Inhibition of the Beta-oxidation Pathway of Fatty Acids and Dopamine- Beta-hydroxylase by Phenyl Derivatives of Short- Chain Fatty Acids from Gastrointestinal Clostridia Bacteria is a (the) Major Cause of Autism.

Abstract

Background: A The author's comprehensive evaluation of the biochemical metabolomic literature over more than 40 years discusses multiple studies documenting abnormal elevations of the neurotransmitter dopamine and its metabolites as well as inhibitors of dopamine beta hydroxylase (DBH) from Clostridia bacteria in urine samples and cerebrospinal fluid samples of children with autism.

Aims of review: The evaluation intends to elucidate the reasons for the elevation of dopamine and its metabolites in urine and their relationship to increased Clostridia colonization of the gastrointestinal tract in children with autism. In addition, to the evaluation of Clostridia metabolism and its effects on abnormal dopamine metabolism in autism, a secondary aim intends to demonstrate as a hypothesis that one particular metabolite of Clostridia bacteria-3-hydroxy-(3-hydroxyphenyl)- 3-hydroxypropionic acid (HPHPA)-may cause even more severe effects on in autism than other metabolites by leading to depletion of free coenzyme A (CoASH). This depletion of free Coenzyme A leads to a deficiency of cholesterol and activated palmitic acid needed for activation of the key brain developmental protein sonic hedgehog, which has recently been research has shown to be severely abnormal in severe autism.

Key scientific concepts of review: Laboratories throughout the world have consistently found high quantities of HPHPA and 4-cresol in high percentages of urine samples of children with autism. Those inhibitors, which intestinal Clostridia bacteria produce, cause an elevation in dopamine and its metabolites, which affect the brain's and the sympathetic nervous system's key enzyme dopamine-beta-hydroxylase (DBH). Excessive dopamine and its toxic metabolites due to these DBH inhibitors may cause brain damage due to excessive unstable dopamine quinones, toxic adducts of dopamine disrupting brain mitochondrial energy production, and oxygen superoxide. HPHPA, a short chain phenyl compound, may have additional biochemical effects on the brain in autism, causing a reduction in free CoASH needed to produce the CoA palmitic acid derivative necessary to activate the key brain developmental protein sonic hedgehog. The depletion of CoASH appears to be a new therapeutic target to reverse the adverse effects of the HPHPA metabolite on the beta oxidation of fatty acids and cholesterol synthesis that are prevalent in autism.

Conclusions: Variations in the severity of autism could be based on the types and concentrations of the Clostridia markers produced and the extent to which these markers, such as HPHPA, have depleted critical lipids, such as cholesterol and CoA palmitic acid derivative. Patients need those lipids for the activation of the developmental protein sonic hedgehog. In addition, the sequestration of coenzyme A by short chain adducts of Clostridia leads to the depletion of critical free CoASH, needed throughout intermediary metabolism, and creates a biochemical storm that especially affects brain function.