Humans are disgusting – we’re constantly shedding skin cells, oozing skin oils and secreting sweat onto everything we’re wearing. In fact, a human sheds about 500 million skin cells, and a litre of sweat, every day.

On their own, those things don’t actually smell too bad. The problem starts when the bacteria living on your skin get involved. They live by feasting on your sweat and skin oils, breaking the proteins in those down into smelly by-products.

For example, the Staphylococcus epidermidis bacteria, which lives on your skin, breaks amino acids in your sweat down into stinky isovaleric acid. That’s the same acid that also pops up in strong cheese and in badly made beer. But it’s apocrine sweat that really makes you stinky. Apocrine sweat glands are found in the genital area, breasts, armpits and, randomly, your eyelids.

So given this festering zoo on your body, which clothes should you wash regularly, and which are less important? What about towels… or trousers? Greg Foot from the BBC Youtube channel Britlab explains:

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