In the future you may be enlisting the microbes that live in your gut to help you lose weight. The bacteria that help us digest our food used to work in relative anonymity; in fact they were largely overlooked. No more. We now know they play a role in a wide variety of body rhythms and functions.

Probiotics help with digestive regularity. They also may help keep us slim — or not — according to new evidence from King’s College London and Cornell University.

Increasing the amount of a certain microbe found in the gut may help prevent or reduce obesity.

The link between the microbes in our gastrointestinal (GI) tract and conditions like diabetes has been known for some time. Results from this new study point directly to a certain microbe that can protect against weight gain.

Our genetic makeup predisposes us to harbor certain microbes over others, the team discovered. For that reason twins are more likely to have similar microbe compositions in their GI tracts compared to unrelated individuals.

People with a group of bacteria called Christensenellaceae tended to have a low body weight, the team found. And when the researchers introduced this bacterial species into mice, the mice had less weight gain, leading the researchers to believe that increasing the amount of this microbe may help prevent or reduce obesity.

“Our findings show that specific groups of microbes living in our gut could be protective against obesity — and that their abundance is influenced by our genes. The human Microbiome represents an exciting new target for dietary changes and treatments aimed at combating obesity,” Tim Spector, one of the researchers and department head of Twin Research and Genetic Epidemoiology at King’s College London, said in a statement.

The work has been become a basis for a large-scale “British Gut Project,” in which interested individuals can have the microbes in their GI tracts tested using a simple kit sent by mail.

The project is designed to provide each participant with information on his or her microbiota. And with data collected from many people, scientists expect they will learn more about the interaction between specific microbes and overall health.

The results could also help in the search for new ways to predict disease and improve prevention, Ruth Ley, professor at Cornell University and also one of the researchers involved in the study, said.

With any luck, the work will pave the path to personalized probiotic regimens that can be engineered to reduce the risk of obesity and associated conditions, all based on a person’s genetic makeup.

The study is published in Cell.