Researchers have been able to use a mix of six bacteria to eradicate Clostridium difficile infections in mice. This discovery may revolutionize how we treat C. diff, a notoriously treatment-resistant bacterium.
The most problematic part of C. diff, aside from the diarrhoea and severe bowel inflammation that can occur, is the spores released by mature bacteria. These spores are incredibly hard to eradicate and can live in the environment for years, waiting to infect another person. A small percentage of people have C. diff naturally living inside them, where competition for resources with other gut bacteria keeps it in check. But if that person takes a broad-spectrum antibiotic and kills these gut flora, C. diff experiences a population boom and serious illness arises.
Using mice infected with Strain 027 (a particularly aggressive strain responsible for several epidemics), researchers from the Wellcome Trust Sanger Institute first administered antibiotics. These didn’t work due to resistant spores remaining in the gut. Next they administered faecal transplantation – a technique where faeces from a healthy conspecific are diluted, filtered and then administered to the infected creature or person. The aim is to introduce competing microorganisms back into the gut, and as gross as it is it works in 90% of cases. Here, it successfully eradicated C. diff from the mice.
From here the researchers tested which bacteria worked best, finding in the end a combination of six bacteria – 3 of which were unknown. The mix was also highly diverse, containing bacteria from each of the four main mammal bacteria groups. If we can isolate a similar combination in humans, we will have a more precise method of treatiing C. diff – some have suggested these bacteria could be given to the patient in pill form. It would be a big improvement on faecal transplantation which works well, but runs the risk of introducing more harmful pathogens – as well as being downright disgusting.