Which statement about soluble fiber is true?

• A. It dissolves in water and can reduce cholesterol and improve glycemic control.
• B. It is not fermentable by gut bacteria.
• C. It adds bulk to stool and supports bowel regularity.
• D. It provides more calories per gram than fat.

Answer: (A)

Soluble fiber dissolves in water to form a gel-like substance that slows digestion. This gel helps reduce LDL cholesterol by binding bile acids and cholesterol in the gut, which lowers their reabsorption and shifts the liver’s cholesterol metabolism. It also slows the rate at which glucose is absorbed, improving glycemic control after meals. In addition, soluble fiber is fermentable by gut bacteria, producing short-chain fatty acids that can have further metabolic benefits. The idea that soluble fiber primarily adds bulk to stool reflects more what insoluble fiber does; soluble fiber’s main effects aren’t about increasing stool mass. And fiber provides few calories—far less than fat—since most of its energy comes only from limited fermentation. So the statement that soluble fiber dissolves in water and can reduce cholesterol and improve glycemic control is the true one.