Helicobacter pylori and the liver: any relationship?

Abstract Helicobacter pylori infection is being correlated to a number of human diseases, among which also those of the liver. From a clinical point of view, 4 "areas of interest" for the suggested correlation can be identified: 1. Helicobacter pylori and portal hypertension-related congestive gastropathy in cirrhotics. There are, in the literature, at least 7 studies confirming that the microorganism has no role in causing or worsening the disease. 2. Helicobacter pylori and duodenal ulcer in cirrhotic patients. Apparently, in the cirrhotic patient, the microorganism has no role in causing duodenal ulcer. 3. Helicobacter pylori, ammonia production and hepatic encephalopathy. In this case, there are at least three studies showing that Helicobacter pylori infection increases the risk of developing encephalopathy in the cirrhotic patient, this being a somewhat expected finding. 4. Helicobacter pylori infection in chronic liver disease and its diagnosis. Evidence in the literature suggests: a) that hypertensive gastropathy might not represent a favourable environment for Helicobacter pylori thus making the diagnostic sensitivity of the biopsy lower than expected, and b) that even serological diagnosis might provide data of difficult interpretation, as shown in non alcoholic cirrhosis and, by our own group, in primary biliary cirrhosis. More intriguing are the data generated with respect to the potential capacity of Helicobacter pylori and Helicobacter pylori-like bacteria such as, in particular, Helicobacter hepaticus to damage the liver by producing toxins with a granulating effect on liver cell lines which, in vivo, through the portal tract, might reach the liver, thus causing hepatocellular damage. The point has been addressed by a number of investigators and autoimmune mechanisms have also been suggested. In summary, from the clinical point of view, some evidence suggests that Helicobacter pylori infection might be relevant in the pathogenesis of hepatic encephalopathy in cirrhosis. The data being generated with respect to a direct hepatotoxicity are, at present, stimulating but only speculative.