Abstract
Human gut microbiota consists of bacteria, archaea, fungi and viruses, and its composition, specific to each individual, is shaped by many factors. Pathological imbalance in the composition and/or diversity of microorganisms (dysbiosis), is associated with a wide range of diseases.
The intestinal microbiome is the result of a complicated interplay between the host and the intestinal microflora. Critically ill patients have a reduced number of symbiotic bacteria ( particularly Firmicutes and Bacteroidetes) and, conversely, a relative increase in pathogenic intestinal bacteria (particularly Proteobacteria), and the rate of dysbiosis is directly proportional to the severity of their condition.
On the other hand, the intestinal microbiota affects the permeability of the intestinal barrier, immune regulation, systemic inflammation, and, in turn, influences the clinical condition of critically ill patients. Altering the composition of intestinal bacteria by probiotics, prebiotics or antibiotics has long been used in intensive care.
Ultimate intervention to affect the intestinal microbiota is fecal microbial transplantation (FMT) from healthy donors. In critically ill patients, FMT is described in case reports and case series as effective and safe method in the treatment of dysmicrobia in severe and fulminant C. difficile colitis, antibiotic-associated diarrhea, severe forms of inflammatory bowel disease or as a rescue therapy of sepsis.
Despite the undisputable biological plausibility and positive effect observed in individual patients, FMT cannot be recommended as a routine procedure in this high-risk population, as high-quality prospective controlled clinical studies are completely absent. The article summarizes directions of future research and the method of implementation of FMT in critically ill patients.