A Leeds University scientist, Simon Carding, has genetically altered or designed bacteria in order to treat inflammatory bowel disease or IBD.
The bacterium ; Bacterium ovatus, one of the 'good' bacteria in the human gut, was engineered to produce human growth factors called cytokines. These were used to repair the epithelial calls in the gut damaged by the disease, hence reducing the inflammation.
While viruses and bacteria have always been used for delivering drugs the problem was being able to control the production.
Says Carding "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.
"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."
Carding claims to have solved this by linking the human gene for producing cytokines with one of the bacteria's gene for breaking down a kind of sugar called xylan.
Xylan is a sugar that is mainly found in tree bark, and naturally present in food in only low concentrations and not part of most people's diets.
The trick is to add xylan to the diet of the patient, in the form of spoons of sugar.
On encountering the added source of xylan, the modified bacteria produce cytokines, which heal the gut.
A patient can control the amount of cytokines being produced by controlling how much xylan they eat; when the xylan runs out cytokine production stops.
Carding believes this discovery could even lead to further applications in medical science, like treatment of colorectal cancer.
He says," Treatment of diseases elsewhere in the body might also be possible as most things present in the gut can get taken into the blood stream.
"We are currently looking at bacteria that can release naturally occurring drug factors that shut down the blood supply to tumors, restricting their growth and preventing them spreading.
"We envisage the use of the bacteria as an adjuvant cancer therapy although we could try to combine it with another strain that would activate cytotoxic T-cells, allowing us to kill the cancerous cells as well."