Association of with colorectal cancer: A systematic review of and evidences.

Background: Recently, there have been several findings that showed intestinal colonisation of () as a risk factor to the worsening of colorectal cancer (CRC). However, studies have shown controversial results in the pathogenicity of .

Aim: To review systematically the evidence available on the association between CRC and and the prevalence of in CRC patients and to investigate cytopathic and immunological effects of in and studies.

Methods: PRISMA guidelines were utilised in conducting this systematic review. Original articles published before February 2, 2020 were included. PubMed, Science Direct, Scopus and Google scholar databases were searched. Manual searching was carried out to find articles missed during the online search.

Results: Out of 12 studies selected for this systematic review, seven studies confirmed the prevalence of and found it to be between 2%-28% in CRC patients, whereby subtype 1 and subtype 3 were predominantly seen. A total of four studies employing human colorectal carcinoma cell line study models showed significant cytopathic and immunological effects of . In addition, one experimental animal model study showed that there was a significant effect of infection with on exacerbation of colorectal carcinogenesis.

Conclusion: is a commonly identified microorganism in CRC patients. These studies have provided supportive data that could exacerbate existing CRC alteration in host immune response and increased oxidative damage. Future studies of CRC and should attempt to determine the various stages of CRC that are most likely to be associated with and its relationship with other intestinal bacteria.