Domestic canines do not display evidence of gut microbial dysbiosis in the presence of Clostridioides (Clostridium) difficile, despite cellular susceptibility to its toxins

The Role of the Canine Gut Microbiome and Metabolome in Health and Gastrointestinal Disease

“…C. difficile strains isolated from dogs are capable of producing toxins in vitro that severely impair tight junctions in canine and human cell lines (75). Authors have speculated that, similarly to humans, the presence of bile acid dehydroxylating bacteria, specifically Clostridium hiranonis, can be a protecting factor in dogs.…”

“…Authors have speculated that, similarly to humans, the presence of bile acid dehydroxylating bacteria, specifically Clostridium hiranonis, can be a protecting factor in dogs. In addition, Sphingobacterium faecium was also suggested as a protective species, which could be associated with its sphingophospholipid production abilities (75).…”

Prevalence, Colonization, Epidemiology, and Public Health Significance of Clostridioides difficile in Companion Animals

“…The pathogenesis and clinical features of CDI in companion animals appear to be strikingly different from that of human CDI. Gut dysbiosis is not a significant feature of CDI in dogs ( 26 , 38 ), despite being a major factor in the pathogenesis of CDI in humans. Clinical signs such as acute hemorrhagic diarrhea in C. difficile infected dogs do not significantly correlate with the presence of C. difficile in the gut ( 27 , 39 ).…”

“…Additionally, the absence of dysbiosis suggests other potential causes or predisposing factors for CDI. Comparative microbiome analysis revealed a marked increase in the abundance of Fusobacteria, Proteobacteria , and Firmicutes , and a decrease in Verrucomicrobia, Bacteroidetes, Euryarchaeota , and Actinobacteria in C. difficile -carrying dogs, whereas, in humans infected with C. difficile , decreases in the abundance of Firmicutes, Actinobacteria , and Euryarchaeota were reported ( 38 ). Therefore, the abundance of Firmicutes could be a significant factor potentially associated with a lack of clinical symptoms in C. difficile positive dogs with dysbiosis ( 38 ).…”

“…Comparative microbiome analysis revealed a marked increase in the abundance of Fusobacteria, Proteobacteria , and Firmicutes , and a decrease in Verrucomicrobia, Bacteroidetes, Euryarchaeota , and Actinobacteria in C. difficile -carrying dogs, whereas, in humans infected with C. difficile , decreases in the abundance of Firmicutes, Actinobacteria , and Euryarchaeota were reported ( 38 ). Therefore, the abundance of Firmicutes could be a significant factor potentially associated with a lack of clinical symptoms in C. difficile positive dogs with dysbiosis ( 38 ). Notably, Clostridial and Eubacteria species, part of the Firmicutes phylum, possess the ability to convert primary bile acids into secondary bile acids predominantly by 7α-dehydroxylation ( 42 ).…”