Chronic kidney disease in cats alters response of the plasma metabolome and fecal microbiome to dietary fiber

Abstract

The objectives were to determine the effects of feeding different fiber types to healthy cats and cats with chronic kidney disease (CKD) on plasma metabolites and the fecal microbiome. Methods A cross-over study within a split-plot design was performed using healthy (n = 10) and CKD cats [IRIS Stage 1 and 2; n = 10]. Cats were fed dry Prescription Diet ® k/d ® Feline with chicken, during a pre-trial period and then randomly assigned to two fiber treatments for 4 weeks each. Treatment foods were formulated similar to pre-trial food, with the exception that they contained 0.500% betaine, 0.586% oat beta glucan, and either 0.407% short chain fructooligosaccharides (scFOS) fiber or 3.44% apple pomace. Both foods had similar crude fiber percent (2.0 and 2.1% for scFOS and apple pomace, respectively) whereas soluble fiber was 0.8 and 1.6%, respectively.

Effect of Added Dietary Betaine and Soluble Fiber on Metabolites and Fecal Microbiome in Dogs with Early Renal Disease

“…Several studies have shown limited effects of consumption of increased whole plant foods, including fiber, on gut microbial composition in humans [ 47 ]. Of note, there were no significant differences between healthy dogs and those with CKD in the fecal microbiome at baseline, consistent with the few changes observed in a similar study on cats [ 6 ]. Thus, it appears that gut microbial composition in the early stages of CKD in cats or dogs is not substantially different from the healthy state.…”

“…All foods contained fiber from rice, barley, and sorghum as well as 4.9% beet pulp, with the amount of rice adjusted to accommodate for the added betaine, scFOS, and oat beta-glucan. All foods were in dry form and met the Association of American Feed Control Officials (AAFCO) maintenance nutrition requirements through testing, and dietary analysis was carried out as previously described [ 6 ].…”

“…Fecal microbiome data were processed as previously described [ 6 ]. Regression analyses using Pearson’s correlation coefficient (r) were used for correlations between plasma metabolites and serum creatinine and SDMA as well as for OTUs and metabolites.…”

“…In early stage CKD in dogs, treatment focuses on slowing the progression of the disease [ 5 ]. Cats with CKD have altered metabolite and microbiome profiles compared with healthy controls [ 6 ], and several metabolites have been characterized that lead to CKD progression in humans [ 7 ]. In CKD, dysbiosis of the intestinal microbiome and its uremic metabolites damage the intestinal epithelial tight junction and its barrier function [ 8 ], leading to the systemic inflammation and higher rates of cardiovascular disease that are hallmarks of CKD [ 9 , 10 ].…”

Changes in the Fecal Metabolome Are Associated with Feeding Fiber Not Health Status in Cats with Chronic Kidney Disease

“…The effects of feeding fiber to cats with CKD, as well as the best type of fiber to feed, have not been well studied. Because the type of fermentable fiber fed influences fecal microbial composition [10], we hypothesized that concentrations of microbiota-generated toxins and their precursor metabolites may be altered in the feces.…”