Two questions - why do men sweat more fatty substances? Also a question about hand washing+microbiome

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Hi, you said that men tend to have more Corynebacteria because they have thicker skin and sweat more fatty substances. Why do they sweat more fatty substances? Does it have a purpose or is it just, like, an evolutionary side-effect of something, like appendixes or wonky teeth or something? Also, in science class one time, we grew samples from bacterial swabs collected from our hands. Everyone had different bacterial colonies/fungi with different colours etc., but my petri dish had nothing except for these little pale greyish-yellow dots (I googled them and I think they might be Staphylococcus; they looked like this: Anyway, at the time I washed my hands a LOT every day, probably more than was healthy, so I was wondering, would that have been the reason my microbiome on my hand had so little diversity? Thank you!