Cats increase lean body mass with carnitine or carnosine but not with the combination

Abstract

This study evaluated whether dietary carnitine or carnosine would change lean body mass, circulating cytokines or metabolites in cats. All study protocols were reviewed and approved by the Institutional Animal Care and Use Committee, Hill's Pet Nutrition, Inc., Topeka, KS. Forty four pets were assigned into four groups: Group 1 (n=11) was fed the control diet, group 2 (n=11) was fed the control diet + L‐carnitine (0.03%), group 3 (n=12) was fed the control diet + L‐carnosine (0.1%), and Group 4 (n=10) was fed the Control diet + L‐carnitine + L‐carnosine. The ages of the cats ranged from 7.2 to 13.9 yr. The duration of the study was 6 months. Initial body composition, cytokines and metabolomics profiles were compared to final and changes were compared across treatments. Metabolomics were measured by Metabolon (Morrisville, NC), cytokines were measured by ELISA. Change in lean body mass (LBM) was assessed by Dual‐energy X‐ray absorptiometry (DEXA) and reported in cats as the difference in LBM between initial and final times. Changes in analytes were then compared amongst the 4 groups. Serum levels of cytokines assessed included Flt‐3L, IFN‐γ, IL12p40, IL‐4, IL‐6, IL‐8, IL‐13, IL‐18, and MCP‐1. Modest reductions were observed in the levels of selected cytokines on day 169 when compared to the baseline but these changes were not significant between groups. Lean body mass results showed that cats fed either carnitine alone (+106 g) or carnosine alone (+96 g) had increased lean when compared to control cats or cats supplemented with both carnitine and carnosine (p<0.01). There was no statistical difference between treatments in either body weight or body fat change. Carnitine and deoxycarnitine were increased in the group that had carnitine alone (p<0.05) while many acyl carnitines were increased in both groups supplemented with carnitine. Carnosine was not changed but beta‐alanine was increased in cats fed carnosine. The metabolism of aromatic amino acids (phenylalanine, tyrosine, and tryptophan and dietary polyphenolic compounds) occurs, in part, through the involvement of enzymes encoded within the microbiome. Several microbiota‐derived‐metabolites were higher in Groups 2, 3, and 4 when compared to Group 1 at various time points. These data indicate that supplementation of carnitine or carnosine is beneficial in increasing LBM in felines but that when combined they do not influence LBM.Support or Funding InformationThis study was funded by Hill's Pet Nutrition Inc.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.