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, 33 (2), 662-669

The Fecal Microbiome and Serum Concentrations of Indoxyl Sulfate and P-Cresol Sulfate in Cats With Chronic Kidney Disease


The Fecal Microbiome and Serum Concentrations of Indoxyl Sulfate and P-Cresol Sulfate in Cats With Chronic Kidney Disease

Stacie C Summers et al. J Vet Intern Med.


Background: Intestinal dysbiosis has been documented in humans with chronic kidney disease (CKD) and is thought to contribute to production of the uremic toxins indoxyl sulfate (IS) and p-cresol sulfate (pCS). Characteristics of the fecal microbiome in cats with CKD and correlation to serum concentrations of uremic toxins are unknown.

Objectives: To characterize the fecal microbiome and measure serum IS and pCS concentrations of cats with CKD in comparison to healthy older cats.

Animals: Thirty client-owned cats with CKD (International Renal Interest Society stages 2-4) and 11 older (≥8 years) healthy control cats.

Methods: Prospective, cross-sectional study. Fecal samples were analyzed by sequencing of 16S rRNA genes and Escherichia coli quantitative PCR (qPCR). Serum concentrations of IS and pCS measured using liquid chromatography tandem mass spectrometry.

Results: Cats with CKD had significantly decreased fecal bacterial diversity and richness. Escherichia coli qPCR showed no significant difference in bacteria count between control and CKD cats. Cats with stage 2 (P = .01) and stages 3 and 4 (P = .0006) CKD had significantly higher serum IS concentrations compared to control cats. No significant difference found between stage 2 and stages 3 and 4 CKD. The pCS concentrations were not significantly different between CKD cats and control cats.

Conclusions and clinical importance: Decreased fecal microbiome diversity and richness is associated with CKD in cats. Indoxyl sulfate concentration is significantly increased with CKD, and cats with stage 2 CKD may suffer from a similar uremic toxin burden as do cats with later stage disease.

Keywords: chronic renal disease; dysbiosis; feline; microbiota; uremic toxin.

Conflict of interest statement

Authors declare no conflict of interest.


Figure 1
Figure 1
Scatter plot of the number of observed unique operational taxonomic units (OTUs) in chronic kidney disease (CKD) and healthy control cats. Species richness was significantly decreased in CKD cats when compared to healthy control cats (P = .03)
Figure 2
Figure 2
Serum indoxyl sulfate (IS) concentrations in healthy control cats, chronic kidney disease (CKD) stage 2 cats, and CKD stages 3 and 4 cats. Significantly higher IS concentrations were seen in stage 2 CKD cats (P = .01) and stages 3 and 4 CKD cats (P = .0006) in comparison to healthy control cats. There was no statistical difference in IS concentrations between stage 2 CKD cats and stages 3 and 4 CKD cats

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    1. Vaziri ND, Wong J, Pahl M, et al. Chronic kidney disease alters intestinal microbial flora. Kidney Int. 2013;83:308‐315. - PubMed
    1. Ramezani A, Raj DS. The gut microbiome, kidney disease, and targeted interventions. J Am Soc Nephrol. 2014;25:657‐670. - PMC - PubMed
    1. Jernberg C, Lofmark S, Edlund C, Jansson JK. Long‐term impacts of antibiotic exposure on the human intestinal microbiota. Microbiology. 2010;156:3216‐3223. - PubMed
    1. Anders HJ, Andersen K, Stecher B. The intestinal microbiota, a leaky gut, and abnormal immunity in kidney disease. Kidney Int. 2013;83:1010‐1016. - PubMed
    1. Evenepoel P, Meijers BK, Bammens BR, et al. Uremic toxins originating from colonic microbial metabolism. Kidney Int Suppl. 2009;76:S12‐S19. - PubMed