Intestinal Microbiota Modulation by Fecal Microbiota Transplantation in Nonalcoholic Fatty Liver Disease

Numerous factors are involved in the pathogenesis of nonalcoholic fatty liver disease (NAFLD), which are responsible for its development and progression as an independent entity, but also thanks to their simultaneous action. This is explained by the hypothesis of multiple parallel hits. These factors are insulin resistance, lipid metabolism alteration, oxidative stress, endoplasmic reticulum stress, inflammatory cytokine liberation, gut microbiota dysbiosis or gut-liver axis activation. This is a systematic review which has an aim to show the connection between intestinal microbiota and the role of its disbalance in the development of NAFLD. The gut microbiota is made from a wide spectrum of microorganisms that has a systemic impact on human health, with a well-documented role in digestion, energy metabolism, the stimulation of the immune system, synthesis of essential nutrients, etc. It has been shown that dysbiosis is associated with all three stages of chronic liver disease. Thus, the modulation of the gut microbiota has attracted research interest as a novel therapeutic approach for the management of NAFLD patients. The modification of microbiota can be achieved by substantial diet modification and the application of probiotics or prebiotics, while the most radical effects are observed by fecal microbiota transplantation (FMT). Given the results of FMT in the context of metabolic syndrome (MetS) and NAFLD in animal models and scarce pilot studies on humans, FMT seems to be a promising treatment option that could reverse intestinal dysbiosis and thereby influence the course of NAFLD.