In a study conducted at the NC Museum of Natural Sciences’ Genomics & Microbiology Lab, 18 subjects were recruited to compare what happens to bacteria under your armpits when you switch the type of underarm products you use. The subjects were divided into three groups: (1) people who used antiperspirant daily, (2) people who used deodorant daily and (3) those that did not use any underarm products. Every day of the study, both armpits were swabbed and the bacteria was analyzed.
After two days, the antiperspirant-users started to develop diverse bacteria under their arms. By the fifth day, there was significant growth of bacteria – in some cases, it was a pungent type of bacteria called Corynebacteria, the smelliest of all bacterial flora.
There are two main types of bacteria in your armpits:
Corynebacteria – The type that makes you smell
Staphlococcaceae – The least smelly bacteria