From one end to the other

BBC News - Mouth bacteria may trigger bowel cancer

Researchers say they have uncovered how bacteria may set off a chain reaction leading to bowel cancer. 

Fusobacteria, commonly found in the mouth, cause overactive immune responses and turn on cancer growth genes, two US studies reveal.

The microbes had been linked with colorectal cancer before but it was not known whether they were directly involved in tumour growth.

The early findings are published in the journal Cell Host & Microbe.

In addition to potential new treatments, the discovery could lead to better early diagnosis and prevention, experts hope.

The first study, carried out by Harvard Medical School researchers, showed that fusobacteria were present in high numbers in adenomas - a benign bowel growth that can become cancerous over time.

The same researchers also did tests in mice showing that the bacteria speeded up the formation of colorectal tumours by attracting special immune cells that invade and set off an inflammatory response which can lead to cancer.