What is already known on this topic
Allogenic stem cell transplantation is the only therapy for some hematological diseases, including certain types of blood cancer. But the treatment can lead to graft-versus-host disease, a life-threatening immune condition that affects various organs, including the gut.
What this research adds
Researchers found that fecal microbial transplant could ameliorate symptoms of intestinal graft-versus-host disease in 15 people who received allogenic stem cell transplantation. Within a month of treatment, intestinal graft-versus-host disease resolved and the gut microbial diversity was restored in most of the study participants.
Although the findings should be confirmed in larger studies, fecal microbial transplant could be a promising treatment for intestinal graft-versus-host disease.
Allogenic stem cell transplantation is the only therapy for some hematological diseases, including certain types of blood cancer. But the treatment can lead to graft-versus-host disease, a life-threatening immune condition that affects various organs, including the gut. Now, researchers have found that fecal microbial transplant could ease symptoms of intestinal graft-versus-host and restore gut microbial diversity.
The findings, published in Science Translational Medicine, suggest that fecal microbial transplant could be a promising treatment for intestinal graft-versus-host disease.
Previous studies have shown that fecal transfer has successfully treated intestinal disorders such as Clostridium difficile infection and ulcerative colitis. To investigate whether fecal microbial transplant could improve symptoms of intestinal graft-versus-host disease, Mette Hazenberg at Amsterdam University Medical Center and her colleagues transferred fecal bacteria from two healthy donors into the gut of 15 people who had received allogenic stem cell transplantation.
Transferring gut bacteria
Following the fecal transfer, some study participants reported side effects that included cramps and nausea, but all side effects resolved within hours. Within the first month after the transfer, five people developed an infection such as an ear or a bladder inflammation. One individual was diagnosed with pneumonia five days after fecal microbial transplant, and another individual was diagnosed with Escherichia coli sepsis originating from the urinary tract. Both people recovered after being treated with antibiotics.
In two-thirds of the study participants, or 10 people, fecal microbial transplant eased the symptoms of intestinal graft-versus-host disease, including diarrhea. Five participants did not respond to the fecal transfer, and four of them died from complications of graft-versus-host disease during follow-up.
In those who responded to treatment, intestinal graft-versus-host disease resolved within a month, and the gut microbial diversity increased in most of the participants.
Responders vs non-responders
The researchers found that individuals who responded to fecal microbial transplant started with a higher baseline gut microbial diversity compared to those who did not respond.
Responders also tended to have higher levels of butyrate-producing bacteria and Blautia compared to non-responders. The baseline abundance of Blautia bacteria in responders was comparable to that of healthy donors of fecal samples, and it increased after the fecal transplant.
The abundance of Clostridiales and butyrate-producing bacteria also increased in responders, reaching similar values as in the healthy donors. In contrast, the abundance of these bacteria remained stable or declined in individuals who did not respond to fecal transfer.
Although promising, the findings should be reproduced in larger groups of people to confirm the safety and efficacy of fecal transfer and to determine the optimal frequency, source, and timing of treatment in people with intestinal graft-versus-host disease, the researchers say.