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why do my shirts smell if bad bacteria can't grow on cotton? why do deodorants actually work for most ppl and not for me?


Hi, that is a good question, thanks for that! On most cotton shirts, a majority of 'good' bacteria grows there. It is unfortunately much more complex than that. The microbiome also consists of  'bad' bacteria, which cause an odor. They can increase in numbers if the situation is favorable. That can be due to a number of reasons. For example: the way the fibers are assembled, the used dye, the pretreatment at the manufacturing location, the used washing detergent, or simply the microbiome that is transferred from skin to shirt. So, the 'bad' bacteria can definitely also thrive on a cotton shirt, if the 'good' bacteria are unable to grow there. Concerning your second question: most people have a dominance of 'good' bacteria in the armpit region. If somebody has a majority of odor-causing bacteria, it is difficult to get rid of them (as they also live inside the skin - see earlier). If that somebody moreover has active apocrine sweat glands, a malodor problem is the consequence. Best, Chris