How gut bacteria, broccoli can help keep bowel cancer away

Singapore: Researchers have developed a cocktail of bacteria and cruciferous vegetables that can potentially turn into a targeting system that seeks out and kills colorectal cancer cells.

Colorectal cancer is the third most common cancer worldwide, after lung and prostate cancer.

Although the 5-year survival rates for earlier stages of this cancer are relatively good, at later stages survival goes down and the risk of cancer recurrence goes up considerably.

Thus researchers, from the National University of Singapore, developed a mixture of engineered probiotics with a broccoli extract or water containing the dietary substance.

This mixture killed more than 95 per cent of colorectal cancer cells in a dish.

Further, the probiotics-veggie combination also reduced tumour numbers by 75 per cent in mice with colorectal cancer.

However, the mixture had no effect on cells from other types of cancer such as breast and stomach cancer.

These probiotics could be used as prevention and to clean up the cancer cells remaining after surgical removal of tumours, the researchers said.

"One day, colorectal cancer patients may be able to take the probiotics as a dietary supplement along with broccoli to prevent colorectal cancer or to reduce recurrence after cancer surgery," said lead author Chun-Loong Ho from the varsity.

For the study, published in the journal Nature Biomedical Engineering, the team developed a cancer-targeting system by engineering a form of E.coli Nissle -- a harmless type of bacteria found in the gut.

Then using genetic techniques, they engineered the bacteria into a probiotic that attached to the surface of colorectal cancer cells and secreted an enzyme to convert a substance found in broccoli, into a potent anti-cancer agent.

The idea was for the cancer cells in the vicinity to take up this anticancer agent and be killed.