Faecal transplants can alleviate the painful and worrying symptoms of irritable bowel syndrome – if those transplants come from people called "super donors," according to a study presented on Sunday.
The large randomized double-blind placebo-controlled trial – considered the gold standard for medical research – found that fecal microbiota transplantation significantly improved the symptoms of IBS in nearly half of patients. The study was presented by lead researcher Magi El-Salhi, a professor in the Department of Clinical Medicine at the University of Bergen in Norway, at the annual United European Week of Gastroenterology in Spain.
The cause of IBS is unknown, but some researchers suggest that it may be related to anomalies in the microbiome, the multitude of microorganisms that inhabit the gut.
Faecal transplantation or fecal microbiota transplantation (FMT) works by repopulating the gut with a healthier array of microorganisms. The donor feces are processed and then transplanted into the recipient's gut.
To examine whether FMT can alleviate the symptoms of IBS, El-Salhi and colleagues recruited 164 patients who were diagnosed with the condition and who had moderate to severe symptoms.
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Prior to treatment, patients were questioned in detail about their symptoms. They were then randomly assigned to receive a 30 g solution containing their own stool – placebo – or one of two doses (30 g or 60 g) containing stool from a so-called super donor. Doses are delivered to the small intestine via a tube inserted into the mouth and down the throat.
Three months later, patients were again asked to describe in detail their symptoms. Compared to pre-treatment, 23.6 percent of patients in the placebo group reported a moderate improvement in symptoms. In the group that received the lower dose of super donor feces, 76.9 reported a moderate response and in the higher dose group, 89.1%.
More importantly, they also found a remission of symptoms – meaning that the symptoms disappeared completely – in 35.2 percent of those in the lower dose group and in 47.3 percent of those in the higher dose. This is compared to 5.5 percent of patients in the placebo group who report symptom remission.
One year later, El-Salhy said the effects seemed to have continued. "Preliminary results [suggest] of most, 90 to 95 percent of patients responded, are still good and about 50 percent are still" cured, "he wrote in an email.
Previous studies have also looked at the effects of FMT on IBS symptoms and found mixed results.
"We had a carefully selected donor from several candidates who have traits known to have a positive effect on the gut microbiota," said El-Salhi. Overall, the donor was healthy, breastfeeding, eating a diet, not taking regular medication, was a non-smoker, and had only taken antibiotics several times, he said.
Experts were delighted with the results, but somewhat skeptical. on the idea of a super donor, since it was unclear how the results of El-Salhi could be duplicated.
"These are very promising results that are sure to draw a lot of interest and attention because there is a lot of interest in them for the types of therapeutic agents for CHD," says Dr. Alexander Horuts, professor of medicine and medical director of the therapy program of microbiota at the University of Minnesota. "But it's unclear how you could find another 'super donor' to reproduce these results."
Dr. Jonathan Jacobs, an associate professor of medicine at the University of California, Los Angeles Medical School and director of UCLA Microbiome Core, agreed. If it turns out that such results are only possible with super-donor feces, which could be rare, "then we won't be any better," he said.
Given the mixed results in previous studies treating IBS with FMT, "I'm not sure this study will allow us to conclude that a super donor is needed, but rather FMT as a whole needs to be validated in additional studies," says Dr. Parna Kasyap, associate professor of medicine, physiology and biomedical engineering and co-director of the Microbiome program at the Mayo Clinic.
In fact, it is not yet clear what role intestinal bacteria play in CHD, and in fact, most studies show that the microbiome of people with IBS is similar to that of healthy people, Kashyap wrote in an email. With that in mind, "how do you decide on a good donor?" Add Kashyap.
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