AUTHOR=Grion Beatriz Alessandra Rudi , Fonseca Paula Luize Camargos , Kato Rodrigo Bentes , García Glen Jasper Yupanqui , Vaz Aline Bruna Martins , Jiménez Beatriz Nafría , Dambolenea Ainhoa Lapitz , Garcia-Etxebarria Koldo , Brenig Bertram , Azevedo Vasco , Bujanda Luis , Banales Jesus M. , Góes-Neto Aristóteles 

TITLE=Identification of taxonomic changes in the fecal bacteriome associated with colorectal polyps and cancer: potential biomarkers for early diagnosis

JOURNAL=Frontiers in Microbiology

VOLUME=14

YEAR=2024

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2023.1292490

DOI=10.3389/fmicb.2023.1292490

ISSN=1664-302X

ABSTRACT=<p>Colorectal cancer (CRC) commonly arises in individuals with premalignant colon lesions known as polyps, with both conditions being influenced by gut microbiota. Host-related factors and inherent characteristics of polyps and tumors may contribute to microbiome variability, potentially acting as confounding factors in the discovery of taxonomic biomarkers for both conditions. In this study we employed shotgun metagenomics to analyze the taxonomic diversity of bacteria present in fecal samples of 90 clinical subjects (comprising 30 CRC patients, 30 with polyps and 30 controls). Our findings revealed a decrease in taxonomic richness among individuals with polyps and CRC, with significant dissimilarities observed among the study groups. We identified significant alterations in the abundance of specific taxa associated with polyps (Streptococcaceae, <italic>Lachnoclostridium</italic>, and <italic>Ralstonia</italic>) and CRC (Lactobacillales, Clostridiaceae, <italic>Desulfovibrio</italic>, SFB, <italic>Ruminococcus</italic>, and <italic>Faecalibacterium</italic>). Clostridiaceae exhibited significantly lower abundance in the early stages of CRC. Additionally, our study revealed a positive co-occurrence among underrepresented genera in CRC, while demonstrating a negative co-occurrence between <italic>Faecalibacterium</italic> and <italic>Desulfovibrio</italic>, suggesting potential antagonistic relationships. Moreover, we observed variations in taxonomic richness and/or abundance within the polyp and CRC bacteriome linked to polyp size, tumor stage, dyslipidemia, diabetes with metformin use, sex, age, and family history of CRC. These findings provide potential new biomarkers to enhance early CRC diagnosis while also demonstrating how intrinsic host factors contribute to establishing a heterogeneous microbiome in patients with CRC and polyps.</p>