Clostridium difficile is a nasty bacterium which causes over 10,000 infections per year in the UK alone. It leads to severe long-term diarrhoea and inflammation in the intestine and is a particular problem for the elderly and patients receiving antibiotics that wipe out their resident population of "good bacteria". What can be done about these infections? Recently, the idea of a faecal transplant, or "transpoosion" has been gaining traction. Microbiologist Brendan Wren, from the London School of Hygiene and Tropical Medicine explained the science behind the (rather unpleasant sounding) idea to Kat Arney...

Brendan - Well, it's quite an old idea from about 25 years ago. As you mentioned, Clostridium difficile is an organism that takes over the gut, when you take antibiotics and can cause severe disease and can be life-threatening. One of the problems is you get relapses over and over again. In desperate cases, because it's quite dramatic and desperate thing to do to try and re-establish the balance of your microbiota, is to have a faecal transplant. So essentially, to try to replace the bacteria that you've lost and re-establish the balance. Anecdotally, this has worked for quite a few years and more and more of these have been done worldwide and it's gaining traction as you mentioned.

Kat - Is this actually poo? I mean, let's do some details here. Sorry, if anyone's eating dinner. Is this poo? Which end does it go in and how does it work?

Brendan - It's poo so people may be able have their own or maybe their partners and more and more commonly now is the idea of poo banks around. So, within your own poo, you obviously have your own microbes and you need actually to start establish the balance. So yeah, it's literally that and it's in case in motion and it's given orally so it allows you to re-establish your gut microbiota.

Kat - This is kind of like a poo in a pill or sort of a poo shake?

Brendan - I guess more of a poo in a pill. I guess the issues with it are, you don't know what microbes you're putting in and potentially, it could be pointing some bad ones. Some countries, they do refuse to do it, but however, some patients are really desperate and Clostridium difficile can kill people. And back in 2004, 8,000 people in UK died. So, if you have a persistent problem with it, it's a desperate measure, but it's increasingly been used.

Kat - And you say it's increasingly being used, but what's the evidence that it actually works? Have there been clinical trials done of this yet?

Brendan - Some clinical trials have been done recently, but because it's such a desperate measure, it's hard to get higher enough numbers. So, it is more anecdotal. What we're interested in our research is we have a mouse model of Clostridium difficile and reinfection and we've been able to, in this day and age, as one of the speakers mentioned earlier, we can sequence quite easily so we can work out the content of the poo, and in terms of bacteria, that way, what we want to do is to get a magic cocktail if you like of bacteria that we know don't cause disease. With this cocktail, we'd be able to re-establish mark flow in a more defined approach rather than a poo pill.

Kat - Yeah, because it does sound kind of gross. I mean, we hear all the time about the adverts, the probiotics to help our healthy bacteria. Are people quite reluctant about the idea of either a poo transplant or a bacterial transplant in this kind of slightly more cleaned up way?

Brendan - What is a certain yuck factor about a poo pill but people are desperate. If it's going to save their lives, they'll do it. that's why more and more of these have been done because Clostridium difficile has tripled over the last few years in our hospitals, particularly for persistent infections then it's one possibility.

Kat - Just very briefly to wrap up, we sometimes hear about the idea that maybe you could transfer poo from different people, share your microbiome and that might change other characteristics. For example, your weight or something like that. Is there any evidence on that very briefly?

Brendan - There's not really evidence yet on that. As your previous speakers mentioned, your microbiome being associated with everything to do with diet and health cancer, etc. But we're only at the early stages and I think with the new technology and being able to sequence the work of the actual bacteria there then we have more rational approach but I'm microbiome.

Kat - So, my cunning plan to find a thin person and extract some of their poo and then eat it is not going to work for me right now.

Brendan - I wouldn't recommend it.

Kat - It does sound fantastic. Are there hopes for larger trials for this in the future?

Brendan - Yeah, for certainly in the future and particularly in the US and lots of companies are setting up in this particular area. Poo banks will be around I'm sure. You'll have not just your genome sequenced but the genomes of your gut bacteria. So, it's going to take off I'm sure.