Characteristics of gallbladder microbiome in healthy dogs and cats, dogs with gallbladder mucocele, and cats with suspected cholangitis/cholangiohepatitis.

The aim of this study was to investigate and characterize the microbiome in bile samples obtained from dogs with gallbladder mucocele (6), cats with suspected cholangitis/cholangiohepatitis (4), as well as from healthy dogs (6) and cats (4). Our goal was to compare the microbiome patterns with clinical findings and bacterial culture results in diseases of the gallbladder and to identify a potential microbial biomarker of diseased groups. The microbial taxa composition revealed that Proteobacteria were the most dominant phylum in healthy and diseased individuals in all groups. Individuals from six families including Burkholderiaceae, Phyllobacteriaceae, Bradyrhizobiaceae, Sphingomonadaceae, Moraxellaceae, and Caulobacteraceae, constituted the core microbiome in the gallbladder of healthy dogs. A combination of LEfSe analysis and Taxa2ASV decomposer revealed that Pseudomonaceae and Ruminococcaceae exclusively occurred in the mucocele group. In conclusion, this study determined the core microbiome in the gallbladder of healthy dogs and the possible biomarkers (Pseudomonaceae and Ruminococcaceae) of gallbladder mucocele in dogs.