KH.ORG 17 Soluble fiber can also interfere with the absorption of dietary fat and cholesterol. This helps lower lowdensity lipoprotein (LDL, or “bad”) cholesterol levels in the blood. This is one of the reasons oatmeal is often promoted as being good for heart health. “Soluble fiber can help with glucose control,” said Leslie. “If you think about the difference between white bread and whole-grain bread, Caleb Kelly, M.D., Ph.D., RD Leslie Wall, RD, LDN, CNSC the fiber in the whole-grain bread helps give it a much steadier rate of digestion and reduce spikes in blood sugar.” Soluble fiber is found in foods such as oats, barley, nuts, seeds, beans, lentils, peas, apples and blueberries. Metamucil is a common over-the-counter soluble fiber supplement. Some fiber supplements may not be appropriate for people with certain medical conditions, so if you have a condition such as celiac disease or diabetes, talk with your health care provider for guidance. Fermentable fiber Fermentable fiber is typically a subcategory of soluble fiber, but some insoluble fiber is also fermentable, meaning it can be processed by the gut’s microbiome. Although fiber passes right through the stomach and the upper part of the small intestine, it is in the large intestine that we see the added benefit of fermentable fiber. “Fiber is a nutrient that’s different from others,” said gastroenterologist and dietitian Caleb Kelly, M.D., Ph.D. “It doesn’t directly provide us with nutrition, but fermentable fiber provides nutrition to our gut microbiome. Our bodies don’t have the enzymes to break down fiber, but the microorganisms in the gut can break down fermentable fiber. This creates the production of short-chain fatty acids (SCFA), which can be used by the body as a source of nutrition and possibly even to prevent chronic diseases. For example, there is emerging research looking at how SCFA produced from fermentable fiber in the colon can regulate blood pressure in other parts of the body. SCFAs also have anti-inflammatory and anticancer properties, which may help explain why high-fiber diets are associated with lower risk of colon cancer.” Adding fiber to your diet If you are ready to begin introducing more fiber into your diet, plan to begin slowly. “The best approach to eating more fiber is to gradually increase over two weeks and drink more fluids along with the fiber,” said Leslie. “It’s similar to starting an exercise plan. Your gut needs time to adjust to the extra work it’s doing. Increasing fiber too quickly can leave you feeling bloated or give you a stomachache, so start with a small amount and increase it over a couple of weeks.” Whether you make a point of adding more fiberrich foods to your grocery list or finding a supplement that’s right for you, a small change can make a big difference in your health. Keep well A fiber-rich diet is one way to ensure colon health; another is through a screening colonoscopy. To learn more and watch an informational video about colonoscopies, visit KH.org/ gastroenterology.