Bacteria found in certain bowel cancers can also be found inside a small number of tumours that have spread to another part of the body, says new research. The bacteria helped bowel cancer cells grow in mice. Researchers said this adds to the evidence of a relationship between growing bowel cancers and the types of microorganisms in the gut. The Dana-Farber Cancer Institute team analysed tumour samples from 101 patients who had bowel cancer that had spread. Samples were taken from where the tumour started in the gut and where it spread to in the liver. 43 patients had large amounts of a type of bacteria called Fusobacteria inside their bowel cancer cells. 20 patients also had the same bacteria inside bowel cancer cells that had spread to the liver.