Obesity is a major public health issue in much of the developed world. It’s well known that a healthy diet and regular exercise are key to losing weight, but there is another factor that may be just as influential—our microbiome.

The microbiome, defined as the microbial communities that live in and on our bodies, has a huge impact on health. And though we know that microbial cells are prevalent, outnumbering human cells by about ten to one, much of what they do and how they interact with us remains a mystery.

In response to a call for proposals issued by the Mayo-Illinois Alliance in July 2013, researchers from the University of Illinois at Urbana-Champaign and the Mayo Clinic in Rochester, MN, have teamed up to find out if a person’s gut microbiome can predict how well that person will respond to a lifestyle intervention, in terms of weight and body fat loss.

The project brings together a diverse group of researchers with interest and expertise in obesity interventions and the microbiome. The Illinois team is led by Dr. Jeff Woods from the Department of Kinesiology and Community Health, and includes Drs. Hanna Holscher and Kelly Swanson from the Animal Sciences Department. The Mayo team is led by Dr. Vandana Nehra from the Department of Gastroenterology and Hepatology. Dr. Nehra is joined by Drs. Joe Murray and Lisa Boardman also from Gastroenterology and Hepatology, and Dr. Mike Jensen from Endocrinology.

Previous research has already implicated certain types of microbes in exacerbating obesity, as well as in keeping individuals lean, regardless of diet. This study will use a weight loss intervention program already in progress at the Mayo Clinic to examine the effect of the intervention on the microbiome, and therefore if alterations of the gut microbiome might be a contributing factor to the long-term efficacy of the program. The year-long program incorporates exercise (primarily walking) and a volumetric diet (i.e., a diet high in fiber and resistant starch) for weight loss.

Mayo-Illinois Alliance researchers anticipate that the results of this study could someday be used to design individualized weight-loss therapies, possibly involving the use of prebiotics or even fecal transplantation to alter the gut microbiome. Using the gut microbiome as a diagnostic tool for the screening and prevention of obesity or metabolic syndrome is another potential health outcome.