Fecal microbiota transplants modulate the gut microbiome of a two-toed sloth (Choloepus didactylus).

The microbes inhabiting an animal's gastrointestinal tracts, collectively known as the gut microbiome, are vital to animal health and wellbeing. For animals experiencing gut distress or infection, modulation of the gut microbiome, for example, via fecal microbiota transplant (FMT), provides a possible disease prevention and treatment method. The beneficial microbes present in the donor's transplanted feces can help combat pathogens, assist in digestion, and rebalance the recipient's microbiota. Investigating the efficacy of FMTs in animal health is a crucial step toward improving management strategies for species under human care. We present a case study of the use of FMTs in a two-toed sloth experiencing abnormally large, clumped, and frequent stools. We used 16 S rRNA amplicon sequencing of fecal samples to (a) compare the microbiomes of the FMT donor, a healthy, cohoused conspecific, and the FMT recipient and (b) assess the influence of multiple rounds of FMTs on the recipient's microbiome and stool consistency and frequency over time. In response to the FMTs, we found that the recipient's microbiome showed trends toward increased diversity, shifted community composition, and altered membership that more resembled the community of the donor. FMT treatment was also associated with marked, yet temporary, alleviation of the recipient's abnormal bowel movements, suggesting a broader impact on gut health. Our results provide valuable preliminary evidence that FMT treatments can augment the recipient's gut microbiome, with potential implications for animal health and management.