Imagine a world without body odor. Some recent discoveries by scientists in this surprisingly under-researched area may help us get there.
Armpit secretions begin their life odorless. It takes bacteria to give them their pungent tang.
Two types of chemicals are mainly responsible. One is the fatty acid, butyric acid. You may not have heard of butyric acid but you've probably smelled it. It's present in large amounts in cheeses such as blue, limburger and aged parmesan. It's even in milder cheeses like Swiss, though in much smaller amounts.
But armpit odor doesn't smell like cheese. It's the second type of chemical, sulfur-containing thioalcohols, that is the most pungent and main contributor to that odious armpit smell. Only a few types of the bacteria that live in our armpits produce them, and researchers from the Universities of York and St. Andrews have now found out how they do so, isolating and purifying the responsible enzyme.
They've even been able to place this enzyme into bacteria that don't normally produce it and turn them into odor producers. That's not likely to win the resarchers any public accolades, but it does show that they're working with the right material.
Two types of chemicals are responsible for body odor. One, butyric acid, is present in large amounts in blue, limburger and aged parmesan cheese.
Like the human gut, the underarm is home to a wide variety of bacteria, its microbiome. Only a few types produce odor-causing chemicals — the article lists six, all of which are types of Staphylococcus. Having discovered the enzyme that's responsible, the researchers hope to come up with a targeted inhibitor, another chemical that will prevent the enzyme from doing its dirty work while leaving the rest of the underarm microbiome unaffected.
It's also possible that something like an underarm probiotic could be developed, one that would replace the offending bacteria with others that don't produce the chemicals that lead to armpit odor. This is a riskier approach because the offensive bacteria may offer some benefit to their human hosts. It may be hard to think of any, but it's certainly likely that they once did, according to the researchers.
There's evidence that the odor-causing bacteria split off from other Staphylococci about 60 million years ago, well before there were any people. Presumably it's been with apes and then with humans ever since. When two species are associated with each other for that long, it's usually because it benefits both of them. A pungent odor might have come in handy on a coordinated hunting exposition, helping budding humans locate each other before speech was common. And while there doesn't seem to be any advantage to smelling bad today, other than to accelerate speed dating, it's possible that there actually is one.