Gut microbiota, probiotics and liver diseases
From a physiological perspective, there is a strong relationship between liver and gut and recent studies indicate a pivotal role for the intestinal microbiota in promoting healthy liver function. Alterations of the intestinal microbiota may play an important role in induction and promotion of liver damage resulting in cirrhosis and its complications. Mechanisms involved in the pathogenesis of liver damage and its complications include: bacterial overgrowth, immune dysfunction, alteration of the luminal factors and altered intestinal permeability. Probiotics have been suggested as a useful integrative treatment for different types of chronic liver damage, for their ability to augment intestinal barrier function and prevent bacterial translocation. This review summarizes some principal findings on this topic.
Liver and gut are anatomically and functionally linked. The portal system receives the blood from gut and the intestinal blood content activates hepatic functions (1). The liver in turn affects the intestinal functions through the bile secretion into the intestinal lumen and cholecystokinin, secretin, motilin, and other intestinal peptides affect the bile production and liver function after meals (2).
The intestinal microbiota is a complex ecological system and is composed of thousands of different bacterial species for each portion of the alimentary tract. In physiological conditions, bacteria influence many intestinal functions, such as the production of vitamins, the degradation of bile acids, the digestion of nutrients and affect local and general immunity (3). Finally, together with the intestinal mucosa, the endogenous intestinal flora forms an important barrier against pathogens by the mechanism of colonization resistance.
The causes of liver damage are different (viral, toxic, metabolic, etc.), but pathogenetic mechanisms (inflammation, steatosis, fibrosis, cirrhosis) are similar.
Alterations of intestinal mic ...