ABSTRACT
Ilya Ilyich Mechnikov, the Nobel Prize-winning biologist, was one of the rst scientists to promote the idea that the microorganisms in the intestinal tract could affect health and was the rst to recommend the use of benecial lactobacilli to promote long life, essentially starting the probiotics (benecial microorganisms) industry about a century ago. A Google search of the term probiotics yields 11,900,000 references. The term dysbiosis most commonly refers to an imbalance of microorganisms in the intestinal tract. A PubMed search indicates that the rst appearance of this term in its database was in 1959 and that there are now 1005 uses of the term in articles in its database. However, the acceptance of this term took many years to gain general acceptance. Fifteen years ago, a bureaucrat from one of the laboratory regulatory agencies declared that this term was not permitted to be used by the laboratory of the author and that all such references would have to be deleted. For many years, it was thought by many in the medical community that the intestinal ora was an inert passenger and of little interest to health. Even a longer time passed until the role of intestinal microorganisms in brain function and psychiatric illness began to be studied in earnest. A PubMed
Introduction ...................................................................................................................................... 31 Discovery of Clostridia Metabolites ................................................................................................ 32 Known Disease-Causing Clostridia Bacteria ................................................................................... 33 4-Cresol as an Additional Urinary Marker for Clostridium difficile ................................................ 33 Mechanism by Which Clostridia Metabolites Alter Human Neurotransmitter Metabolism and Cause Psychiatric Disorders and GI Disease ........................................................34 Metabolic Pathway for Production of Human Neurotransmitters Inhibited by Clostridia Metabolites ................................................................................................. 35 Why Elevated Dopamine Caused by Clostridia Metabolite Inhibition of Dopamine-Beta-Hydroxylase is Neurotoxic ...............................................................................36 C. difficile as a Major Cause of GI Illness ....................................................................................... 38 C. difficile Documented as a Major Cause of Depression................................................................ 38 Stool Testing as a Method for Assessing GI Clostridia Infections .................................................. 39 Origin of HPHPA and Clinical Signicance .................................................................................... 41 Treatment of Clostridia Infections ................................................................................................... 41 Examples of Organic Acid Tests of Patients with Elevated Urine Clostridia Markers in Various Neuropsychiatric Disorders ............................................................................................44 Conclusion .......................................................................................................................................44 Acknowledgments ............................................................................................................................ 45 References ........................................................................................................................................ 47
search of the terms “gut microbiota and psychiatric illness” retrieved 50 articles with the earliest published in 2008, while a search of “bacteria and psychiatric illness” retrieved 9244 articles dating back to 1947. Thus, infection was widely accepted as a potential cause of psychiatric disease and a worthy research subject, but the role of the intestinal ora in psychiatric disease was not readily accepted as a worthwhile research endeavor until recently.
