Ulcerative colitis (UC) is an inflammatory bowel disease suggested associated with a profound alteration of the gut microbiota. A group of researchers recently demonstrated that multidonor transplantation of faecal microbiota induces clinical remission among UC patients.
Ulcerative colitis (UC) is an inflammatory bowel disease clinically characterized by abdominal pain and diarrhea, among other symptoms. The disease has a strong autoimmune component and current treatment involves oral administration of immunosuppressive and anti-inflammatory drugs. Alternative therapeutic approaches offering less adverse side effects to the patients remain poorly studied.
It is now well established that UC entails a profound alteration in the diversity of the gut microbiota, a term describing the community of microorganisms residing in our intestines in a mutually beneficial relationship. To date, only two studies have investigated whether microbiota transplantation might induce clinical remission from UC and they show conflicting results. Importantly, in both studies transplants originated from a single donor and one study suggested this might induce significant variability in the final clinical outcomes.
To circumvent this issue, a group of Australian investigators recently tested whether multidonor transplantation of gut microbiota might induce complete remission from UC. The study was performed in three different Australian hospitals from November 2013 to May 2015 and the results were recently published in The Lancet. The study included a total of 81 UC patients, of which 40 received a placebo colonoscopic infusion and 41 received a microbiota transplant originating from three to seven unrelated donors. Patients and clinicians were blinded to the treatment type. Following the initial procedure by a clinician, placebo or microbiota was self-administered by the patients five days per week for 8 weeks. Several weekly visits with a clinician were scheduled to assess the progression of symptoms. Moreover, stool samples were collected at weeks four and eight to assess microbiota diversity by 16S rDNA sequencing.
Overall, the authors demonstrate that their approach is promising. They show that intensive-dosing, multidonor, faecal microbiota transplantation induced clinical remission in UC patients. In fact, 11 (27%) of the patients in the treatment group achieved clinical remission compared to only three (8%) in the placebo group, a statistically significant difference (p=0.021). Furthermore, microbiota transplantation was not accompanied by any significant difference in the occurrence or severity of adverse side effects. Finally, 16S rDNA sequencing revealed that while the microbiological diversity of the microbiota did increase compared to baseline levels among UC patients, most samples showed lower levels of microbiological diversity compared to donor batches. Thus, taken together, the results argue in favour of implementing multidonor microbiota transplantation in the treatment of UC.
Written By: Samuel Rochette, M.Sc