Human Body Odors

I have been studying malodours and Caucasian adult axillaries odor for many years. This axillary odor is made of 3 main chemicals: acids, sulfur compounds and steroids. I have discovered the sulfur compound responsible for the onion odor in human sweat. Aprocrine glands excrete compounds which don’t smell ( = odor precursors) and it is the metabolic products from the microflora on the skin which release the malodor. I discovered the precursors of the sulfur compounds and the precursors of steroids. The quality of the microflora (microbiome) is critical in malodor formation. I also demonstrated in collaboration with a team of sensory scientists and microbiologists, that two subjects excreting the same amount of precursors but with different microflora have either a strong odor or almost no odor. Together with partners in academia, I also addressed others odor questions. Human milk secretion shows several parallels to sweat production. For example, does human milk contain sweat specific substances? Does the presence of human sweat specific substances drive Anopheles gambiae mosquito (the main vector of malaria) to seek a human host?

 Toilet Malodors

I have been working with the Bill & Melinda Gates Foundation to understand and help to control malodors from a range of sanitation systems. I conducted field research in India and some African countries such as Kenya, South Africa and Uganda where toilet malodors were sampled and analyzed. A sensory survey was organized to understand cultural perception of these malodors. As part of a multidisciplinary team, prototypes were developed to control malodors. Having access to descent sanitation should be a basic human right, but having work is necessary to break poverty. Upcycling human fecal biochar as a perfume delivery system is an example how we can add value to a waste to achieve a circular economy.

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