(HealthDay News) — Genes influence a person’s body weight by determining the types of bacteria that live in the intestines, according to a study published in Cell.

“Up until now, variation in the abundances of gut microbes has been explained by diet, the environment, lifestyleand health,” senior study author Ruth Ley, PhD, of Cornell University in Ithaca, New York, said in a journal news release. 

“This is the first study to firmly establish that certain types of gut microbes are heritable — that their variation across a population is in part due to host genotype variation, not just environmental influences.”

Continue Reading

For the study, researchers looked at 416 pairs of twins and identified a family of intestinal bacteria that is more common in lean people (Christensenellaceae). The genes associated with this family of bacteria are highly heritable. 

The investigators also transplanted this family of bacteria from people to mice and found that the bacteria protected the mice against weight gain. The findings could lead to therapies where people at risk for obesity and related diseases due to their genetic makeup are given these weight-fighting bacteria.

“Our results showing that bacterial abundances run in families may be useful for disease risk prediction,” Ley said. She added that the microbiome is an “attractive target” for treatments. 

“By understanding the nature of our association with these health-associated bacteria, we could eventually exploit them to promote health,” she explained.


  1. Goodrich JK et al. Cell. 2014;doi:10.1016/j.cell.2014.09.053.