Adhesion of Bacteroides vulgatus and Fusobacterium varium to the Colonic Mucosa of Healthy Beagles

The relative abundances of Bacteroidetes and Fusobacteria phyla have been reported to be decreased in dogs with chronic enteropathies. In colitis, obligate anaerobes (e.g., Bacteroides and Fusobacterium) are likely to vanish in response to the heightened oxidative stress in the colon’s inflammatory environment. The ability to adhere to the colonic mucosa is viewed as an essential step for obligate anaerobic bacteria to colonize and subsequently interact with the host’s epithelium and immune system. The reintroduction of a balanced community of obligate anaerobic bacteria using probiotics can restore the microbial function in the intestine. We found no studies on dogs regarding the adhesion properties of Bacteriodes vulgatus and Fusobacterium varium on paraffin-embedded canine colonic mucosa. Thus, the objective of this study is to investigate the adhesion capacities of these two bacterial species to paraffin-embedded colonic mucosa from healthy dogs. Additionally, we investigated their hydrophobicity properties to determine whether differences in adhesion capability can be explained by this factor. The results of our study showed that B. vulgatus adhered significantly lower than F. varium to the canine colonic mucosa (p = 0.002); however, B. vulgatus showed higher hydrophobicity (46.1%) than F. varium (12.6%). In conclusion, both bacteria have potential as probiotics, but further studies will be required to determine the efficacy and safety of the strains to be used, which strains to use, and the reasons other than hydrophobicity for attachment.