Study shows gut bacteria associated with obesity varies by geographic latitude

February 12, 2014 by Bob Yirka report
Credit: © Suzuki et al

(Medical Xpress)—A pair of researches has found that the proportions of two types of gut bacteria known to have an impact on weight retention differ by geographic latitude. In their paper, published in the journal Biology Letters, Taichi Suzuki and Michael Worobey of the Universities of California and Arizona respectively describe how they studied gut data of people from around the world and found that the amounts of two types of bacteria associated with weight gain or loss was different depending on where people lived.

Scientists know that animals that live in colder climates tend to be bigger than those in the warmer climates—many species that live in cold climates also have a lot of fat to help them keep warm. It's also been found that the in animals such as mice differ based on if they live in a warm or cold climate. In this new study, the researchers wanted to know if gut bacteria might be different for people living in warm versus as well. To find out, they accessed several medical databases that held information regarding gut bacteria from people who live in various places all over the planet—in all they studied the gut bacteria of 1,020 people from 23 different parts of the world, ranging from hot to cold. In so doing, they discovered that those who live in latitudes farther from the equator (colder places) had more of a bacteria family known as Firmicutes in their guts than did those that lived in warmer climates and less of a family known as Bacteroidetes. This is important because Firmicutes have been associated with causing an increase in body fat retention, while Bacteroidetes have been shown to have the opposite effect.

The results of their study aren't enough to suggest that living in a warm or cold climate causes changes to gut biota—it's possible after all that people eat differently because of where they live—or an increase or decrease in likelihood of retaining body fat, but it does show that there are differences and that appears to be enough to warrant further study—if only to find out if living in a colder climate means having a harder time keeping the weight off.

Explore further: Team develops method of identifying impact of gut microbes

More information: Geographical variation of human gut microbial composition, Biol. Lett. February 2014 vol. 10 no. 2 20131037, Published 12 February 2014 doi: 10.1098/rsbl.2013.1037

Although we know there is considerable variation in gut microbial composition within host species, little is known about how this variation is shaped and why such variation exists. In humans, obesity is associated with the relative abundance of two dominant bacterial phyla: an increase in the proportion of Firmicutes and a decrease in the proportion of Bacteroidetes. As there is evidence that humans have adapted to colder climates by increasing their body mass (e.g. Bergmann's rule), we tested whether Firmicutes increase and Bacteroidetes decrease with latitude, using 1020 healthy individuals drawn from 23 populations and six published studies. We found a positive correlation between Firmicutes and latitude and a negative correlation between Bacteroidetes and latitude. The overall pattern appears robust to sex, age and bacterial detection methods. Comparisons between African Americans and native Africans and between European Americans and native Europeans suggest no evidence of host genotype explaining the observed patterns. The variation of gut microbial composition described here is consistent with the pattern expected by Bergmann's rule. This surprising link between large-scale geography and human gut microbial composition merits further investigation.

Press release

Related Stories

Team develops method of identifying impact of gut microbes

January 23, 2014
(Medical Xpress)—A team of researchers at Washington School of Medicine in St. Lois has developed a method for identifying the impact that individual strains of microbes in the human gut have on the person housing them. ...

Why do the different people's bodies react differently to a high-fat diet?

April 26, 2012
Gut flora, otherwise knows as gut microbiota, are the bacteria that live in our digestive tract. There are roughly one thousand different species of bacteria, that are nourished partly by what we eat. Each person has their ...

Your gut bacteria may predict your obesity risk

August 28, 2013
(HealthDay)—Bacteria in people's digestive systems—gut germs—seem to affect whether they become overweight or obese, and new research sheds more light on why that might be.

Eczema in infants linked to gut bacteria

January 22, 2013
Children with eczema have a more diverse set of bacteria in their guts than non affected children, finds a new study in BioMed Central's open access journal BMC Microbiology. The types of bacteria present were also more typical ...

Scientists investigate the fiber of our being

January 19, 2014
We are all aware of the health benefits of "dietary fibre". But what is dietary fiber and how do we metabolise it?

Bacteria tails implicated in gut inflammation

December 11, 2013
In healthy individuals, the only thing that separates the lining of the human gut from the some 100 trillion bacterial cells in the gastrointestinal tract is a layer of mucous.

Recommended for you

Hibernating ground squirrels provide clues to new stroke treatments

November 17, 2017
In the fight against brain damage caused by stroke, researchers have turned to an unlikely source of inspiration: hibernating ground squirrels.

Age and gut bacteria contribute to multiple sclerosis disease progression

November 17, 2017
Researchers at Rutgers Robert Wood Johnson Medical School published a study suggesting that gut bacteria at young age can contribute to multiple sclerosis (MS) disease onset and progression.

Molecular guardian defends cells, organs against excess cholesterol

November 16, 2017
A team of researchers at the Harvard T. H. Chan School of Public Health has illuminated a critical player in cholesterol metabolism that acts as a molecular guardian in cells to help maintain cholesterol levels within a safe, ...

Prototype ear plug sensor could improve monitoring of vital signs

November 16, 2017
Scientists have developed a sensor that fits in the ear, with the aim of monitoring the heart, brain and lungs functions for health and fitness.

Ancient enzyme could boost power of liquid biopsies to detect and profile cancers

November 16, 2017
Scientists are developing a set of medical tests called liquid biopsies that can rapidly detect the presence of cancers, infectious diseases and other conditions from only a small blood sample. Researchers at The University ...

FDA to crack down on risky stem cell offerings

November 16, 2017
U.S. health authorities announced plans Thursday to crack down on doctors pushing stem cell procedures that pose the gravest risks to patients amid an effort to police a burgeoning medical field that previously has received ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.