Peritoneal microbiome in end-stage renal disease patients and the impact of peritoneal dialysis therapy

The following are available online at http://www.mdpi.com/2076-2607/8/2/173/s1, Figure S1 (Rarefaction curves), Figure S2 (Relative proportion taxa for class, order, genus, and species), Figure S3 (Abundances of the genera and families between the ESRD-PD and ESRD-nonPD), Figure S4 (Alpha diversity of the peritoneum microbiome community at phylum, class, order, family, genus, species and OUT taxonomic levels calculated with Observed, Chao1, Shannon, Simpson, and Inverse Simpson indexes), Figure S5 (Beta-diversity of the peritoneum microbiome community at OTU level with Bray-Curtis, Jaccard, unweighted Unifrac, and Weighted Unifrac) and Figure S6 (Non-metric multidimensional scaling of blood and peritoneum microbiomes of non-PD and PD patients).
Factors influencing the occurrence of peritoneal dialysis (PD)-related infections are still far from fully understood. Recent studies described the existence of specific microbiomes in body sites previously considered microbiome-free, unravelling new microbial pathways in the human body. In the present study, we analyzed the peritoneum of end-stage kidney disease (ESKD) patients to determine if they harbored a specific microbiome and if it is altered in patients on PD therapy. We conducted a cross-sectional study where the peritoneal microbiomes from ESKD patients with intact peritoneal cavities (ESKD non-PD, n = 11) and ESKD patients undergoing PD therapy (ESKD PD, n = 9) were analyzed with a 16S rRNA approach. Peritoneal tissue of ESKD patients contained characteristically low-abundance microbiomes dominated by Proteobacteria, Firmicutes, Actinobacteria, and Bacteroidetes. Patients undergoing PD therapy presented lower species richness, with dominance by the Pseudomonadaceae and Prevotelaceae families. This study provides the first characterization of the peritoneal microbiome in ESKD patients, bringing new insight to the human microbiome. Additionally, PD therapy may induce changes in this unique microbiome. The clinical relevance of these observations should be further explored to uncover the role of the peritoneal microbiome as a key element in the onset or aggravation of infection in ESKD patients, especially those undergoing PD.
This research was funded by FEDER—Fundo Europeu de Desenvolvimento Regional funds through the COMPETE 2020—Operacional Programme for Competitiveness and Internationalisation (POCI), Portugal 2020, and by Portuguese funds through FCT/MCTES in the framework of the project MicroMOB “POCI-01-0145-FEDER-029777 / PTDC/MEC-MCI/29777/2017”; and by a Research Grant 2014 by the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) to I.S.-S. L.S.-S was supported by SFRH/BD/84837/2012 and I.S.-S was supported by SFRH/BPD/101016/2014 from FCT/QREN–POPH/FSE.