Researchers found they could alter the bacteria, which is found naturally in the human gut and in probiotic yogurts, to make it produce a type of molecule that has been shown to reduce levels of fat tissue in the body.
The scientists, from the Irish Agriculture and Food Development Authority and Cork University, hope they will be able to produce new types of probiotic yogurts and drinks that can help to cut obesity.
Dr Catherine Stanton, who led the research at the Irish Agriculture and Food Development Authority, said: "Fat is not an inert layer around our bodies, it is active and proinflammatory. It is a risk factor for many diseases including cancers.
"This work shows that there is potential to influence fat tissue through diet-microbe-host interactions in the gut. It opens up new possibilities for the use of probiotics for improving human health."