Table 1.

Relative fecal metabolite concentrations for antioxidants, markers of oxidation and inflammation, methylated metabolite, TCA cycle, and urea cycle intermediates in healthy cats (H cats) and chronic kidney disease (CKD) cats at baseline (after feeding pretrial food ¹ for 14 days) and after feeding food A ² (containing scFOS) or food B ³ (containing apple pomace) as fiber sources for 4 weeks each.

	Mean Values *						Group Effect ‡
	H Cats			CKD Cats			Overall Effect of Health	Overall Effect of Both Treatments	H Cats: Effect of Treatment with Food B versus Food A ¥	CKD Cats: Effect of Treatment with Food B versus Food A ¥	Overall Effect of Interaction
Metabolites	BSL #	Food A	Food B	BSL #	Food A	Food B	P-Value	P-Value	P-Value	P-Value	P-Value
Tocopherol Metabolism
alpha-tocopherol	1.11	1.00 §	0.94 §	1.03	0.99	0.93 §	0.39	0.000	0.02	0.08	0.06
alpha-tocopherol acetate	0.94	1.09	0.89	0.83	1.02 §	1.01	0.86	0.02	0.01	0.85	0.14
delta-tocopherol	1.31	0.97 §	0.88 §	1.23	0.96 §	0.94 §	0.91	0.000	0.02	0.74	0.09
alpha-tocotrienol	1.21	0.85 §	1.02 §	1.20	0.90 §	1.07	0.56	0.000	0.003	0.000	0.26
gamma-tocotrienol	1.37	0.79 §	0.85 §	1.37	0.90 §	1.00 §	0.30	0.000	0.42	0.02	0.16
gamma-CEHC	1.51	1.20 §	1.04 §	0.93	0.67	0.68	0.04	0.01	0.69	0.78	0.66
alpha-CEHC sulfate	0.94	1.04	1.33 §	0.63	0.64	0.88	0.15	0.03	0.13	0.66	0.68
alpha-CEHC	1.52	1.45	0.96 §	0.97	0.83	0.59	0.10	0.01	0.02	0.23	0.71
gamma-tocopherol/beta-tocopherol	1.80	0.90 §	0.97 §	1.67	0.88 §	1.02 §	0.62	0.000	0.04	0.000	0.02
Glutathione Metabolism
cysteinylglycine	0.94	0.78	0.99	1.29	0.75 §	1.00 §	0.61	0.000	0.02	0.01	0.01
5-oxoproline	1.59	1.80	1.61	1.49	1.19	1.79	0.30	0.53	0.63	0.22	0.43
2-hydroxybutyrate/2-hydroxyhydroxyisobutyrate	0.86	1.25	1.38	0.86	0.93	1.85	0.66	0.04	0.91	0.04	0.31
Sphingolipid Metabolism
sphinganine	1.85	1.09 §	1.04 §	1.09	1.01	0.80	0.04	0.000	0.82	0.49	0.02
sphingosine	1.52	0.99 §	0.96 §	1.14	1.06	0.90	0.47	0.002	0.81	0.65	0.10
sphingadienine	1.11	0.93 §	1.05	1.08	0.94 §	1.07	0.94	0.000	0.03	0.004	0.57
Glycine, Serine, and Threonine Metabolism
glycine	0.90	1.20 §	1.49 §	0.84	0.78	0.85	0.01	0.003	0.08	0.36	0.01
sarcosine	0.96	1.03	1.20	0.85	0.77	1.02	0.18	0.53	0.49	0.59	0.96
dimethylglycine	1.06	1.38 §	1.36 §	0.80	1.11	1.49 §	0.27	0.01	0.99	0.57	0.81
betaine	0.93	1.82 §	2.56 §	0.58	0.64	1.20 §	0.003	0.000	0.14	0.01	0.08
TCA Cycle
citrate	0.90	1.24	1.63	0.94	0.89	1.01	0.18	0.43	0.76	0.46	0.52
alpha-ketoglutarate	0.91	1.79	1.19	0.98	1.04	1.69 §	0.99	0.08	0.50	0.09	0.23
succinate	1.28	1.14	1.54	1.11	0.83	0.89	0.01	0.48	0.22	0.70	0.41
fumarate	1.49	1.00	0.89	1.54	1.25	1.35	0.72	0.27	0.75	0.56	0.44
malate	1.30	1.32	1.58	0.89	1.22	1.25	0.23	0.13	0.28	0.78	0.83
Urea Cycle
arginine	0.53	1.46 §	1.35 §	0.59	0.85	0.87	0.06	0.001	0.75	0.67	0.02
argininosuccinate	0.10	0.55	0.33	0.11	0.45	0.52	0.97	0.13	0.98	0.92	0.95
ornithine	1.21	1.21	1.06	1.08	1.11	0.99	0.23	0.65	0.42	0.74	0.78
citrulline	1.14	0.98	0.93 §	1.07	1.03	0.93	0.98	0.05	0.68	0.29	0.62
Valine, Arginine, and Proline Metabolism
norvaline	0.72	2.34 §	2.57 §	0.79	1.44 §	1.26	0.11	0.000	0.86	0.35	0.09
2-oxoarginine	0.64	1.68 §	1.32 §	0.59	1.09 §	1.45 §	0.23	0.000	0.46	0.21	0.18
homocitrulline	0.85	1.11 §	1.04 §	0.98	1.59 §	1.34 §	0.42	0.000	0.79	0.99	0.15
proline	1.05	1.23	1.37 §	1.35	0.88 §	1.12 §	0.46	0.06	0.33	0.12	0.001
dimethylarginine (SDMA+ADMA)	0.81	1.12 §	1.11 §	0.99	1.06	1.11	0.89	0.005	0.98	0.66	0.03
N-acetylarginine	0.80	1.24 §	1.14 §	0.86	1.04	0.98	0.34	0.02	0.64	0.55	0.20
N-acetylcitrulline	0.77	1.21 §	1.15 §	0.85	1.03	0.93	0.30	0.01	0.64	0.50	0.42
N-acetylproline	1.60	0.82 §	0.82 §	1.62	0.76 §	0.71 §	0.59	0.000	0.94	0.72	0.50
N-delta-acetylornithine	1.11	1.01	0.96	1.06	0.88	1.20	0.42	0.61	0.86	0.37	0.49
N-alpha-acetylornithine	1.24	1.17	0.98	1.14	0.93	0.85 §	0.10	0.01	0.17	0.51	0.68
N-methylhydroxyproline	0.86	0.86	0.89	0.99	0.88	1.07	0.33	0.40	0.50	0.23	0.91
trans-4-hydroxyproline	0.75	1.31 §	1.17 §	0.98	0.99	1.08	0.32	0.10	0.58	0.66	0.03
N-methylproline	1.70	1.60	0.63 §	1.68	1.47	0.75	0.94	0.002	0.001	0.16	0.38
N-monomethylarginine	0.82	0.78	1.17 §	1.08	0.90	1.11	0.44	0.02	0.002	0.41	0.07
argininate	1.05	1.33	1.70 §	0.86	0.82	0.93	0.01	0.20	0.18	0.59	0.11

¹ Baseline (BSL; pre-trial) food was a complete and balanced dry food designed to aid in the management of renal disease. ² Food A was prepared by Hill’s Pet Nutrition, Inc. and was similar to the pre-trial food, with the exception that it was supplemented with betaine (0.500%), oat beta glucan (0.586%), and 0.407% short chain FOS (scFOS). ³ Food B was prepared by Hill’s Pet Nutrition, Inc. and was similar to the pre-trial food, with the exception that it contained 0.500% betaine, 0.586% oat beta glucan, and 3.44% apple pomace. * For each metabolite, mean value is the group mean of re-scaled data to have median equal to 1. ^‡ A mixed model was used with cat identity as random effect to test whether means were different based on health status of cats (healthy versus CKD), type of fiber fed (scFOS versus apple pomace), or an interaction between health status and type of fiber fed. ^¥ The mixed model was used to test whether means were different after treatment with apple pomace versus scFOS as a fiber source within healthy cats and within CKD cats. ^# The mixed model was used to test whether means were different at baseline based on health status of cats (healthy versus CKD). There were no differences. ^§ The mixed model was used to test whether the difference of two paired observations from a single cat at baseline and the end of the 4 week feeding period was different than zero. Significance was established when P ≤ 0.05 (for type 1 error) and q ≤ 0.1 (q-values were used to estimate false discovery rate in multiple comparisons.