Alternative metabolic substrate

An "alternative metabolic substrate" refers to any molecule that cells use as a source of energy or biosynthesis when the usual substrate (such as glucose) is scarce or unavailable[2][5][8]. Examples include fatty acids, amino acids, lactate, glycerol, ketone bodies, and certain sugars. Use of alternative substrates reflects the metabolic flexibility of cells and is a physiological adaptation observed in tissues under stress, starvation, or disease states—such as the shift from glucose to fatty acid oxidation in the heart during heart failure[2], or the use of glutamine and lactate in cancer cells[8]. This is a general concept in biology, not a single protein, enzyme, receptor, or therapeutic target.

Other names

alternative metabolic fuelalternative substratenon-preferred substrate