Gut microflora in the pathogenesis of the complications of cirrhosis

Bacterial translocation and its consequences in patients with cirrhosis

Bacterial translocation is the passage of viable bacteria from the intestinal lumen to mesenteric lymph nodes and other extraintestinal sites. Spontaneous bacterial peritonitis is the main clinical consequence of bacterial translocation in cirrhosis. Translocation of bacterial products of viable or non-viable bacteria, such as endotoxin and/or bacterial DNA, through the intestinal wall could stimulate the immune system and the hyperdynamic circulatory state in cirrhosis with clinical consequences that are under evaluation. Bacterial translocation is currently considered the passage of viable gut flora across the intestinal barrier to extraluminal sites. Aerobic Gram-negative bacilli are the most common translocating bacteria. Intestinal bacterial overgrowth, impairment in permeability of the intestinal mucosal barrier, and deficiencies in local host immune defences are the major mechanisms postulated to favour bacterial translocation in cirrhosis. Bacterial translocation is a key step in the pathogenesis of spontaneous bacteraemia and spontaneous bacterial peritonitis in cirrhosis. Translocation of intestinal bacterial products from viable or non-viable bacteria, such as endotoxin and bacterial DNA, has recently been associated with pathophysiological events, such as activation of the immune system and derangement of the hyperdynamic circulatory status in cirrhosis. Clinical consequences of these effects of bacterial products are presently under investigation.