If you were in search of a new, disease-fighting antibiotic, where might you start? In a swamp? A remote island? Well, how about combing beards? Michael Mosley investigates.
On Trust Me I'm a Doctor we do experiments which sometimes throw up genuinely new science. In a previous series, for example, we discovered you can cut the calories in pasta by cooking, cooling and then reheating it.
That was a very pleasing result. But our most recent discovery, finding bacteria which appear to be producing a novel form of antibiotic, feels altogether more significant. What was particularly delightful was that they were found growing in someone's beard.
Beards, as you may have noticed, are back. The chin-strap, the goatee, the neck beard and the Van Dyke, they all have their fans. But with beards sprouting everywhere, like new grass in the spring sunshine, there has inevitably been a backlash.
Critics claim that beards are not only an irritating affectation but can potentially harbour unpleasant bugs.
So, what's the evidence that beards pose any sort of health risk? Pogonophobes, people who fear beards, had those fears confirmed by a recent study in New Mexico where they found traces of enteric bacteria, the sort usually found in faeces, in randomly sampled beards.
As one newspaper put it: '"Some beards contain more poo than a toilet."
But is this typical? A recent and rather more scientific study, carried in an American hospital, came to very different conclusions.