The objective of this study was to determine the fecal characteristics, microbiota, and metabolites of dogs fed a Saccharomyces cerevisiae fermentation product (SCFP) and subjected to exercise challenge in untrained and trained states. Thirty-six adult dogs were randomly assigned to control or SCFP-supplemented (250 mg/d) diets and fed for 10 wk. An exercise challenge was administered while dogs were in an untrained state and a trained state (after 7 wk of an exercise regimen), with fresh fecal samples collected pre- and post-challenge. Exercise challenge reduced fecal pH and ammonia in all dogs. After the exercise challenge in untrained dogs, fecal indole, isobutyrate, and isovalerate concentrations were reduced, while acetate and propionate concentrations were increased. Following exercise challenge in trained dogs, fecal scores and butyrate concentrations decreased, while isobutyrate and isovalerate increased. SCFP reduced fecal Clostridium over time vs. controls. Beta diversity analysis revealed clustering of dogs before and after exercise in trained dogs. After exercise challenge, over 10 bacterial genera were altered in untrained and trained dogs. Our findings show that exercise and SCFP may affect the fecal microbiota of dogs, but exercise was the primary cause of the shifts and trained dogs had more profound changes than untrained dogs.

Read the full article in the Journal of Animal Science.