PSV-3 Impacts of rotational ingredient supplementation on canine gastrointestinal microbiota upon exposure to rapid dietary change.

Abstract Rapid dietary changes have been reported to disrupt gastrointestinal health, but there is limited data on effective mitigation strategies. The objective of this study was to assess the impact of increased dietary diversity in response to an abrupt dietary transition as measured by short-chain fatty acid (SCFA) concentrations and microbial composition. Labrador retrievers (n = 16) aged 1-3 yo, BCS (5-6), enrolled in detection dog training and receiving daily conditioning and exercise, participated in a 120-day study. Dogs were enrolled into one of two treatment groups. Control dogs (CON) received a single basal diet, while rotational ingredient dogs (ROT) received the same basal diet with rotating supplemental ingredients (2.5% of total daily DM intake) over 90 days, including oatmeal, blueberries, pumpkin, beef liver, salmon, and rabbit. Following a 30-day acclimation period, both groups underwent a rapid, untransitioned dietary change (dietary challenge) for two meals (am/pm feedings) on days 0, 45, and 90. Fecal samples were collected across three consecutive days for each testing period beginning at d0, 45, and 90 and analyzed for SCFA concentrations and microbial composition. Statistical analysis was conducted using SAS (v 9.4) with significance set at 5%. Concentrations of SCFA were impacted across both treatment groups following the dietary challenge. All dogs experienced increased concentrations of butyric acid (P = 0.0015) and propionic acid (P = 0.0209) following the dietary challenge. Conversely, isovaleric (P = 0.0038) and isobutyric acid (P = 0.0027) were decreased following dietary challenge. Interestingly, concentrations of propionic acid increased throughout the study for all dogs (P = 0.0038). Analysis of the microbial composition revealed beneficial impacts of rotational ingredient supplementation including an increase in Faecalibacterium (P = 0.01) and Streptococcus (P = 0.04) as well as a reduction in E. coli (P = 0.023). Inclusion of dietary challenge increased levels of Turicibacter (P = 0.01), Streptococcus (P = 0.003), Blautia (P = 0.002), and C. hiranonis (P = 0.01). The recovery meal resulted in increased concentrations of Fusobacterium (P < 0.001) and Faecalibacterium (P < 0.0001). These findings suggest that while rotational ingredient supplementation did not significantly affect SCFA concentrations, there were significant benefits within the microbial profile including an increase in beneficial bacteria such as Faecalibacterium, along with reduced numbers of pathogens such as E. coli. Interestingly, the dietary challenge prompted changes including increased concentrations of butyric acid and propionic acid which may indicate a potential anti-inflammatory response of the gastrointestinal tract following abrupt dietary transitions. These findings provide further evidence to support dietary diversity as a method for improving gastrointestinal health and diversity. Future research is needed to determine guidelines and practices for rotational diets and other ingredients that may be used for improving gut health.