Feces and Fat: Possible Link Between Fecal Bacteria and Obesity

Feces and Fat: Possible Link Between Fecal Bacteria and Obesity

By Kurtis Bright

How Bacteria In Feces Has Been Linked to Inherited Obesity

You’re a big, fat stinkin’ mess. So says a group of British researchers, anyway.

Okay, that’s not exactly true. But what they are saying is that the content of our feces may well play a role in how much fat we store in our bodies--and possibly even tell us who has an inherited propensity for obesity.

An exciting new study out of the U.K. seems to demonstrate that the makeup of the bacteria found in the feces of individual people may be linked to the levels of dangerous types of fat we have in our bodies. Researchers think could lead to breakthroughs on how and why obesity is passed along in families as well.

Carried out by researchers at King’s College in London, the study analyzed stool samples from more than 3,600 sets of twins. What they found was that there is ample evidence that at least some of the composition of this bacteria is heritable, thus offering the beginnings of an explanation for why obesity is an inherited trait.

They compared data culled from the samples provided by the study participants to six different measures of obesity, including body mass index and the composition of a person’s body fat, they distinct types we carry. Thus the researchers were able to find a correlation with visceral fat, an especially dangerous fat type that is stored in the abdomen, giving people not only the “spare tire” look, but also pressing in on surrounding organs like the liver, pancreas and intestines. Having excess visceral fat has also been connected to higher risk for cardiovascular disease and diabetes.

Although the study showed a clear link between this particular type of fecal bacteria and fat, lead author Dr. Michelle Beaumont of The Department of Twin Research and Genetic Epidemiology at King's College London was quick to point out that it is not yet possible to explain why there might be such a connection.

“As this was an observational study we cannot say precisely how communities of bacteria in the gut might influence the storage of fat in the body, or whether a different mechanism is involved in weight gain,” she said.

Researchers theorize that perhaps a lack of variety in fecal bacteria could lead to higher levels of the types of gut microbes that specialize in turning carbohydrates into fat.

There is certainly a growing body of evidence that gut bacteria has a much greater influence over many biofunctions: not only obesity, but also our mental health and brain function too.

For some time we’ve known that the composition of at least half of human feces is bacteria that is shed from the gut. Indeed, Dr. Beaumont suggested that eating a wider variety of different types of foods--as our hunter-gatherer ancestors did, long before monocrops and industrial food production had limited our choices the way they are today--could lead to more diversity of microbes in our gut biome.

The research--published in the journal Genome Biology--should if nothing else create new avenues for future research that will help us better understand how gut bacteria, and thus obesity may be passed down in families.

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