Within the brain, there are relationships between signal molecules that mediate important higher functions such as memory, learning, behaviors, and emotional states, which can be problematic in autism, and amino acids. Because many signaling molecules are synthesized from various amino acids. So, some amino acids lead to the synthesis of effective signaling molecules in the brain. For example, serotonin (5-hydroxytryptamine; 5-HT) is synthesized from the amino acid tryptophan, and then melatonin is synthesized from it.

Being an essential amino acid, phenylalanine leads the synthesis sequence of tyrosine, L-Dopa, dopamine, norepinephrine (noradrenaline), and epinephrine (adrenaline).

From this, the following conclusion can be drawn: To alleviate and reduce some of the problems seen in autism, it is necessary to maintain the balance of neurotransmitter molecules in the brain. In order to achieve this balance, it is important to maintain equilibrium in the metabolism and quantity of amino acids that lead to the synthesis of signaling molecules.

A holistic medical approach to autism is definitely beneficial.

The synthesis of signal transmission molecules from precursor amino acids and their relationship with the microbiota is presented in the table below (*)

*Clinical Neurotherapy DOi: http://dx.doi.org/10.10.16/B978-0-12-396988-0.00014-3