(GI31) Description and Insights of the Feline and Canine Gut Mycobiome

Abstract: Background - The gut mycobiome plays a vital role in maintaining the health and well-being of cats and dogs. However, little is known about the composition and diversity of the feline and canine gut mycobiomes, especially at the full-length ITS level. Objectives - This study characterized the gut mycobiome of cats and dogs using full-length ITS sequencing of fecal samples. Methods - 670 canine fecal samples (297 customer submissions with no conditions, 346 customer submissions with gut, skin or oral issues, and 27 healthy donors) and 139 feline fecal samples (57 customer submissions with no conditions, 65 customer submissions with gut, skin or oral issues, and 17 healthy donors) were sequenced for full-length ITS. Results - Cladosporium herbarum, Cyphellophora reptans, Cyniclomyces guttulatus, Issatchenkia orientalis, Saccharomyces cerevisiae, Candida albicans, Malassezia pachydermatis, and Trichosporon asaahii were the most abundant fungi in dogs. In cats, the main taxa were Cyniclomyces guttulatus, Saccharomyces cerevisiae, Cyphellophora reptans, Cryptococcus neoformans, Clitopilus baronii, and Sarocladium dejongiae. We found no difference in alpha diversity between healthy and customer-derived samples from both cats and dogs. Furthermore, a comparative analysis was performed on samples subjected to both 16S and ITS sequencing. The mycobiome's Shannon index was lower in healthy subjects and higher in those with undetermined health. The opposite trend was seen in bacterial community composition. Conclusions - Although limited by a relatively small sample size, this study provides new insights into the composition and diversity of feline and canine gut mycobiomes. Further research is needed for a comprehensive understanding.