Indican (indoxyl sulfate) is a putrefaction product resulting from bacterial deconjugation of tryptophan in the small intestine. Indican is water soluble and excreted through urine. Increases in urine indican can indicate protein maldigestion or malabsortion, or the overgrowth of gut anaerobic bacteria. Indican levels in urine can also increase in response to a high protein diet.
