PSIX-12 Influence of obesity on satiety hormones, serum metabolome, and fecal microbiome in adult dogs

Abstract The objective of this study was to investigate the difference between lean and obese dogs in terms of their satiety hormones, serum metabolome, and fecal microbiome. Mixed-breed lean (n = 30; 17 male and 13 female; 4.0 ± 2.5 yr of age; 24.6 ± 6.3% body fat) and obese (n = 30; 19 male and 11 female; 7.3 ± 2.1 yr of age; 46.9 ± 3.9% body fat) adult dogs were used in this study. Blood samples were collected to measure satiety hormones and serum metabolome, and fresh fecal samples were collected for microbiome analysis. It was hypothesized that obese dogs had altered metabolism and gut microbiome compared with lean dogs. Data were analyzed using MIXED procedure of SAS, using body type as the fixed effect and dog as the random effect. Results showed that obese dogs had greater (P < 0.05) serum leptin, insulin, and insulin-like growth factor-1 (IGF-1) concentrations, but reduced (P < 0.05) gastric inhibitory peptide (GIP) than lean dogs. Serum concentrations of all essential amino acids except for threonine in obese dogs were greater (P < 0.05) than in lean dogs. Obese dogs also had greater (P < 0.05) concentrations of serum N-Lactoyl amino acids and dipeptides except for prolylglycine than their lean counterparts. Additionally, concentrations of serum long-chain saturated and monounsaturated fatty acids were less (P < 0.05; only for myristate, pentadecanoate, and non-adecanoate) or similar in obese dogs compared with lean dogs. Serum oxidative stress makers, such as oxidized glutathione, cysteine-glutathione, and 4-hydroxynonenal, were greater (P < 0.05) in obese dogs than lean dogs. Furthermore, obese dogs had less (P < 0.05) fecal Firmicutes, but greater (P < 0.05) fecal Bacteroidetes and Fusobacteria, compared with lean dogs. There were no differences (P > 0.10) in fecal microbiome alpha diversity, such as Chao1 and Shannon index, between lean and obese dogs. In conclusion, obese dogs had differential body metabolism and gut microbiome compared with lean dogs.