A team of researchers led by Professor Mark Huycke has discovered connection between a common gut bacterium and colon cancer. Researchers believe that this bacterium plays a key role in development of colon cancer. Enterococcus faecalis is harmless in the vast majority of people but research has shown that it can produce harmful chemicals.  

US scientists found out that this bacterium produces a molecule which activates signalling pathways that are associated with cancer cells. The research has shown that unlike most gut bacteria, E. faecalis is able to use fermentation to survive. It is a by-product of the process – an oxygen molecule called superoxide – which can damage DNA and may play a role in the formation of colon tumours. 

The authors said that the research showed that superoxide from E. Faecilis led to strong signalling in immune cells called macrophages. It also altered the way some cells in the gut grew and divided and even increased the productivity of genes that are associated with cancer.

Researchers added that in total, the expression of 42 genes linked to vital processes in human cells was altered by the presence of E. faecalis in this state.  

Dr Barry Campbell, a gut microbiology researcher from the University of Liverpool, agreed that E.faecalis was a candidate for cancerous changes. He added that other bowel bacteria could also be behind the cell changes which eventually lead to tumours.  

Researchers said that the present research puts into perspective the complexity of the effects normal gut bacteria can have on the health of the individual