Gut bacteria shift quickly after changes in diet, study shows

December 11, 2013 by Brenda Goodman, Healthday Reporter
Gut bacteria shift quickly after changes in diet, study shows
Number and type of gut microbes shifted within a day of eating plant- or animal-based foods exclusively.

(HealthDay)—If you were to switch from vegetarianism to meat-eating, or vice-versa, chances are the composition of your gut bacteria would also undergo a big change, a new study suggests.

The research, published Dec. 11 in the journal Nature, showed that the number and kinds of bacteria—and even the way the bacteria behaved—changed within a day of switching from a normal to eating either animal- or plant-based foods exclusively.

"Not only were there changes in the abundance of different bacteria, but there were changes in the kinds of genes that they were expressing and their activity," said study author Lawrence David, an assistant professor at the Institute for Genome Sciences and Policy at Duke University.

Trillions of bacteria live in each person's gut. They're thought to play a role in digestion, immunity and possibly even body weight.

The study suggests that this and its genes—called the microbiome—are extraordinarily flexible and capable of responding swiftly to whatever is coming its way.

"The gut microbiome is potentially quite sensitive to what we eat," David said. "And it is sensitive on time scales shorter than had previously been thought."

David said, however, that it's hard to tease out exactly what that might mean for human health.

Another expert agreed.

"It's nice to have some solid evidence now that these types of significant changes in diet can impact the in a significant way," said Jeffrey Cirillo, a professor of microbial and molecular pathogenesis at the Texas A&M Health Science Center College of Medicine in Bryan, Texas. "That's very nice to see, and it's very rapid. It's surprising how quick the changes can occur."

Cirillo said it was also intriguing how fast the microbiome seemed to recover. The study found that were back to business as usual about a day after people stopped eating the experimental diet.

For the study, researchers recruited six men and four women between the ages of 21 and 33. For the first four days of the study, they ate their usual diets. For the next five days, they switched to eating either all plant-based or all animal-based foods. They then went back to their normal eating habits before switching to the other diet pattern.

The animal-based diet resulted in the biggest changes to gut bacteria. It spurred the growth of 22 species of bacteria, while only three bacterial species became more prominent in the plant-based diet.

The researchers don't fully understand what the shifts mean, but, they said, some made sense. For example, several types of bacteria that became more prevalent with the animal-based diet are good at resisting bile acids. The liver makes bile to help break down fat.

Another type of bacteria, which became more common in the plant-based diet, is thought to be sensitive to fiber intake.

The researchers speculated that the bacterial shifts might explain why fatty diets have been linked to diseases like Crohn's and ulcerative colitis. More studies are needed, however, before they can say for sure.

Explore further: Your gut bacteria may predict your obesity risk

More information: Paper: dx.doi.org/10.1038/nature12820

Related Stories

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.

Gut microbes may be a risk factor for colorectal cancer

December 6, 2013
In one of the largest epidemiological studies of human gut bacteria and colorectal cancer ever conducted, a team of researchers at NYU Langone Medical Center has found a clear association between gut bacteria and colorectal ...

Genetic makeup and diet interact with the microbiome to impact health

September 25, 2013
A Mayo Clinic researcher, along with his collaborators, has shown that an individual's genomic makeup and diet interact to determine which microbes exist and how they act in the host intestine. The study was modeled in germ-free ...

Gut microbe makeup affected by diet: study

September 2, 2011
(PhysOrg.com) -- A new study in the US has shown that the type of "good" bacteria that predominate in human stools varies with the diet.

How bacteria with a sweet tooth may keep us healthy

October 25, 2013
Some gut bacterial strains are specifically adapted to use sugars in our gut lining to aid colonisation, potentially giving them a major influence over our gut health.

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

Post-stroke patients reach terra firma with new exosuit technology

July 26, 2017
Upright walking on two legs is a defining trait in humans, enabling them to move very efficiently throughout their environment. This can all change in the blink of an eye when a stroke occurs. In about 80% of patients post-stroke, ...

Molecular hitchhiker on human protein signals tumors to self-destruct

July 24, 2017
Powerful molecules can hitch rides on a plentiful human protein and signal tumors to self-destruct, a team of Vanderbilt University engineers found.

Researchers develop new method to generate human antibodies

July 24, 2017
An international team of scientists has developed a method to rapidly produce specific human antibodies in the laboratory. The technique, which will be described in a paper to be published July 24 in The Journal of Experimental ...

New vaccine production could improve flu shot accuracy

July 24, 2017
A new way of producing the seasonal flu vaccine could speed up the process and provide better protection against infection.

A sodium surprise: Engineers find unexpected result during cardiac research

July 20, 2017
Irregular heartbeat—or arrhythmia—can have sudden and often fatal consequences. A biomedical engineering team at Washington University in St. Louis examining molecular behavior in cardiac tissue recently made a surprising ...

Want to win at sports? Take a cue from these mighty mice

July 20, 2017
As student athletes hit training fields this summer to gain the competitive edge, a new study shows how the experiences of a tiny mouse can put them on the path to winning.

0 comments

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.