What type of fiber is known to be completely digestible?

Soluble fiber is recognized for its ability to dissolve in water, forming a gel-like substance during digestion. This characteristic aids in the absorption of nutrients and provides various health benefits, such as helping to lower cholesterol levels and regulating blood sugar. Unlike insoluble fiber, which adds bulk to stool and promotes bowel health without being digested, soluble fiber can be fermented by intestinal bacteria, resulting in short-chain fatty acids that are beneficial for gut health.

Functional fiber, while beneficial, refers specifically to fibers that have been extracted or isolated from whole foods and added to products for their health benefits, but not all functional fibers are completely digestible. Dietary fiber encompasses both soluble and insoluble fibers, making it a broader category that does not pertain specifically to digestibility. Therefore, soluble fiber is the most accurate answer when identifying a fiber type that is completely digestible due to its unique properties and health benefits.