Isoleucine also stimulates your immune system. Isoleucine: Isoleucine (isolated leucine) plays a big part in your body's muscle metabolism, energy and stress production.It is one of the three branched-chain amino acids (BCAAs). Leucine: Leucine helps your body regulate blood sugar, process protein and repair your muscles and bones.Histidine also helps your body produce histamines, a neurotransmitter that plays a role in your immune health, gastric secretion and sexual function. Histidine: Your body uses histidine to grow and repair tissues, according to the National Institutes of Health (NIH).
