Affinity fiber, also known as functional fiber, is a type of dietary fiber that has been combined with one or more substances to provide specific health benefits. Some common synonyms for affinity fiber include prebiotic fiber, soluble fiber, and resistant starch. Prebiotic fiber is a type of affinity fiber that is selectively fermented by beneficial gut bacteria, helping to promote gut health. Soluble fiber is another type of affinity fiber that dissolves in water and helps to lower cholesterol levels and regulate blood sugar levels. Resistant starch is an affinity fiber that is not easily digested by our bodies, providing a slow and steady source of energy. Overall, affinity fiber is an important component of a healthy diet and can provide many health benefits.