Bacteria in the mouth may be linked to bowel cancer, according to new research.

The research, which is in its early stages, indicates that tests could eventually be developed to identify people at higher risk of colo-rectal cancer and could also help the development of new drug treatments.

Bugs called fusobacteria, that are often found in the mouth, can trigger genes that can promote the growth of cancer, US researchers say.

One US study found that there was a high level of fusobacteria in benign bowel tumours that can turn cancerous.

This research, carried out at Harvard Medical School, also performed tests in mice showing that this type of bacteria speeded up the formation of colo-rectal tumours.

The other study, carried out at Case Western Reserve University, showed that fusobacteria contain a molecule which enabled the bug to infiltrate bowel cancer cells. This molecule switches on cancer growth genes.

The research is published in the journal Cell Host & Microbe.