Other Well-Known Amino Acids
Besides the 20 amino acids, there are other amino acids that are used by our bodies.
Cystine is made when two cysteine amino acids are bound together. In foods, cystine is plentiful in meats such as chicken.
Theanine is made when the amino acid glutamate is bound with ethylamine. Theanine is found in tea leaves.
Cystine and theanine boost immunity by promoting the activity of innate macrophages and natural killer (NK) cells that provide natural immunity.