Medical

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

Not all poo is created equal: ...
A new study has discovered "super-donors" who have broad microbial diversity in their microbiome, leading to more successful results in fecal transplant treatments
A new study has discovered "super-donors" who have broad microbial diversity in their microbiome, leading to more successful results in fecal transplant treatments
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A new study has discovered "super-donors" who have broad microbial diversity in their microbiome, leading to more successful results in fecal transplant treatments
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A new study has discovered "super-donors" who have broad microbial diversity in their microbiome, leading to more successful results in fecal transplant treatments

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.

"In inflammatory bowel disease and diabetes for example, keystone species that are associated with prolonged clinical remission produce butyrate – a chemical with specialized functions in regulating the immune system and energy metabolism," says O'Sullivan.

Interestingly, however, research has shown that when these beneficial keystone species are isolated and administered individually, for example in the form of a probiotic, they are not as effective as when delivered as part of a whole stool sample. The researchers hypothesize the failure of this kind of precision medicine implies that microbial structure as a whole plays a greater role in the success of fecal transplants than simply the actions of a single microbial species.

"For example, the success of fecal transplants has been associated in some studies with the transfer of viruses which infect other gut microbes," explains O'Sullivan. "Some cases of recurrent diarrheal infection have even been cured with transplants of filtered stool, that has had all the live bacteria filtered out but still contains DNA, viruses and other debris."

Ultimately, the researchers conclude that while it may be incredibly difficult to clearly characterize what makes an effective fecal super-donor, it is vital for future fecal transplant research to take into account the specificities of individual donor microbiomes. On a general level, a broad diversity of gut microbiota is the best metric to identify a super-donor but it is also suggested that supporting the transplanted microbiome through an adjusted diet in the recipient may be fundamental to a fecal transplant's success.

The study was published in the journal Frontiers in Cellular and Infection Microbiology.

Source: University of Auckland

5 comments
gerrit50
Poop transplant has a much longer history than most people realize. In the middle ages you could buy poop from hermits or other people with a saintly status in the form of pills in the weekly market. The pills were supposed to enhance your health and they probably did!
Doodah
I donated to a friend who had near constant diarrhea and he claimed that it almost immediately cured, or mostly cured, his symptoms. It appeared to be almost miraculous.
EZ
Personally, I'd rather eat the right materials to enhance my own microbial community than take a load from someone else's. There are many natural or isolated compounds that can do the job but you won't learn about them from your neighborhood "health care provider."
Daishi
It's useful research. I've heard plausible theories that people that have had lime disease for instance go on to experience symptoms even after the disease is wiped out in part because the powerful anti-biotics taken destroy both good and bad bacteria. As people respond to anti-biotic resistant diseases with more and stronger antibiotics this could become a larger problem than it is now. If pro-biotics are less effective than healthy bacteria transplant (something supported by evidence) then fecal transplant could become more common and we have a stronger need to understand it.
Gregg Eshelman
It's also been discovered that keeping oxygen away from the poo during the process leads to much better results. The bacteria is all anaerobic, which of course is normal inside intestines.
Exposure to oxygen kills anaerobic bacteria which is why hyperbaric chambers can be used to treat stubborn infections by increasing the patient's blood oxygen levels above what's normal.