Our ancestors ate whole animals. Skin, cartilage, tendons, bones, organs. That meant they consumed massive amounts of glycine from collagen rich tissues. Modern humans eat almost exclusively muscle meat, which is extremely high Glycine Metabolism and Its Alterations in Obesity and Metabolic Diseases Team:Edinburgh Engineering 2021.igem.org Glycine and N acetylcysteine (NAC) are amino acidbased nutrients that serve as precursors for glutathione, one of the body's most important intracellular antioxidants. Glutathione plays a central role in reducing oxidative stress, supporting