Protective effect of the food-microorganism-SCFAs axis on colorectal cancer: from basic research to practical application

Background Recent studies have shown that the short-chain fatty acids (SCFAs) produced by the gut microbiota play a positive role in the development of colorectal cancer (CRC). Aims This study aims to elucidate the food-microorganism-SCFAs axis and to provide guidance for prevention and intervention in CRC. Methods The PubMed, Embase and Cochrane databases were searched from their inceptions to August 2018, and 75 articles and 25 conference abstracts were included and analysed after identification and screening. Results The concentrations of SCFAs in CRC patients and individuals with a high risk of CRC were higher than those in healthy individuals. The protective mechanism of SCFAs against CRC has been described in three aspects: epigenetics, immunology and molecular signalling pathways. Many food and plant extracts that were fermented by microorganisms produced SCFAs that play positive roles with preventive and therapeutic effects on CRC. The food-microorganism-SCFAs axis was constructed by summarizing the pertinent literature. Conclusions This study provides insight into the basic research and practical application of SCFAs by assessing the protective effect of SCFAs on CRC.