Bacteroides Fragilis Supernatant Plays Anti-Viability Roles Accompanied by Apoptosis and Cell Cycle Arrest via P62/Caspase8/ Bax/Fas Pathway in Colorectal Adenocarcinoma Cell Line

From two classes of bacteroides fragilis, enterotoxigenic b. fragilis (etbf) is associated with colorectal cancer (crc), yet several non-toxigenic b. fragilis (ntbf) confers powerful health benefits to the host and may be potential probiotic. in this study, the ht-29 cell line was treated with the supernatant of ntbf strain atcc-23745. then, the expression level of mtor /p62/caspase8/bax proposed signaling pathway and cell viability, cell apoptosis, and cell cycle progression were determined using real-time pcr and flow cytometry, respectively. we found that the b. fragilis supernatant inhibited cell proliferation and increased cell apoptosis in a dose- and time-dependent manner. further, the arrest of the ht-29 cells at the g1 and sub-g1 phases also signified apoptotic cell death after 24 and 72h. the gene expression study revealed that the supernatant significantly up-regulated the caspase8/bax/fas-mediated apoptosis signaling while suppressing the anti-apoptotic mtor and p62 expression. our findings suggest that the ntbf atcc-23745 strain may be a potential probiotic and can be used in crc treatment.