The effect of lyophilised oral faecal microbial transplantation on functional outcomes in dogs with diabetes mellitus

Objectives: We aimed to determine if oral faecal microbiota transplantation improves indices of glycaemic control, changes the faecal dysbiosis indices, alters faecal short-chain fatty acid and bile acid profiles and increases serum glucagon-like-peptide 1 concentrations in diabetic dogs. Materials and Methods: In this prospective randomised, placebo-controlled, double-blinded pilot study, we recruited nine diabetic dogs (five faecal microbiota transplantation and four placebo) and nine healthy controls. Results: Compared to healthy dogs, diabetic dogs had altered faecal short-chain fatty acid and bile acid profiles. In the first 30 days, the faecal microbiota transplantation group had a more rapid decline in interstitial glucose; however, the mean interstitial glucose of the faecal microbiota transplantation recipients did not differ from the placebo recipients at the end of the study. Compared with placebo, faecal microbiota transplantation recipients had a decreased 24-hour water intake at day 60 and increased faecal abundance of Faecalibacterium. Clinical Significance: This study provides a proof of concept for faecal microbiota transplantation in canine diabetes, and its data could inform the design of future large-scale studies. Further investigation is required to determine whether faecal microbiota transplantation would have any role as an adjunctive therapy in canine diabetes and to elucidate the mechanisms by which faecal microbiota transplantation may provide a beneficial clinical effect in canine diabetes.