Quirks and Quarks

Bacteria turns poop blue when you're sick

Bacteria in the gut of mice are engineered to diagnose inflammation by turning an enzyme in their poop blue.
Engineered bacteria in mice turn blue when inflammation has been diagnosed. (Wyss Institute and Harvard Medical School)

Bacteria can be engineered to perform various tasks.  For example bacteria has been engineered to make valuable proteins for medical use, and to make enzymes that are used to help degrade toxic chemicals when spills occur.

But a new study by Dr. David Riglar from the Department of Systems Biology at Harvard Medical School in Boston has engineered bacteria in the gut of mice for diagnostic purposes

The bacteria can remain in the gut of the mice for up to six months and can detect a molecule associated with a particular illness, in this case inflammation.

When a fecal sample is analyzed for the molecule, the bacteria has also been designed to turn blue if the inflammation is present. 

It is hoped that this technique can be applied to the detection of inflammatory illnesses like Irritable Bowel Syndrome or Crohn's Disease in humans, and possibly used as an early warning sentinel of other diseases at some point, including cancer.