What is Intestinal Microbial Overgrowth Markers — Yeast/Fungal and Bacterial Dysbiosis Metabolites?
Intestinal microorganisms produce characteristic metabolites that are absorbed from the gut, metabolised, and excreted in urine as organic acids measurable by GC-MS. Arabinitol and arabinose are produced by Candida species and certain other yeasts through pentose pathway fermentation; their urinary elevation is a marker of intestinal or systemic yeast overgrowth. Dihydroxyphenylpropionic acid (DHPPA) is produced by Clostridia species through tyrosine fermentation and inhibits dopamine beta-hydroxylase — its elevation has been proposed as a marker of Clostridium overgrowth contributing to neurobehavioural symptoms through dopamine pathway interference. Tricarballylic acid is produced by Fusarium species — commonly associated with mycotoxin co-production. These microbial metabolites are absorbed through the intestinal wall and reach the kidney for urinary excretion, providing an indirect metabolic reflection of intestinal microbial population composition.