The urogenital microbiome in chronic kidney disease patients on peritoneal dialysis

Abstract

Introduction and objectives: Diabetes, dyslipidemia, older age, gender, urinary tract infections, and recent antibiotic intake have been associated with a decrease in the urobiome richness and other fluctuations in this microbiome. Gut and blood microbiome have been reported to be altered in patients with chronic kidney disease (CKD), and specifically in peritoneal dialysis (PD) patients. Still, there are currently no studies describing the urogenital microbiome in CKD-PD patients. In this study we characterized the urobiome profile in 46 PD patients and analyzed its clinical and inflammatory parameters.

Materials and methods: Mid-stream urine, fecal and blood samples were collected from 46 patients undergoing PD at Centro Hospitalar Universitário de São João (CHUSJ) in Porto, Portugal. Exclusion criteria were age under 18 years old, inability to give informed consent, history of infection in the last three months, and antibiotic intake in the last three months. The microbiome communities were analyzed by amplification and sequencing of the V3-V4 region of the bacterial 16S rRNA gene. Correlations with the patients' clinical data and inflammatory profile were performed.

Results: CKD-PD patients presented a unique urobiome profile dominated by Bacillota, Actinomycetota and Pseudomonadota and characterized by a lower Shannon diversity than fecal and blood microbiome. The taxonomic profiles of urogenital samples were organized in multiple subtypes dominated by populations of Lactobacillus, Staphylococcus, Streptococcus, Gardnerella, Prevotella, Escherichia-Shigella, being similar to other non-PD-CKD patients. Gender, sCD14, residual diuresis and history of peritonitis were significantly associated to variations in the urobiome. Although not reaching statistical significance, diabetes and the time on PD also showed association with particular taxonomic groups. Depletion of Gardnerella, Staphylococcus, Corynebacterium, Lactobacillus or Dermabacter populations correlated with CKD-PD patients with history of diabetes, history of peritonitis and altered levels of sCD14.

Conclusions: Our results highlight urogenital microbiome as a potential partner and/or marker in the overall health state of CKD-PD patients.

Keywords: Chronic kidney disease; Diálisis peritoneal; Enfermedad renal crónica; Gut microbiome; Human microbiome; Infección del tracto urinario; Microbioma humano; Microbioma intestinal; Microbioma urogenital; Peritoneal dialysis; Urinary tract infection; Urobioma; Urobiome; Urogenital microbiome.