Bacterial Profiling of Colorectal Cancer Biopsies: A Culture-Based Study in Indian Patients

Emerging research has highlighted the significant role of microorganisms in the initiation and progression of colorectal cancer (CRC). However, further investigation is required to elucidate the precise mechanisms by which the microbial community or specific bacteria contribute to carcinogenesis. The present work deals with the isolation and identification of bacteria from 9 colorectal cancer biopsy samples and 9 adjacent biopsy samples. Different media, such as Brain Heart Infusion (BHI), Anaerobic Basal Agar (ABA), Trypticase Soy Agar (TSA), and culture conditions have been manipulated to maximize the isolation of bacteria residing in biopsy samples. A total of 75 bacteria were isolated from the tumor and adjacent site. Enterococcus, Escherichia, Klebsiella, Shigella, Citrobacter, Morganella and Veillonella have been found to be enriched in most of the cancerous biopsies, while biopsies collected from adjacent tissues had Escherichia, Shigella, Enterococcus, and Streptococcus bacteria. A culture-based approach to determining bacterial diversity has its own advantages, which allows the study of a single bacterium to understand the events leading to the development of intestinal carcinogenesis. This culture-based approach may provide novel insights into pathology and potentially lead to new therapeutic modalities targeting the specific bacteria implicated in the inflammation and carcinogenesis of colorectal cancer.