This refers to bad breath that has nothing to do with infections of the mouth, gums, or teeth. It focusses mostly on TMAU, but also refers to other cases of blood-borne bad breath as well. In case anyone wants to contact the author to find out what other "blood-borne" disorders exist, the article is written by SC Mitchell, Biological Chemistry, Biomedical Sciences, Faculty of Medicine, Imperial College London, Sir Alexander Fleming Building, South Kensington, London SW7 2AZ, UK. Tel: 44 20 7594 3180, E-mail: s.c.mitchell@imperial.ac.uk.
You might want to send an email to s.c.mitchell@imperial.ac.uk to get additional info on other diseases that could produce this, and how to test for them.