Not all poo is created equal: Scientists discover super donors for fecal transplants

A new study, led by researchers from the University of Auckland, has described the phenomenon of "super donors," people who contribute stool samples for use in trials whose poop seems to be significantly more effective in leading to clinical improvements for fecal transplant subjects.

Despite a long history of anecdotal use, the science behind fecal transplantation is still in its infancy. Altering a person's gut microbiome via a fecal transplant has proved mildly successful across a variety of different trials, but results have proved frustratingly inconsistent.

The mixed results have led some researchers to try to understand whether there are particular fecal donors whose poop is more effective than others. A new study has investigated this "super-donor" phenomenon, suggesting that it does indeed exist.

"We see transplants from super-donors achieve clinical remission rates of perhaps double the remaining average," says Justin O'Sullivan, senior author on the new study. "Our hope is that if we can discover how this happens, then we can improve the success of fecal transplantation and even trial it for new microbiome-associated conditions like Alzheimer's, multiple sclerosis and asthma."

Homing in on exactly what specifically constitutes super poo has presented a complicated challenge for researchers. One of the most fundamentally significant features of good donor stool seems to be a broad microbial diversity – the larger the variety of species in the stool, the more effective the outcome when delivered via fecal transplant. The study also suggests high levels of what are referred to as "keystone species" are important in the efficacy of a fecal transplant.