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The chemical culprit behind body odour has been identified, scientists reported in 2020. 

An enzyme made by bacteria which reside in human armpits has been found to produce the pungent scent we know as BO. 

Dubbed the ‘BO enzyme’, it is made by bacteria called Staphylococcus hominis which humans inherited from our now-extinct ancient ancestors. 

Researchers from the University of York worked with Unilever and discovered body odour has likely plagued Homo sapiens since we first evolved. 

We inherited it from our more primitive predecessors and now the smelly bacteria call our armpits home.   

Dr Gordon James, of Unilever, says: ‘This research was a real eye-opener.

‘It was fascinating to discover that a key odour-forming enzyme exists in only a select few armpit bacteria – and evolved there tens of millions of years ago.’

By identifying the specific odorous compound, academics believe they can create deodorants that neutralise the enzyme, eradicating BO. 

Dr Michelle Rudden, from the University of York’s Department of Biology, said: ‘Solving the structure of this “BO enzyme” has allowed us to pinpoint the molecular step inside certain bacteria that makes the odour molecules.

‘This is a key advancement in understanding how body odour works, and will enable the development of targeted inhibitors that stop BO production at source without disrupting the armpit microbiome.’ 

The enzymes produced by the bacteria latch onto odourless compounds made by the body’s apocrine glands. 

These are in the skin and produce sweat and open into hair follicles. They are only found under the arm, around the nipple and external genitalia. 

Human’s also have eccrine glands which are all over the body and do not open into hair follicles. 

While eccrine glands are known to be useful in thermoregulation, little is known about the hairy apocrine glands except that they are smelly and hairy. 

Scientists know bacteria live there and this microbiota is essential to their functionality. 

The study, published in the journal Scientific Reports, found odourless precursor chemicals secreted from the glands are sliced up by the enzyme.

This transforms the harmless, odour-free chemicals into a thioalcohols, which the researchers describe as ‘most pungent volatiles’ in sweat despite being found only in trace levels.