Intestinal Microbiota in Patients with Chronic Hepatitis C with and Without Cirrhosis Compared with Healthy Controls

Background & Aims: The importance of the intestinal microbiota for the onset and clinical course of many diseases, including liver diseases like non-alcoholic steatohepatitis and cirrhosis, is increasingly recognized. However, the role of intestinal microbiota in chronic hepatitis C virus (HCV) infection remains unclear.

Methods: In a cross-sectional approach, the intestinal microbiota of 95 patients chronically infected with HCV (n=57 without cirrhosis [NO-CIR]; n=38 with cirrhosis [CIR]) and 50 healthy controls (HC) without documented liver diseases was analysed.

Results: Alpha diversity, measured by number of phylotypes (S) and Shannon diversity index (H'), decreased significantly from HC to NO-CIR to CIR. S and H' correlated negatively with liver elastography. Analysis of similarities revealed highly statistically significant differences in the microbial communities between HC, NO-CIR and CIR (R=.090; P<1.0×10 ). Stratifying for HCV genotypes even increased the differences. In addition, we observed distinct patterns in the relative abundance of genera being either positive or negative correlated with diseases status.

Conclusions: This study shows that not only the stage of liver disease but also HCV infection is associated with a reduced alpha diversity and different microbial community patterns. These differences might be caused by direct interactions between HCV and the microbiota or indirect interactions facilitated by the immune system.