The volatile profile from the human body is considered to change with different disease states. This has been exploited by researchers through the use of dogs to “sniff out” and diagnose disease, particularly for cancer detection. My colleagues and I are attempting to achieve the same diagnostic capabilities as dogs, using man-made electronic nose technology. Recently we have been able to produce superior results to dogs for accurate bladder cancer diagnoses by “sniffing” urine samples.
We can also use electronic nose technology and gas chromatography–mass spectrometry for analysing breath, stool and saliva samples. The gastro-intestinal tract acts like a chemical factory producing a very wide range of volatile compounds (alcohols, ketones, esters, aromatic compounds), which to varying degrees can enter the blood stream where they can be chemically altered by the liver/other organs and then excreted by the lungs and into the urine via filtering through the kidneys. Volatiles can also be biosynthesised within the body.
Ultimately, we hope to develop rapid diagnostics that can be applied to gastro-intestinal conditions such as inflammatory bowel disease; infectious diseases of the gut, such as hospital acquired infections; and, diseases of the urinary tract, including prostate and bladder cancer, as well as infections.
The work on volatile analysis for disease diagnosis involves a transdisciplinary team of clinicians, chemists, electronics and software experts, engineers to assist in electronic nose fabrication, statisticians and microbiologists. It is always exciting – and sometimes challenging – working with such a diverse mix of experts. The solutions we have achieved from transdisciplinary collaborations have ultimately made this approach worthwhile. I look forward to sharing some more of my experience with you at the Australian Health and Medical Research Congress in Melbourne soon.