Gut bacterial translocation contributes to microinflammation in experimental uremia

Abstract

Background: Microinflammation frequently develops in chronic uremia with pathological intestinal changes. However, the relationship between gut bacterial translocation and microinflammation in uremia has not been widely investigated. Aim: This study aimed to investigate whether gut microbiome dysbiosis and translocation occurred in experimental uremia, and whether they consequently contributed to microinflammation. Methods: Forty rats underwent surgical renal mass 5/6 ablation. The surviving (uremic group, n = 21) and healthy (sham group, n = 20) rats were used in the experiment. Postoperative blood, livers, spleens, and mesenteric lymph nodes (MLNs) were subjected to bacterial 16S ribosomal DNA amplification to determine if bacteria were present. Bacterial genomic DNA samples from the MLNs and colon were amplified with specific primers designed by the 16S rRNA sequence of the species obtained from blood, livers, and spleens. Pyrosequencing was used to analyze the colonic microbiome of each subject. Intestinal permeability to 99mTc-DTPA, plasma hs-CRP, and IL-6 were measured. Results: Bacterial DNA in extraintestinal sites and altered colonic microbiomes were detected in some rats in the uremic group. Bacterial genomic DNA in MLNs and colon were obtained by primers specific for bacterial species observed from blood, livers, and spleens of identical individuals. Intestinal permeability, plasma hs-CRP, and IL-6 levels were statistically higher in the uremic group compared with the sham group. Plasma hs-CRP and IL-6 were significantly higher in uremic rats with bacterial DNA in their blood than in those without. Conclusions: Gut microbiome dysbiosis occurs and bacteria translocate to the systemic and lymph circulation, thereby contributing to microinflammation in experimental uremia. © Springer Science+Business Media, LLC 2012.