Longitudinal study of diet digestibility, microbiome, and gut fermentation metabolites in growing dogs.

Abstract

BACKGROUND: Puppies have particular characteristics due to gastrointestinal immaturity, influencing physiological processes. HYPOTHESIS/OBJECTIVES: Evaluate the effects of age and consumption on apparent diet digestibility coefficients (ADC), fecal characteristics, fermentation metabolites, and fecal microbiome in growing dogs. ANIMALS: Eight dogs were evaluated at 2, 5, 8, 11, and 14&#xa0;months old in experiment 1 and 12 dogs at 14&#xa0;months old in experiment 2. METHODS: This was a prospective experimental study. Dietary ADC, fecal characteristics, fermentation metabolites, and fecal microbiome were evaluated in 2 experiments: the first analyzed the effect of age, and the second, the effect of consumption in 2 groups: adult intake (AI) and puppy intake (PI). RESULTS: Older dogs had lower ADC of dry matter (DM), ether extract, and metabolizable energy, and higher ADC of crude protein (CP) (P&#xa0;<&#xa0;.05). Younger dogs had lower fecal DM and fecal score and higher fecal production (P&#xa0;<&#xa0;.05). Older dogs had higher fecal concentrations of short-chain fatty acids and indoles and lower concentrations of branched-chain fatty acids (BCFA) (P&#xa0;<&#xa0;.05). Dogs aged between 2 and 5&#xa0;months had a higher fecal abundance of Streptococcus and Escherichia coli and lower abundance of Turicibacter and Peptacetobacter (P&#xa0;<&#xa0;.05). The ADC of DM, organic matter, and CP were lower in PI dogs than in AI dogs (P&#xa0;<&#xa0;.05). The AI dogs had higher fecal DM and fecal score and lower fecal production (P&#xa0;<&#xa0;.05). Puppy intake dogs had higher fecal concentrations of ammonia and BCFA and a higher abundance of Streptococcus and a lower abundance of Blautia (P&#xa0;<&#xa0;.05). CONCLUSIONS AND CLINICAL IMPORTANCE: Age and feed intake influence the ADC of nutrients and energy, the fecal microbiome, and fermentation metabolites, with the microbiota stabilizing after 8&#xa0;months of age in dogs.