Fecal Transplants: "Super-Pooper" Donors Help Treat IBD, Chronic Diarrhea
"Perhaps they have a genetic background that selects for them."
It makes intuitive sense that correcting hard-to-treat digestive issues requires restoring the health of the gut. Far less intuitive is the idea of doing so using poop. All humans innately know that fecal matter is dirty and respond to it with disgust. But as scientists have discovered in recent years, stool is laden with gut bacteria that seems to be beneficial to people with digestive illnesses — and some people’s poop, as researchers report in a new review, is more valuable than others.
On January 21, New Zealand researchers publishing in Frontiers in Cellular and Infection Microbiology report the existence of “super donors,” charmingly known as super poopers. The review of the existing literature suggests that these people, who supply stool banks with fecal samples, seem to have poop that is especially helpful in treating illnesses like C. difficile infections or inflammatory bowel disease.
Though the existence of super-donors is still “a hypothetical concept,” Brooke Wilson, the first author on the new paper, tells Inverse, the limited literature suggests these people have a higher diversity of microbes in their gut and a relative abundance of bacteria that produce a compound called butyrate. Wilson is a Ph.D. candidate at the University of Auckland who worked with molecular biologist Justin O’Sullivan, Ph.D., on the review.
“We see transplants from super-donors achieve clinical remission rates of perhaps double the remaining average,” said O’Sullivan.
Why Super Poopers Are Important
A healthy human gut is home to some 100 trillion bacteria, representing about 1,000 different species, collectively known as the gut microbiota. In addition to digestive health, this menagerie of microscopic life has been implicated in mental health, cancer, and even heart disease. It’s still not fully clear how fecal transplantation helps, but the general idea is that imbalances in the makeup of the gut microbiota can make people sick, and implanting poop from a healthy person into a sick person’s gut can reset the balance.
In a previous interview with Inverse, Carolyn Edelstein, a founder of OpenBiome, America’s first stool bank, explained how FMT seems to help people whose recurrent C. difficile gut infections fail to respond to antibiotics:
For those folks who get into these multiple recurrent cycles of infection, it turns out that fecal transplants work about 90 percent of the time to get rid of the infection. It’s pretty crazy. These are people who may have been sick for months or years, and when it works, they’re basically better the next day.
And if you’re one of those patients lucky enough to get a stool transplant from a hypothetical super-pooper, then you’re in luck.
What Makes a Pooper Super?
The early research on especially helpful donors suggests super-poopers have two key qualities: They seem to have diverse gut bacteria, and they have relatively high levels of so-called “keystone species” that produce the compound butyrate.
"…perhaps they have a genetic background that selects for them.
As O’Sullivan and his team write, the literature shows that people who respond positively to treatment generally tend to have an increase in microbial diversity and take on the microbial makeup of the poop donor. High diversity, in other words, adds to a donor’s “super” status.
Meanwhile, it’s a plus when a donor’s gut contains species that can produce butyrate, which not all bacteria can do. Butyrate works with the immune system and is an energy source for the cells lining the gut, says Wilson. “We don’t know when exactly a super-donor acquires these ‘keystone-species’,” she points out. “They could have come from their diet, from their environment, or perhaps they have a genetic background that selects for them.”
How to Tell if You’re a Super Pooper
There’s a lot left to learn about super poopers, but it is clear they can help people with stubborn illnesses. Wilson says that the fecal transplant cure rate for antibiotic-resistant C. difficile infections is “over 90 percent.” Treatment for inflammatory bowel diseases like ulcerative colitis and Crohn’s disease induces remission in around 30 to 50 percent of patients, though long-term efficacy likely requires “top-up fecal transplants.”
"Unfortunately it is not so easy to predict who is a super-donor and who is not.
While the roughly 200 registered trials in the United States continue to uncover whether and how fecal transplants can help other ailments, it wouldn’t hurt to donate poop at OpenBiome and find out if you’re a super-pooper yourself.
“Unfortunately it is not so easy to predict who is a super-donor and who is not,” says Wilson. “I would say that the best approach if you want to be more like a super-donor is to eat a varied diet that is high in fibre. A varied diet will encourage microbial diversity — a feature of super-donors.” It’s possible one of the species you acquire might be a butyrate-producing keystone species, she says.
“However,” she points out, “it is important to stress that we still have a lot to learn about whether super-donors do exist and if so, what makes their poop more effective at treating certain diseases.”
“We will have to wait and see.”