Clinical relevance of the relationship between changes in gut microbiota and bile acid metabolism in patients with intrahepatic cholangiocarcinoma

Although only 10-15%of liver cancers are cholangiocarcinomas(CCAs),which derive from the epithelial cells of the biliary tree,these cancers constitute a serious and growing health problem worldwide.The rate of mortality due to this tumor is very high because CCA usually appears in aged people and very often,in more than 70%of cases,are diagnosed late because of:(I)their anatomical localization in a big organ like the liver;(II)the lack of specific symptoms during most time of their development;and(III)the absence of available accurate,specific and sensitive biomarkers(1).These characteristics reduce the rate of success of surgical resection,which is the only curative option for CCA patients,because the response of this aggressive cancer to the available pharmacological armamentarium is extremely feeble(2).This justifies the interest of many groups to identify non-invasive markers to achieve early diagnosis that also permit to distinguish CCA from non-malignant biliary diseases and from hepatocellular carcinoma(HCC),the most frequent liver cancer,which derives from hepatocytes(3).