New evidence that a common gut bacterium is involved in bowel cancer has been discovered by researchers from the Department of Physiology and Medical Physics in RCSI.

The research is published in this month’s edition of the European Journal of Clinical Microbiology & Infectious Diseases.

The HRB funded research, led by Dr David Hughes at the Department of Physiology and Medical Physics, RCSI found a significantly increased presence of a common microbe Fusobacterium nucleatum (Fn) in tissue and stool samples of patients with colorectal cancers and colorectal benign tumours. 

Additionally Fn infection levels were related with benign tumour progression from early to advanced stages and the transition from a benign tumour to cancer.

Commenting on the research, Dr David Hughes, said: “Our research found that cancer patients with low bacterial levels had significantly longer survival times than patients with moderate and high levels of the bacterium. Also, for patients with a benign tumour, we found that the presence of Fn may be a risk factor for disease progression from tumour to cancer. This is a significant finding because it highlights the potential of Fn detection as a possible indicator of colorectal cancers.”

The research highlights that screening for Fn levels may be used as a new bowel cancer detection method or to further inform existing screening strategies. Efforts to combat Fn infection could be considered for colorectal cancers patients with high levels of the bacterium to improve the survival prospects for these patients.

For patients with benign tumours, Fn levels may be used to classify the tumours that may have a higher risk of disease progression to colorectal cancers with implications for increasing follow-up and at the possible use of anti-microbial treatments.

Dr Hughes added: “Potentially, any impact of Fn infection on benign tumour development and progression to more serious stages will be considerable, because 95% of all bowel cancers arise from benign tumours, but only a small number of them become cancerous. Currently, there are no reliable predictive markers of whether a benign tumour will advance to cancer.”