Gut microbiome in tumorigenesis and therapy of colorectal cancer

Colorectal cancer (CRC) is the malignant tumor with the highest incidence in the digestive system, and the gut microbiome plays a crucial role in CRC tumorigenesis and therapy. The gastrointestinal tract is the organ harboring most of the microbiota in humans. Changes in the gut microbiome in CRC patients suggest possible host-microbe interactions, thereby hinting the potential tumorigenesis, which provides new perspective for preventing, diagnosing, or treating CRC. In this review, we discuss the effects of gut microbiome dysbiosis on CRC, and reveal the mechanisms by which gut microbiome dysbiosis leads to CRC. Gut microbiome modulation with the aim to reverse the established gut microbial dysbiosis is a novel strategy for the prevention and treatment of CRC. In addition, this review summarizes that probiotic antagonize CRC tumorigenesis by protecting intestinal barrier function, inhibiting cancer cell proliferation, resisting oxidative stress, and enhancing host immunity. Finally, we highlight clinical applications of the gut microbiome, such as gut microbiome analysis-based biomarker screening and prediction, and microbe modulation-based CRC prevention, treatment enhancement, and treatment side effect reduction. This review provides the reference for the clinical application of gut microbiome in the prevention and treatment of CRC.

Automated summary

Colorectal cancer (CRC) is the most common malignant tumor in the digestive system, and the gut microbiome plays a crucial role in its development and treatment. This review discusses the effects of gut microbiome dysbiosis on CRC and explores the mechanisms behind it. The modulation of gut microbiome is a novel strategy for preventing and treating CRC. Probiotics can protect the intestinal barrier, inhibit cancer cell growth, resist oxidative stress, and enhance the host's immune system to antagonize CRC tumorigenesis. Clinical applications of the gut microbiome, such as biomarker screening and prediction, as well as microbe modulation for CRC prevention, treatment enhancement, and reduction of side effects, are also highlighted.