Methods: This was a cross-sectional study. Dietary histories were obtained, and macronutrient intake (g/100 kcal protein, fat, and crude fiber), commercial diet brand, and dietary diversity (number of unique food sources) were recorded. Microbial DNA was extracted from urine collected via cystocentesis, and V4 amplicon sequencing of the bacterial 16S rRNA gene was performed. Data were analyzed to determine how variation in macronutrients and dietary sources contributed to urobiome alpha diversity, beta diversity, and individual taxa abundance.
Results: Macronutrient content was not found to effect alpha or beta diversity. Bray Curtis measure of beta diversity differed (R2 = .10, P = .017) between dogs fed one commercial diet brand compared to dogs consuming any other brand, characterized by lower alpha diversity (P = .018) and lower relative abundances Staphylococcus, Bacillus halodurans, and Paracoccus. Beta diversity also differed (R2 = .10, P = .019) between dogs consuming more diverse daily diets (≥ 3 unique food sources) as compared to those consuming less diverse diets.
Conclusions and clinical importance: Due to overlap between diet brand and dietary diversity groups, it is unclear whether one or both variables drove urobiome differences. Overall, the results of this study suggest that diet might impact the urobiome in dogs.
