Abstract
Non-digestible carbohydrate (NDC) is a fiber that can be fermented into short chain fatty acids (SCFAs) in gut, represented by resistant starch (RS) and inulin. Colorectal cancer (CRC) is one of the most common malignant cancer. Pre-clinical studies have reported that NDC can produce SCFAs to protect the gut epithelium, which is associated with prevention of CRC, but this role in clinical trails is controversial. In this review, we discusses whether RS and inulin should be offered to cancer/precancerous patients or healthy subjects to decrease their risk of CRC. A multiple database search was conducted for studies published on RS/inulin supplementation as a chemopreventive method from 1989 to 2019. The meta-analysis showed the total SCFAs and butyrate concentrations (P = 0.84; P = 0.79), and excretions (P = 0.55; P = 0.63) in feces did not increase significantly after RS/inulin supplementation. Only two studies reported that RS/inulin inhibit the proliferation of large bowel epithelial, whereas 15 studies showed that it does not decrease the risk of neoplasia. RS/inulin restored the promotion of tumor risk factors in two studies and did not in four studies. Notably, the other four studies showed that RS increases pro-tumorigenesis mechanisms. The clinical evidences consistently show that RS/inulin is ineffective for preventing colorectal neoplasia.
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The authors would like to thank BioMed Proofreading LLC for English expression polishing.
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The authors report no conflict of interest.
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Mingyue Rao
Author Mingyue Rao was responsible for study design, literature search and review, draft writing and final manuscript confirmation. The author Chenlin Gao collected and analyzed data, modified the results section of the draft, and confirmed the final manuscript. The authors Jing Hou and Junling Gu were responsible for complementing the interpretation of the results, revising the introduction and discussion sections of the draft and the final confirmation. Betty Yuen Kwan Law and Yong Xu adjusted the scope of the topic, revised the full text and embellished it in English and approved the final draft.