Your skin is crawling with bacteria 鈥� and some of them could be protecting you from cancer.
That鈥檚 what at the University of California, San Diego and his colleagues found when they took a closer look at the friendly bacteria that makes a home on our skin.
鈥淭he human skin has almost a million bacteria per square centimetre,鈥� says Nakatsuji. Some of these are thought to have an important role in health, with some species linked to disorders like eczema.
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But some skin bacteria seem to be good for us. When Nakatsuji鈥檚 team cultured skin bacteria from volunteers, they found that many were able to produce anti-bacterial proteins when they were introduced to harmful bacteria.
A strain of one species, Staphylococcus epidermidis, also made a molecule that has a similar structure to a drug that is used to treat blood cancer. When the team applied this chemical 鈥� called 6-HAP 鈥� to a range of cancer cells it killed them.
Tumour shrinking
The team then gave mice with skin tumours injections of this chemical every 48 hours, for two weeks. Compared to mice given saline injections, 鈥渢he tumour size was suppressed by 60 per cent,鈥� says Nakatsuji.
This suggests the compound made by this S. epidermidis strain can fight tumours, but to see if the bacteria can have the same effect, the team compared it with another S. epidermidis strain that doesn鈥檛 make 6-HAP
They gave mice one of these two strains and then exposed them to enough UV light to cause skin tumours. The mice with the 6-HAP strain, however, seemed to be protected, developing around 20 per cent fewer tumours than those that had the other strain.
The results suggest that similar bacteria 鈥� which are particularly abundant on our hands and feet 鈥� may be protecting us from skin cancer, says Nakatsuji.
The team want to develop a skin probiotic that contains the strain to help treat or protect against skin cancer. It could potentially be incorporated into sunscreen, Nakatsuji says. In the meantime, he recommends avoiding harsh anti-microbial hand soaps. 鈥淵ou need to let the beneficial bacteria grow,鈥� he says.
Read more: Bad eczema flare-ups may be caused by strains of bacteria
