Effects of fecal microbiota transplantation combined with selenium on intestinal microbiota in mice with colorectal cancer.

Colorectal cancer (CRC) is the third most common cancer in the world. With the development of high-throughput gene sequencing technology, homeostasis imbalance of the intestinal microbiota has been proven to play a key role in the pathogenesis of CRC. Furthermore, fecal bacteria transplantation (FMT) has been shown to alter the intestinal microecology, and is potentially an effective treatment for CRC. Sodium selenite plays an important role in anticancer adjuvant therapy due to its high pro-oxidation characteristics. In this study, a murine CRC tumor model was induced by AOM/DSS, and CRC mice were treated by FMT, sodium selenite, and FMT combined with sodium selenite. The results showed that FMT, sodium selenite, and FMT combined with sodium selenite inhibited the occurrence of CRC in mice, increased the abundance of beneficial intestinal bacteria, produced different microorganisms, and changed the metabolic pathways of the intestinal microbiota. In summary, FMT, sodium selenite, and FMT combined with sodium selenite can inhibit the occurrence of CRC by increasing the abundance of beneficial bacteria and regulating phenotypes and metabolic pathways. Notably, the effect of FMT combined with sodium selenite in reducing the number of tumors, protecting intestinal tissues, and restoring the diversity and richness of the intestinal microbiota is superior to that of FMT alone or sodium selenite alone. The results of this study provide new ideas for the application of FMT and selenium in the treatment of CRC.