Identificação de biomarcadores bacterianos de diagnóstico para câncer colorretal entre diferentes populações

Abstract

Colorectal cancer (CRC) is the fourth most lethal and occuring cancer worldwide, accounting for around 10% of diagnoses and deaths associated with cancer. New studies indicate that exposure to environmental risk factors and changes in the intestinal microbiota may be associated with the development of CRC. Imbalances in the microbiota can result in inflammation of the intestinal wall and a possible future progression to neoplasia. Using new sequencing methodologies, studies have found several genera and species significantly enhance or decrease in fecal samples compared between CRC patients and healthy individuals. Comparison of the microbiome of patients with CRC and healthy individuals allows the identification of important microbial biomarkers for neoplasms. Therefore, the present project had the general objective of identifying microbial biomarkers for prognosis present in the intestine of patients with colorectal cancer in different populations. Using publicly available 16S rDNA sequencing data from 11 projects from different countries, with stool samples from patients with colorectal cancer and controls from different laws. We discovered that there are microorganisms with different expression levels between the groups, and we found Ruminococcus bicirculans and Paracteroides merdae as biomarkers of healthy individuals, and Bacteroides stercoris and Bacteroides vulgatus as biomarkers of CRC patients. Furthermore, when a machine learning algorithm was used to identify which samples were healthy or had CRC, it had an efficacy of 92% and an AUC curve of 0.99. With the validation of these biomarkers, in the future it will be possible to detect the presence of these biomarkers in stool samples from individuals and diagnose cancer in initial projects, or which will directly impact patient survival.