Is Bad Breath a Sign of Liver Disease? - Chromatography Investigates

We all know someone with bad breath - halitosis to give it its proper name. It can be temporary - the result of a dodgy food choice, not drinking enough water or simply just needing to go to the toilet. Some people suffer more than others, and some people are more sensitive to the smell of bad breath. For many people, a good drink of water and a brush of the teeth and tongue are all it takes to fix the issue.

But for some people, halitosis can be indicative of something more sinister. A recent paper published in the Journal of Chromatography B used gas chromatography and mass spectrometry (GC-MS) to see if odour compounds in breath could be indicative of liver disease. Chromatography is a versatile analytical technique that separates and analyses individual compounds in a sample. By adjusting the column parameters, different compounds can be analysed - an idea discussed in the article Using Different HPLC Column Chemistries To Maximise Selectivity For Method Development.

More than just a dirty mouth?

There are several medical conditions that can leave some patients with dodgy breath. Some types of diabetes can cause a ‘sweet acetone’ odour, whilst kidney failure results in some people having ‘fishy breath’. It has been suggested that these odours are the result of volatile organic chemicals (VOCs) being released by the patients suffering the condition. So now, researchers are working to see if the VOCs in exhaled air could be used as a non-invasive method of helping a doctor diagnose diseases.

Liver disease is one disease that researchers are looking at to see if bad breath can help. The usual symptoms of liver disease include jaundice, chronic fatigue and abdominal pain, but researchers think there might be an odorous component too. It has been reported that patients with liver disease: ‘may acquire a sweet, musty or slightly fecal aroma of the breath, termed fetor hepaticus, which has been mainly attributed to sulfur compounds.’ This is caused by metabolites - that are normally processed in the liver - increasing in the body and entering the circulation. Some of the compounds are then exhaled.

Chromatography breathalysing the liver

The researchers sampled over 100 patients - 52 with liver disease - using sorbent tubes to capture the VOCs in their exhaled air. The samples were analysed using thermal desorption followed by GC-MS. Air samples taken from the sample room were used to subtract any compounds that might have been present in the background.

The study found several compounds including dimethyl sulphide, acetone, 2-pentanone and 2-butanone were higher in patients with liver disease compared with the control patients who were free of disease. They state that these compounds are likely to cause a smell on the breath of the patients. A breakthrough in the identification of liver disease? Don't hold your breath.