Effects of Diet Price Tier and Nutrient Composition on Fecal Bacterial Microbiota in Healthy Adult Dogs: A cross-over study

Description

Consumer perception often assumes that high-priced commercial dry dog foods offer superior health benefits compared to budget alternatives, yet price tiers represent commercial marketing classifications rather than scientific standards. This study evaluated whether commercial dog food price tiers, including economy, standard, and premium, as well as their corresponding nutrient profiles, differentially affect fecal bacterial microbiota composition and digestive parameters in healthy adult dogs. Eight healthy adult mixed-breed dogs were enrolled in a crossover trial comparing representative economy, standard, and premium diets. Diets were evaluated for analytical chemical composition and in vitro pepsin digestibility. Fecal scores, feed intake, body weight, and body condition scores were recorded, and fecal bacterial microbiota were profiled using full-length 16S rRNA gene sequencing on the Oxford Nanopore platform. Body weight, body condition score, and feed intake did not differ significantly among dietary treatments (p > 0.05), and in vitro pepsin digestibility exceeded 80 percent. Fecal scores showed a significant diet effect (p = 0.02), with the economy diet producing higher scores than the premium diet (p < 0.05), though all diets maintained clinically ideal stool consistency with median scores of 2.0 to 2.5. Alpha diversity metrics did not differ across price tiers (p > 0.05). However, beta-diversity revealed distinct microbial clustering across dietary groups (PERMANOVA;R2 = 0.18, p < 0.001). Specific taxonomic shifts occurred at lower ranks, where economy diets enriched carbohydrate fermenting Catenibacterium (p < 0.05) whereas high protein premium diets increased the relative abundance of Terrisporobacter and Terrisporobacter mayombei (p < 0.05). Correlation analysis confirmed that fecal microbial shifts were driven primarily by specific nutrient parameters, notably dietary fiber fractions and crude protein concentrations, rather than retail price tier. In conclusion, commercial price tiers do not dictate overall gut microbial diversity or overall host digestive performance. Well-formulated, lower-tier grain-inclusive diets maintain ideal digestive function and a resilient gut microbiota comparable to premium grain-free formulations, demonstrating that canine dietary choices should be guided by balanced nutrient profiles rather than retail cost or marketing claims.

Institutions

• Kasetsart University

  Bangkok, Bangkok

Categories

Funders

• Faculty of Veterinary Medicine, Kasetsart University Bangkok, Thailand

  Grant ID: VET.KU2024-21
• Partially funded by the Faculty of Veterinary Medicine, Kasetsart University Bangkok, Thailand

  Grant ID: 67/15

Licence