The medic within

A biologist has created a way to make bacteria in our own bodies produce medicine to treat Inflammatory Bowel Disease (IBD).

Bacteria like salmonella can cause illness, but modified gut bacteria could deliver medicine whenever the patient requires. (Pic credit:Rocky Mountain Laboratories, NIAID, NIH)

Bacteria and viruses have been used before to deliver drugs in this way, but Professor Carding of Leeds’ Faculty of Biological Sciences has solved the major problem with this kind of treatment - he uses a sugar to ‘switch’ the bacteria on and off. By eating the sugar, a patient will set the medicine to work and can end the treatment simply by stopping consumption of the sugar.

“Current bacteria and virus delivery systems produce their drugs non-stop, but for many treatments there is a narrow concentration range at which drugs are beneficial,” said Professor Carding. “Outside of this, the treatment can be counterproductive and make the condition worse. It’s vitally important to be able to control when and how much of the drug is administered and we believe our discovery will provide that control.”

Professor Carding has modified one of the trillions of bacteria in the human gut so that it will produce human growth factors which help repair the layer of cells lining the colon, so reducing inflammation caused by IBD. He has also adapted the bacteria so it only activates in the presence of a plant sugar called xylan that is found in tree bark. Xylan is naturally present in food in low concentrations, so by taking it in higher quantities, a patient will be able to produce their own medicine as and when they need it.

The technique has been shown to work in vitro, but the researchers will be testing the treatment over the next twelve months in preparation for clinical trials.