Fiber is an important part of your diet. Soluble fiber swells to form a gel-like substance when it comes in contact with water. Soluble fiber supplements are used by many to improve their digestive health. Inulin and psyllium are commonly used forms of soluble fiber but they differ in many ways.
Psyllium fiber comes from the Plantago ovata plant. The plant produces up to 15,000 seeds, all of which are coated in psyllium husk. Psyllium is generally found in fiber supplements. Inulin is found in many foods, such as bananas, asparagus, onions, leeks, garlic and wheat. Inulin is extracted from chicory root and other herbs and may be used as an additive in food.
Effects on Intestinal Bacteria
The human intestines naturally contain some bacteria that do not cause infections but instead play important roles in digestion, metabolism and immunity. Substances that serve as food sources for these bacteria are known as prebiotics. Inulin is a particularly effective prebiotic, Med Herb explains, as it can be rapidly broken down by these bacteria and promotes their growth. Although in theory psyllium fiber could have similar properties, a 2008 article in the "Journal of Clinical Gastroenterology" determined that psyllium did not promote growth of intestinal bacteria.
Both inulin and psyllium are forms of soluble fiber. One of the main benefits of adding soluble fiber to your diet is that it adds bulk to stool, helping to relieve constipation. Soluble fiber absorbs excess water in your digestive tract, helping to prevent loose watery stools. Increasing your soluble fiber intake also aids in controlling your cholesterol and blood glucose levels, the University of Maryland Medical Center notes. Psyllium is more effective in these aspects because it does not get broken down by intestinal bacteria.
Both psyllium and inulin cause some gastrointestinal side effects, such as bloating, gas and nausea. This is more likely if you are not accustomed to eating a high fiber diet. When inulin is broken down by bacteria, gas forms, which exacerbates some of these symptoms. If you have trouble with inulin or psyllium, switching to the other fiber source may alleviate your symptoms.
- "Journal of Clinical Gastroenterology"; Evaluation of Prebiotic Potential of Refined Psyllium (Plantago ovata) Fiber in Healthy Women; Elli et. al.; September 2008
- University of Maryland Medical Center: Psyllium
- MedHerb.com: Inulin
- "British Journal of Nutrition"; Introducing Inulin-Like Fructans; Roberfroid Marcel; 2005.
This article reflects the views of the writer and does not necessarily reflect the views of Jillian Michaels or JillianMichaels.com.