Fecal transplanting is a technique for transferring intestinal bacteria from a healthy person to a sick person. While this process is promising for treating many bowel problems, researchers now realize that not all donors are equal, and that some feces have a much higher value than others.
Increasing knowledge about the microbiota, the billions of bacteria that colonize our digestive system and play a big role in our health, led to the emergence of a surprising technique: fecal transplantation.
This “transplant” makes it possible to transfer the bacteria present in the digestive system from one healthy person to another suffering from certain digestive diseases, in order to restore his intestinal flora.
However, by reviewing the studies published on the subject in recent years, a group of New Zealand researchers discovered that all donations of fecal matter are not equal (New Window) and that some people could even be described as super-donors.
As a result of their analysis, they propose a list of criteria that could help to design new, more targeted treatments that would increase the effectiveness of this technique.
A microscopic migration
Described for the first time in 1958, fecal transplantation has progressed significantly over the last three decades. One of the biggest successes of fecal transplantation is the treatment of recurrent infections with C. difficile .
These bacteria are usually eliminated with antibiotics, but in cases of recurrent infections, fecal transplantation is considered to restore a normal intestinal flora.
Our gut is home to hundreds of billions of bacteria of tens of thousands of different species. The composition of these species is influenced by where we are in the world, by our culture, our diet and our way of life.
These good bacteria are therefore obtained from stool samples from donors. After confirming that they do not contain any potential source of infection, the stool is suspended in liquid solutions and then implanted in the patient’s intestine by colonoscopy, endoscopy or ingestion of capsules.
In the case of C. difficile infections , the success rate of this type of treatment exceeds 90%. Studies have shown that this technique can also treat other conditions, such as ulcerative colitis or Crohn’s disease, two serious inflammatory bowel diseases that also decrease the diversity of intestinal flora.
A personalized super-donor
In contrast to C. difficile treatment , the success rate of fecal transplants for these inflammatory diseases was much lower.
However, by analyzing the data from several studies, the researchers noticed that the remission rate of patients with ulcerative colitis was twice as high when they received a transplant from a specific donor, which gave rise to the term “Super-donor”.
According to the researchers, several factors make it possible to identify a super-donor, the most important being a greater bacterial diversity than the average.
However, this diversity must be combined with the presence of specific bacteria that could play roles in the treatment of the targeted disease, such as the production of certain molecules. Other factors include the donor’s diet and immune compatibility between the donor and the recipient.
Other studies have also shown that bacteria are not the only important elements in a transfer: some viruses or molecules floating freely in the intestine can also have a major influence on the remission of some patients, ensuring survival or the good development of the transferred bacteria.
In sum, the researchers’ research shows that a personalized approach could make this treatment more effective, and could even extend its use to the treatment of obesity, cancer or neurodegenerative diseases.