The crossword solution for the term 'Substance in Cereals' is BRAN. BRAN is a type of cereal grain made from the hard outer layers of wheat and other grains. It is high in dietary fiber and essential fatty acids, and is often used as an ingredient in breakfast cereals, breads, and other baked goods. BRAN is also known to have a number of health benefits, including improved digestion, lower cholesterol levels, and reduced risk of certain types of cancer.