Characterization of the fecal and mucosa-associated microbiota in dogs with colorectal epithelial tumors

Abstract

Colorectal epithelial tumors occur spontaneously in dogs, and the pathogenesis seems to parallel that of humans. The development of human colorectal tumorigenesis has been linked to alterations in the composition of the intestinal microbiota. This study characterized the fecal- and mucosa-associated microbiota in dogs with colorectal epithelial tumors (n = 10). The fecal microbiota was characterized by 16S rDNA analysis and compared with that of control dogs (n = 13). We also determined the mucosa-associated microbiota composition in colonic tumor tissue (n = 8) and in adjacent non-tumor tissue (n = 5) by 16S rDNA- and rRNA profiling. The fecal microbial community structure in dogs with tumors was different from that of control samples and was distinguished by oligotypes affiliated with Enterobacteriaceae, Bacteroides, Helicobacter, Porphyromonas, Peptostreptococcus and Streptococcus, and lower abundance of Ruminococcaceae, Slackia, Clostridium XI and Faecalibacterium. The overall community structure and populations of mucosal bacteria were not different based on either the 16S rDNA or the 16S rRNA profile in tumor tissue vs. adjacent non-tumor tissue. However, the proportion of live, potentially active bacteria appeared to be higher in non-tumor tissue compared with tumor tissue and included Slackia, Roseburia, unclass. Ruminococcaeceae, unclass. Lachnospiraceae and Oscillibacter. Colorectal tumors are rarely diagnosed in dogs, but despite this limitation, we were able to show that dogs with colorectal tumors have distinct fecal microbiota profiles. These initial results support the need for future case-control studies that are adequately powered, as well as age-matched and breed-matched, in order to evaluate the influence of bacteria on colorectal cancer etiopathogenesis and to determine whether the bacteria may have potential as biomarkers in clinical settings.

Electroporation-Based Treatments in Small Animal Veterinary Oral and Maxillofacial Oncology

“…This phenomenon could be of a great importance in implementing personalized therapeutic protocols ( 108 ). In dogs, a difference in intestinal microbiota composition has been reported between those with colorectal epithelial tumors ( 109 ) or lymphoma ( 110 ) and healthy individuals. However, there is currently no information on peripheral solid tumors and the role played by the gastrointestinal microbiota in the response to immunotherapy in dogs.…”

Characterization of Lactobacillus rhamnosus MP01 and Lactobacillus plantarum MP02 and Assessment of Their Potential for the Prevention of Gastrointestinal Infections in an Experimental Canine Model

“…To estimate the concentration of lactobacilli and enterobacteria, appropriate dilutions were spread in triplicate onto MRS-Cys agar plates (for lactobacilli), and MacConkey (MCK; Biomerieux) agar plates (for enterobacteria). MRS-Cys plates were incubated in anaerobiosis and MCK agar plates in aerobiosis; all the plates were incubated at 37°C for 48 h. Quantitative real-time PCR (qPCR) assays were performed for Faecalibacterium spp., since previous studies have found that this genus is considered as a marker of good canine gut health (Herstad et al, 2018). Initially, a fraction of the fecal samples was centrifuged at 13,000 rpm for 20 min.…”

Review: Other Helicobacter species

“…32 Proliferative and invasive colorectal tumors were investigated in 20 pet dogs. 34 A species rarely reported in dogs, "Helicobacter winghamensis," was isolated from fecal samples of working farm dogs. 33 These findings provide unique insight into human CRC since human CRC molecular characteristics match those of canine tumors.…”

“…A further study has shown that Enterobacteriaceae and Helicobacter belong to the microbiota of dogs with colorectal tumors. 34 A species rarely reported in dogs, "Helicobacter winghamensis," was isolated from fecal samples of working farm dogs. 35 Enterobacteriaceae dominated the gut microbial compositions in adult giant pandas and their cubs while Helicobacteraceae belonged to the seven genera that showed great importance with respect to gut microbial structural determination in the nursing stage of giant panda cubs.…”