HPHPA stands for 3-(3-hydroxyphenyl)-3-hydroxypropionic acid.
The source of this compound appears to be multiple species of anaerobic bacteria of the Clostridium genus.
The biochemical role of Clostridia in altering brain neurotransmitters is due to the fact that Clostridia metabolites inactivate dopamine beta-hydroxylase, leading to an excess production of brain dopamine and reduced levels of the neurotransmitter norepinephrine. Excess dopamine is associated with abnormal or psychotic behavior. This imbalance can be demonstrated in the Organic Acids Urine Test by observing the ratio of the major dopamine metabolite, homovanillic acid (HVA), to that of the major norepinephrine metabolite, vanillylmandelic acid (VMA) when the Clostridia marker HPHPA is elevated.
The highest value of HPHPA was measured in the urine of a young woman with first onset of schizophrenia. Treatment of Clostridia bacteria resulted in loss of auditory hallucinations. In autism, children with gastrointestinal Clostridia commonly exhibit aggressive behavior, agitation, obsessive compulsive behavior, and irritability. They may have very foul stools with diarrhea with mucus in the stools although some individuals may be constipated. Stool testing for Clostridia is usually of limited usefulness since most Clostridia species are considered probiotics or beneficial. There are about 100 species of Clostridia that are commonly found in the gastrointestinal tract. Only seven of these species are producers of HPHPA including C. sporogenes, C.botulinum, C. caloritolerans, C. angenoti, C. ghoni, C.bifermentans, C. difficile, and C. sordellii while C. tetani,C. sticklandii, C. lituseburense, C. subterminale, C.putifaciens, C. propionicum, C. malenomenatum, C.limosum, C. lentoputrescens, C. tetanomorphum, C.coclearium, C. histolyticum, C. aminovalericum, and C.sporospheroides do not produce compounds that are converted to HPHPA.
References:
- https://www.ncbi.nlm.nih.gov/pubmed/20423563
- https://www.tandfonline.com/doi/abs/10.1179/147683010X12611460763968
HPHPA (3-(3-hydroxyphenyl)-3-hydroxypropionic acid)
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