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

## TL;DR

This study examines how age and food intake affect digestion, gut microbes, and fermentation in growing dogs.

## Contribution

The study provides new insights into how the gut microbiome and digestion change with age and diet in puppies.

## Key findings

- Older dogs had lower digestibility of dry matter and higher protein digestibility.
- Puppies had more unstable gut microbiomes, which stabilized after 8 months.
- Higher food intake in puppies altered fermentation metabolites and microbial abundance.

## Abstract

Puppies have particular characteristics due to gastrointestinal immaturity, influencing physiological processes.

Evaluate the effects of age and consumption on apparent diet digestibility coefficients (ADC), fecal characteristics, fermentation metabolites, and fecal microbiome in growing dogs.

Eight dogs were evaluated at 2, 5, 8, 11, and 14 months old in experiment 1 and 12 dogs at 14 months old in experiment 2.

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).

Older dogs had lower ADC of dry matter (DM), ether extract, and metabolizable energy, and higher ADC of crude protein (CP) (P < .05). Younger dogs had lower fecal DM and fecal score and higher fecal production (P < .05). Older dogs had higher fecal concentrations of short-chain fatty acids and indoles and lower concentrations of branched-chain fatty acids (BCFA) (P < .05). Dogs aged between 2 and 5 months had a higher fecal abundance of Streptococcus and Escherichia coli and lower abundance of Turicibacter and Peptacetobacter (P < .05). The ADC of DM, organic matter, and CP were lower in PI dogs than in AI dogs (P < .05). The AI dogs had higher fecal DM and fecal score and lower fecal production (P < .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 < .05).

Age and feed intake influence the ADC of nutrients and energy, the fecal microbiome, and fermentation metabolites, with the microbiota stabilizing after 8 months of age in dogs.