Researchers at Cornell University analyzed gut bacteria from more than 1,000 fecal samples in the TwinsUK study, including 416 twin pairs, to see which microbial groups were shaped more by genetics than by diet or environment.
A bacterial family called Christensenellaceae was the most heritable microbe found, its levels more alike in identical twins than in non-identical twins. It was also consistently enriched in people with a lower body mass index, and formed a network with other heritable, weight-associated microbes.
To test whether the bacterium caused leanness rather than just tracking with it, the team added Christensenella minuta, a cultured member of the family, to an obese-associated microbiome and transplanted it into germ-free mice. The mice gained less weight than controls. The result does not mean the bacterium alone determines a person's weight, since diet, other microbes and genetics all still interact with it.
Read the original study
Goodrich et al., Cell, 2014 · doi.org/10.1016/j.cell.2014.09.053
A gene's influence on weight ran through the gut.
Source
- Goodrich, J. K., Waters, J. L., Poole, A. C., Sutter, J. L., Koren, O., Blekhman, R., Beaumont, M., Van Treuren, W., Knight, R., Bell, J. T., Spector, T. D., Clark, A. G., & Ley, R. E. (2014). Human genetics shape the gut microbiome. Cell, 159(4), 789–99. https://doi.org/10.1016/j.cell.2014.09.053