That Armpit Odor Says a Lot About Who You Are And not just how many times a day you shower.
December 2, 2013 • By Michael White •
We, people, typically think of ourselves as people. It can be jarring to remember that we're also mammals who, like most other mammalian species, unconsciously send odor signals to each other carrying information about our gender, our health, our reproductive state, our mood, and even our potential to be a compatible mate. If the idea that your secretions say something about you creeps you out, then you won't welcome the news that the revealing scent signals we emit may actually be the end-products of microbial fermentations carried out in our bodies' damp, low-oxygen creases. A recent study of scent signals in hyenas presents the best evidence to date that bacteria are responsible for producing pheromones in a mammalian species. The implication of these results is that the bacteria in our underarms may have a surprisingly complex role in our social lives.
That microbes are actually the makers of mammalian pheromones is an idea that dates back to the 1970s when several scientists proposed the "fermentation hypothesis." Their idea was that, because scent glands are typically found in warm, damp, low-oxygen areas of the body, microbes that thrive in those areas ferment the body's nutrient-rich secretions into the odorous chemical signals used by most mammals to communicate.