Some surprising facts about obesity research

Photo by Brooks Canaday

Photo by Brooks Canaday

This morning Northeastern’s government relations team and the Bouvé College of Health Sciences hosted a talk by Griffin Rodgers, the director of the NIH Institute for Diabetes and Digestive and Kidney Diseases. I wrote a story about the event this afternoon, which will appear on the News@Northeastern tomorrow morning. But in the mean time I wanted to tell you about a few amazing tidbits of research that he noted during the talk.

First off, the human microbiome. Rodgers called this the collection of “bacteria and other species that live on us and within us.” This ecosystem of micro-organisms that live inside our guts seem to be extremely important in mediating obesity, he said. In NIDDK-supported research led by Jefferey Gordon at Washington University, bacteria from obese mice were transplanted into the guts of lean mice, and without changing anything else, including diet and exercise, the latter group became obese themselves. The researchers did the same thing with bacteria from the guts of obese humans, and lo and behold the lean mice still beefed up. What’s more, the reverse happened when they switched the process around: Gut bacteria from lean mice caused obese mice to slim down without any changes to their diet or exercise regimes.

Next up: Sleep. We all know the importance of eating fewer calories and getting more exercise when it comes to losing weight. But perhaps lesser known is the fact that a good night’s sleep is necessary for those other things to have an affect. Research from Mitch Lazar’s lab at the University of Pennsylvania exposed the significance of the circadian clock in the production of body fat. Every cell in the body has a “biological clock” that tells it when certain processes should be active and when it should settle down and take a break. Messing with those clocks in the lab, either by perturbing an organism’s sleep schedule or by knocking out the clock genes altogether yields increased fat storage in places like the liver, for example. Rodgers pointed to the good ole Freshman 15, noting that perhaps students gain weight in their first months of college not just because their eating habits change, but also because their sleep schedules go completely haywire.

This idea of knocking out genes leads me to another interesting factoid that Rodgers brought up during the talk. Numerous genes have been linked to obesity and to both type 1 and type 2 diabetes. Perhaps not so surprisingly, there is a ton of overlap between them. Genes associated with diabetes are often also associated with obesity. As a result, nearly 50 percent of gene knockout studies, end up causing obesity. A researcher may try to knock out a gene they think is involved in cancer and suddenly find that their mice become overweight. This exact scenario happened in the lab of one of the audience members, biology professor Michail Sitkovsky.

The obesity and type 2 diabetes rates have been steadily increasing for the last fifty years. Two thirds of American adults and one third of children are obese or overweight while nearly 79 million people are at risk for diabetes. Obesity costs the nation between $150 and $200 billion a year and diabetes another $174 billion. Clearly something…or some things….need to be done to change the trend. The hope is that with funding from NIDDK, research like that mentioned above will be a part of the solution.