Pourquoi la flore intestinale a-t-elle vocation à devenir médicament ?

The gut microbiota (or gut flora) is a set of bacteria living in symbiosis with the host. Strictly associated with the intestinal tract and interacting with it, the gut microbiota is not a tissue nor an organ, but a supra-organism. A disruption of dialogue between bacteria and human cells is a risk factor or a possible cause of various diseases. The restoration of this dialogue, thanks to the transfer of the gut microbiota of a healthy individual to a patient whose balance of gut flora has been broken, is a new therapeutic approach. If its exact effect still eludes scientific understanding, its clinical benefit is well established for an indication, and is recently being tested for many others. The proven contribution of gut microbiota in the human physiological balance calls for intensifying research throughout the world about the state of knowledge and technologies, as well as on the legal and ethical dimension of fecal microbiota transfer. This didactic paper updates the questions in relation with this therapeutic act.