In the autumn, Bellvitge and Clínic hospitals will carry out a campaign to recruit stool donors to be able to perform microbiota transplants for all citizens who need them.

In addition, having a stable pool of donors will make it possible to investigate which diseases can be treated in the future with microbiota transplants, an emerging field of research in Europe and North America. The candidates, in which the intestinal microbiota plays a relevant role but the clinical efficacy of faecal transplants has not yet been demonstrated, include different types of cancer and psychiatric disorders.

The project has the support of the Consorci de Salut i Social de Catalunya (CSC), which will provide 600,000 euros during the second semester of this year for the launch of the Catalan microbiota bank.

So far, the only disease in which microbiota transplants have proven effective is recurrent infection with Clostridioides difficile, a common bacteria in hospitals that causes diarrhea and can be fatal in people in fragile health. It is estimated that around one in a thousand people contract the infection each year, according to data from the United States, which is equivalent to around 8,000 people a year in Catalonia and 48,000 in Spain.

Although the majority of cases are cured, faecal microbiota transplantation is the only treatment option for a minority of patients, for whom it offers an expectation of cure of more than 90%. “In Catalonia we should be treating between 150 and 300 people a year”, informs Jordi Guardiola, head of the digestive system service at Bellvitge hospital and one of the promoters of the project.

The funding from the CSC will make it possible to consolidate the already existing microbiota banks in Bellvitge and the Clinic, which were created with scarce resources at the initiative of a small group of professionals. This is where the donations will be received, processed and stored, and from where they will be distributed to centers throughout Catalonia that treat Clostridioides difficile infections. The hospitals of Vic, Granollers and Igualada, among others, participate in the project.

To offer microbiota transplants to a larger number of patients starting in the fall, the Bellvitge teams and the Clinic will need a larger number of donors. They must be healthy people under the age of 50 and must not have risk factors or behaviors that could compromise the safety of their intestinal microbiota.

Just as there are protocols to guarantee the safety of blood donations, “with the microbiota we must also take extreme precautions to ensure that a disease cannot be transmitted through the donation”, informs Climent Casals, head of the service of microbiology at the Clínic hospital in Barcelona and one of the architects of the project.

Since the selection process for stool donors is longer and more expensive than for blood donors, microbiota banks prefer to have few regular donors rather than many sporadic ones. In the Netherlands, about twenty donors supply microbiota for the whole country, reports Casals.

In Spain the donation is unpaid. But they try to give the volunteers the maximum facilities, like going to pick up the donations at home so they don’t have to travel.

When they arrive at the laboratory, the stools are processed to separate the microbiota from the waste and freeze-dried to obtain a powder that is packaged in capsules. In this way, patients who receive the treatment will have the feeling of ingesting a medicine like any other.

Between 10 and 20 capsules are usually obtained for each deposition of a donor, informs Jordi Guardiola, from the Bellvitge hospital. On average, the capsules obtained from a deposition allow one person’s treatment to be completed.

Looking to the future, “having a stable group of donors will allow us to investigate the potential of the microbiota for the treatment of different diseases”, emphasizes Climent Casals. Studies published in recent months have revealed that the gut microbiota is related to the effectiveness of cancer immunotherapies, suggesting that modifying the microbiota could improve the effectiveness of some cancer treatments.

I also “see enormous potential in psychiatry”, adds Casals, since the microbiota has been linked to different mental health disorders such as – among others – depression, anorexia or autism.

In the shorter term, the Clínic and Bellvitge teams plan to investigate whether microbiota transplants can be effective for ulcerative colitis and recurrent urinary tract infections.

“The creation of the microbiota bank of Catalonia will facilitate access to the treatment of a high number of intestinal diseases that are increasingly present in our population, as well as facilitate and promote scientific research related to the role of the microbiota in the health and diseases”, emphasizes Antoni Gilabert, Director of Innovation and Partnerships at the CSC.

“The microbiota represents a paradigm shift in microbiology”, concludes Climent Casals. “We are at the beginning”.