A healthy intestinal microbiota protects us from infections, produces beneficial substances, keeps inflammation, cardiovascular diseases and tumors at bay. When its balance is altered, however, it can predispose to the onset of gastrointestinal diseases and chronic inflammation which, in turn, represents a risk factor for many serious pathologies. As a rule, it is enough to pay attention to correct lifestyles, nutrition, and perhaps use some probiotics, to rebalance the intestinal flora. When the situation becomes more serious, however, it is possible to resort to the so-called fecal transplant, or intestinal microbiota transplant. Marialuisa Novi, gastroenterologist at the SS Antonio e Biagio and Cesare Arrigo University Hospital of Alessandria, and Councilor of the AIGO (Italian Association of Hospital Gastroenterologists) Board of Piedmont/Valle d’Aosta, explains to us what it is, when it can be used and what effects it has on the health of our intestines.
Doctor, what is the intestinal microbiologist and why is it so important?
“The intestinal microbiota is made up of more than 100,000 billion microorganisms that colonize our intestine in a symbiotic way, that is, without causing us damage. In this abundant and varied microbial environment, bacteria are certainly the most represented population (the famous “good bacteria”) , but viruses and fungi are also present, which coexist in a complex and delicate balance, beneficial for our state of health. The intestinal microbiota performs numerous very important functions: it contributes, for example, to the synthesis of vitamins and short-chain fatty acids, essential for the correct functioning of tissues and organs, and constitutes the outermost part of the intestinal barrier, in direct contact with all food antigens and exogenous substances that we introduce from the outside through the digestive tract.”
Does it also influence the functioning of the immune system?
“Certainly: the intestinal microbiota, so strategically positioned, is involved in food tolerance mechanisms and, through a complex communication network with cells of the local immune system, contributes to maintaining a correct balance between pro-inflammatory and anti-inflammatory states. The destruction of this balance predisposes to intestinal infections, food intolerances (secondary to dysbiosis), and even to the onset of systemic diseases supported by chronic inflammation.”
How do problems with the intestinal microbiota arise?
“Many factors can damage its delicate balance: an unbalanced eating style, an intestinal infection, the use of antibiotics and antacids. Even during fetal life and in the first months of life there are factors that can influence the long-term health of the microbiota: the mother’s diet during pregnancy, the use of drugs, artificial breastfeeding, the environment, are all factors that can negatively and even permanently influence the microbiota.”
Is it in these cases that fecal transplant is used?
“Nowadays the only therapeutic indication for microbiota transplantation approved by the National Health System is the treatment of recurrent drug-resistant Clostridium Difficile colitis. This is an infection that we could define as opportunistic, as Clostridium difficile , in conditions of intestinal balance, would be a harmless commensal bacterium of our organism. Its toxicity manifests itself in fragile, immunosuppressed, hospitalized patients subjected to protracted antibiotic therapies. Subjects, therefore, suffering from probable intestinal dysbiosis. From here the “the intuition of treating a bacterial infection not with further antibiotic therapy, but rather by promoting the reconstitution of the normal intestinal ecoflora, to thus reduce the toxicity of the bacterium. The most effective and quickest way to do this consists precisely in microbiota transplantation.”
What does the procedure consist of?
“In extreme summary, it is a process through which the intestinal microbiota of a healthy individual is extracted to transfer it into the intestine of a sick person. The procedure begins with the recruitment of a donor, which is carried out by the gastroenterologist, selecting through clinical examination, physical and medical history of subjects with a high chance of possessing a varied and balanced intestinal ecoflora. The microbiologist carries out accurate tests on the donor’s blood and faeces to exclude potential transmissible infections during the procedure. The microbiota is then extracted from the donated faeces, and then , once adequately prepared, is infused into the recipient. The infusion technique that is most effective, albeit invasive, is colonoscopy, a modality which, also in our experience, has been found to be free of major adverse events. It is however possible to carry out the transplant also using an enema, or special concentrates to be taken orally.”
What are the benefits of this procedure?
“The transplant of microbiota extracted from a carefully selected donor allows the recipient to obtain a balance of the microbial species of his intestinal ecoflora. This reduces the state of chronic inflammation induced, in conditions of dysbiosis, by the constant stimulation of the intestinal immune system. Furthermore, the restoration of the intestinal barrier in the microbiota component increases defenses against pathogenic microbial species.
In the case of recurrent drug-resistant Clostridium difficile infections, microbiota transplantation has been shown to help eliminate disease recurrence. This is the only therapeutic indication for which it is currently approved in our country, but there is a long list of other pathologies, not just intestinal, against which it represents a promising therapeutic option. We are basically talking about all the pathologies that are linked to a chronic inflammatory state: cardiac, metabolic and neurodegenerative diseases. And even oncological: there are in fact numerous studies that have already demonstrated that the effective modulation of the intestinal ecoflora improves the response to some chemotherapies. Supporting clinical and laboratory research on the topic of microbiota will therefore allow us to expand the clinical indications of this procedure to many other pathological conditions induced by intestinal dysbiosis in the future.”
What risks can the transplant entail?
“Every therapeutic procedure involves risks, and for microbiota transplantation they consist of an infectious risk resulting from the transmission of pathogenic microbial species with the donor’s microbiota. It is clear that the clinical selection process performed by the gastroenterologist, and the execution of accurate and meticulous microbiological tests on the blood and feces of the donor, reduces the risk to almost zero. This is why it is a very safe procedure when it is carried out in accredited centers. In Italy, around 10 structures have passed the certification criteria. We in Alessandria we obtained certification in June 2022, the first in the Piedmont Region, and to date we have performed 19 transplants in subjects suffering from recurrent colitis due to C. difficile, and two transplants for compassionate purposes, outside the standard indication following approval from the ethics committee.”
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