The main thing that feeds foot smell is sweat. With more than 250,000 sweat glands each, your feet are among the most perspiring parts of the body.
In one day, each foot can produce more than a pint of sweat! Sweat is basically just salt and water, though, so it doesn't have a distinctive smell of its own.
The smell is actually caused by bacteria on our skin that eats the sweat and excretes waste that has a strong odor. It's perfectly normal to have bacteria on your skin, and it doesn't ordinarily produce a noticeable smell, but sweat attracts bacteria and gives them a whole lot to feed on.
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