Influence of proton pump inhibitors on microbiota in chronic liver disease patients

Background: Current knowledge suggests that proton pump inhibitors (PPIs) are associated with an increased risk of hepatic encephalopathy (HE) and spontaneous bacterial peritonitis (SBP). These conditions and PPI use are related to gut microbiota. The aim of this study is to research the changes in gut microbiota caused by PPI in patients with chronic liver disease. Methods: From 198 Japanese patients, 31 patients in the PPI and non-PPI groups were matched using propensity score matching (PSM) based on age, sex, and Child–Turcotte–Pugh class. We investigated the gut microbial composition of stool samples using the Illumina MiSeq sequencing platform and compared them using linear discriminant analysis effect size and phylogenetic investigation of communities by reconstruction of unobserved states. Results: Before PSM, Child–Turcotte–Pugh score (p = 0.038), ascites (p = 0.049), encephalopathy (p = 0.023), and esophageal varices (p < 0.01) were significantly higher in the PPI group than in the non-PPI group. After PSM, six genera, consisting of Lactobacillus, Streptococcus, Selenomonas, Veillonella, Campylobacter, and Haemophilus were enriched in the PPI group. Eggerthella, Paraprevotella, Turicibacter, Dorea, Anaerotruncus, and Ruminococcus were less abundant in the PPI group. We identified five types of level 3 KEGG pathways predicted to be significantly different. Conclusions: Part of microbial changes caused by PPI use was common to the changes by progression of liver cirrhosis. Increases in oral bacterial flora and decreases in autochthonous flora may produce the intestinal environment which tends to make the risk factor for HE or SBP.