Polydextrose is a soluble fiber that is often used as a low-calorie bulking agent in food and beverage products, including protein powders. It is a synthetic compound made by combining dextrose (a simple sugar) with a small amount of sorbitol and citric acid.
In protein powders, polydextrose is often added as a low-calorie source of dietary fiber. It helps to increase the fiber content of the product without adding significant calories or affecting the taste or texture. Polydextrose also has prebiotic properties, meaning it can help promote the growth of beneficial bacteria in the gut, which may have additional health benefits.
Polydextrose is generally considered safe when used in recommended amounts.