Variations in Human Gut Microbiome Linked to Obesity

Mitchell L. Sogin, Ph.D.
Marine Biological Laboratory, Woods Hole, Massachusetts
NIEHS Grant P50ES012742

A study partially funded by NIEHS and published in the journal Nature has found that the gut microbial population in humans is unique to each individual and that there are substantial differences between obese and lean people. Researchers at the NIEHS funded center at the Marine Biological Laboratory in Woods Hole, MA participated in the study.

The researchers analyzed the gut microbiomes of lean and obese, fraternal and identical female twins and their mothers. They found that the collection of bacteria is similar in related individuals, but not identical. The study participants are part of a long-standing study of Missouri-born twins designed to decipher the influence of the environment versus genetics on many aspects of human health.

Peter Turnbaugh, lead author of the study and a graduate student at Washington University, sequenced the microbial DNA of a subset of obese and lean twin pairs. He found that the obese individuals had an increase in nearly 300 bacterial genes primarily responsible for extracting calories from food and processing nutrients. These findings support earlier work in mice that established a connection between obesity and energy harvested from the diet by gut bacteria.

Family members were more likely to harbor similar communities of bacteria; however the degree of similarity was the same for identical and fraternal twins regardless of whether they lived together or in different regions of the U.S. This finding suggests that early environmental exposures play a key role in determining which bacteria colonize our intestinal tracts.

Citation: Turnbaugh PJ, Hamady M, Yatsunenko T, Cantarel BL, Duncan A, Ley RE, Sogin ML,Jones WJ, Roe BA, Affourtit JP, Egholm M, Henrissat B, Heath AC, Knight R, Gordon JI. A core gut microbiome in obese and lean twins. Nature. 2009 Jan 22;457(7228):480-4.