Simultaneous Daily Fecal Microbiota Transplantation Fails to Prevent Metronidazole-Induced Dysbiosis of Equine Gut Microbiota.
Authors: Kinoshita Yuta, Niwa Hidekazu, Uchida-Fujii Eri, Nukada Toshio, Ueno Takanori
Journal: Journal of equine veterinary science
Summary
# Editorial Summary Metronidazole, whilst valuable for treating certain equine infections, can severely disrupt the intestinal microbiota and precipitate secondary diarrhoea or enteritis. Researchers investigated whether simultaneous faecal microbiota transplantation (FMT) could prophylactically protect against this dysbiosis, comparing metronidazole-treated horses with and without concurrent daily FMT (500 g donor faeces suspended in 1 L) using metagenomic analysis to track bacterial family composition. Both groups experienced comparable dysbiotic shifts—particularly in Clostridiaceae, Ruminococcaceae, and Enterobacteriaceae populations—with metronidazole treatment accounting for the observed changes (P = .0003) rather than FMT providing any protective effect (P = .3136). The current FMT protocol proved ineffective at prevention, suggesting that dose, frequency, delivery method, or donor selection requires optimisation before FMT can reliably mitigate antimicrobial-induced dysbiosis in equine practice. For practitioners managing horses requiring metronidazole therapy, this finding underscores the need for alternative prophylactic strategies—such as probiotics, prebiotics, or modified FMT protocols—whilst highlighting that standard FMT protocols cannot presently be relied upon to prevent metronidazole-related complications.
Read the full abstract on PubMed
Practical Takeaways
- •FMT administered simultaneously with metronidazole at standard doses (500 g/day) does not protect horses from antibiotic-induced dysbiosis—practitioners cannot rely on concurrent FMT as preventive strategy during metronidazole therapy
- •If FMT is to be considered for dysbiosis prevention, alternative protocols with higher doses, increased frequency, or delayed timing post-antimicrobial should be explored before implementation in practice
- •Clinicians should focus on other dysbiosis management strategies when antimicrobials are necessary, as current evidence does not support simultaneous FMT as an effective prophylactic intervention
Key Findings
- •Simultaneous FMT at 500 g donor feces once daily did not prevent metronidazole-induced dysbiosis in horses
- •Metronidazole administration caused significant changes in bacterial families (Clostridiaceae, Ruminococcaceae, Enterobacteriaceae) regardless of FMT treatment (P = 0.0003)
- •FMT alone had no statistically significant effect on fecal bacterial composition changes (P = 0.3136)
- •Current FMT protocol and dosing require improvement to be effective as prophylaxis against antimicrobial-induced dysbiosis