Gut bugs aid anti-cancer, suggests research

Bacteria in the lower gut enable the release of the cancer-fighting agent sulphoraphane contained in the vegetable, scientists believe.

"This discovery raises the possibility that we will be able to enhance the activity of these bacteria in the colon, increasing broccoli's cancer-preventive power," said American nutrition expert Professor Elizabeth Jeffery, from the University of Illinois.

She said many people destroy the plant enzyme that produces sulphoraphane by overcooking broccoli.

"Now we know the microbiota in our digestive tract can salvage some of this important cancer-preventive agent even if that happens," said Prof Jeffery.

Her team made the discovery after carrying out experiments on rats.

The researchers showed sulphoraphane becomes available for absorption into the body in the lower intestine, which houses the bacteria that aid digestion and metabolism.

Sulphoraphane, which has anti-inflammatory properties, is said to be a potent anti-cancer agent.

"The amount that you get in three to five servings a week - that's less than one daily serving of broccoli - is enough to have an anti-cancer effect," said Prof Jeffery.

She said it may be possible to boost numbers of the helpful bacteria by feeding them dietary fibre.

Another strategy might be to combine broccoli with a yoghurt containing the bugs.

"One of the things we don't think about very much is the enormous amount of benefit we experience when a healthy community of bacteria colonises the lower intestine," she added.

The latest research into the healthy properties of broccoli appears in the journal Food & Function.