Effects of a Veterinary Gastrointestinal Low-Fat Diet on Fecal Characteristics, Metabolites, and Microbiota Concentrations of Adult Dogs Treated with Metronidazole

The objective of this study was to determine how a veterinary gastrointestinal low-fat diet impacts the fecal characteristics, metabolites, and microbiota concentrations of adult dogs treated with metronidazole. All dogs were fed a control diet during a 2-week baseline, dosed orally with metronidazole (20 mg/kg BW) from weeks 2-4, then randomly allotted to 1 of 2 treatments (control diet or veterinary diet). Fecal scores were recorded and fresh fecal samples were collected over time to assess fecal characteristics, microbiota populations, and BA concentrations. Metronidazole increased fecal scores (looser stools) and drastically alter the fecal microbiota populations (altered diversity measures and more than 50 bacterial taxa) in addition to bile acid profiles (increased primary and reduced secondary profiles). Majority of recovery was observed in as little as one week post-administration. In dogs fed BB, SCFA and IgA concentrations were higher (P<0.01), while fecal BCFA, phenol, and indole concentrations were lower (P<0.05). BA profiles were largely unaffected in both treatment, except for LCA, which was lower (P<0.0001) in dogs fed BB. While most variables returned to pre-antibiotic levels with time, these results demonstrate that a specially formulated veterinary diet may aid in the recovery of many important microbial markers of GI stability.