Microbiomes in Human Pancreatic Cancer. Homo sapiens

Background: Data from numerous prospective cohort studies consistently support an association between periodontal disease, periodontal disease pathogens, and pancreatic cancer risk. To date, it is not known if periodontal pathogens are present in the normal pancreas or in pancreatic tumors, and if the bacterial profiles vary by site or disease phenotype. 77 patients requiring surgery for pancreatic diseases, or other diseases of the foregut, were recruited into this study from the Rhode Island Hospital. For each patient, multiple tissue and/or swab specimens were obtained during surgery. In addition, 36 whole pancreas were obtained from the National Disease Research Interchange from subjects who were of similar age as the RIH patients and had not died of cancer. The primary exposure of interest was the relative abundance of bacterial taxa in the tissue and swab specimens obtained from 16S rRNA gene sequencing.Results: Number of bacterial reads per tissue or swab sample varied substantially across patients, but all demonstrated the presence of diverse bacteria, including a number of bacterial taxa typically identified in the oral cavity. Comparing the mean relative abundance of bacterial taxa in pancreatic cancer patients to those without cancer revealed differences in bacterial taxa previously linked to periodontal disease. Both bacterial taxa known to inhabit the oral cavity and the large intestine were identified in pancreatic tissue of cancer and non-cancer subjects.