®, Activated Fiber Tablets®, Super Fiber Psyllium Seed®, Multi-Fiber Complex®, Daily Fiber Powder®, Super Seed®, Beyond Fiber®, Thermo-Bond Fiber Tablets®, Brewer‘s Yeast Plus Fiber®, and Fiber Choice Fiber®.
The recommended intake of fiber is 25 to 35 grams per day or 14 grams per 1000 calories consumed, according to the 2005 Dietary Guidelines for Americans. Side effects of increasing fiber too quickly include gas and bloating. It is best to slowly increase your fiber by 1–2 grams every other day, consistently, until you reach the recommended amount. The same is true of fiber supplements, so start with less than the instructed recommended dose. In order to improve tolerance but decrease gas, consider using Beano® when you eat fiber-containing foods or simethicone such as Gas-X® or Phazyme® to minimize the possibility of side effects. Eat foods that are good sources of natural fiber, as food provides additional vitamins and minerals that supplements do not.
Furthermore, many fiber supplements have additives, flavorings, colorings, and preservatives. Because some people with IBS are sensitive to these ingredients, you may want to choose a supplement with as few of these additives as possible. In particular, the alcohol sugar sorbitol is found in chewable fiber supplements and should be avoided by people with gastrointestinal issues. Seek further advice from your gastroenterologist or registered dietitian regarding your fiber needs and the best way to incorporate fiber into your diet.