Some surprising facts about obesity research

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.