Elucidation of chemical compounds responsible for foot malodour

Short-chain fatty acids from the socks and feet of subjects either with strong foot odour or with weak or no foot odour were extracted with ethyl ether, and then analysed by gas chromatography/mass spectrometry (GC/MS). Short chain fatty acids were found in greater amounts from those subjects with strong foot odour. Iso-valeric acid was present in all the subjects with foot odour but was not detected in those without. Olfactory evaluations of the various short-chain fatty acid solutions were in agreement with the GC/MS analyses. By incubating sweat and lipid from subjects with strong foot odour, we succeeded in reproducing the foot malodour. GC/MS analyses of reproduced foot odour revealed that short-chain fatty acids were present in a similar composition to that found in vivo.