Claremore Daily Progress

Community News Network

December 11, 2013

Harvard study finds diet changes gut bacteria within a day

WASHINGTON — A change in diet quickly alters the types of bacteria living in the human gut, a finding that suggests this rapid adaptability to different foods can be used to control illnesses tied to stomach microbes, researchers said.

Switching to an animal-based diet increased the number of microorganisms that process protein, while a plant-based diet increased the number of bacteria that help process starch and cellulose, according to a study led by Harvard University researchers published Wednesday in the journal Nature. The change in the bacteria populations occurred within a day.

Trillions of microorganisms live in the human gut, helping to digest food, fight disease-causing germs and process nutrients. Research has suggested that diets high in fat and sugar may change the human gut's bugs, perhaps contributing to chronic illness, the study authors wrote. Previous work in mice suggested that the microbiome could change within a day, though until now, the effect hadn't been replicated in humans.

"It's exciting and gratifying to find out this holds up in people," said Lawrence David, who was one of the Harvard researchers and is now an assistant professor at Duke University's Molecular Genetics & Microbiology and Institute for Genome Sciences & Policy. "We're getting an increasing appreciation of how flexible and responsive the microbiome is, even on a very short time scale."

Humans are home to more than 10,000 species of microbes, mostly bacteria that live in healthy symbiosis, according to the Human Microbiome Project. The trillions of microorganisms that live in and on the body outnumber human cells by 10 to 1, according to research published in 2012 in Nature and the Public Library of Science journals.

Scientists are just beginning to explore the composition of these ecosystems, said David. Knowing how these organisms interact with their host can reveal more about illnesses such as inflammatory bowel disease and obesity.

The 11 people studied were allowed to eat as they normally did for four days, writing down what they ate and submitting fecal samples to the researchers. Then they consumed what was provided to them by researchers for four days, and were watched for six days afterward. That meant that each person essentially served as their own control group, David said.

The plant-based diet, which boosted fiber intake significantly and dropped fat and protein intakes, led to very few changes in the existing microbes. The animal-based diet had almost no fiber intake had a "really big shift," David said.

The animal-based diet caused changes in the population, including an increase in the anaerobic bacteria Bilophila wadsworthia, which is known to cause colitis in mice. The bacteria seem to thrive with the increased intake of fat, David said. Some bacteria also changed their gene expression with the diet, the study found.

"Perhaps in prehistoric groups, when there was a lot more volatility in terms of what you can forage or hunt for, this could have been very useful," David said. "It creates a way of buffering nutritional changes and may have enabled ancient humans to be a little more flexible with their diet."

Further research may focus on how food preparation affects the bacterial colonization, David said.

 

1
Text Only
Community News Network
  • Arizona's prolonged lethal injection is fourth in U.S. this year

    Arizona's execution of double-murderer Joseph Wood marked the fourth time this year that a state failed to dispatch a convict efficiently, according to the Constitution Project, a bipartisan legal group.3

    July 24, 2014

  • 072214 Diamond Llama 1.jpg Llama on the loose corralled in Missouri town

    A llama on the lam cruised Main Street Tuesday before it mistook a resident’s fenced backyard for a place to grab a meal and freshen up.

    July 22, 2014 2 Photos

  • NWS-HB0713-HowardMartin-004.jpg Airman laid to rest back home in Indiana six decades after death

    The mystery of what happened to a military transport plane that disappeared in the fall of 1952 into an Alaskan glacier was solved two years ago when a helicopter crew spotted the wreckage. But it took another two years to retrieve the remains of Airman Howard Miller and 16 other servicemen passengers. Saturday, Miller was laid to rest in his hometown of Elwood, Ind., with full military honors. Hundreds turned out for the funeral and burial services.

    July 13, 2014 2 Photos

  • New York to offer free lunch to all middle-school students

    New York's $75 billion spending plan for the fiscal year that began last week includes the first step toward offering free lunch for all 1.1 million students, expanding a program now reserved only for the city's poorest children.

    July 9, 2014

  • Screen Shot 2014-07-09 at 11.24.10 AM.png VIDEO: Pilot buys pizzas for storm-delayed travelers

    A Frontier Airlines pilot went above and beyond the call of duty when a recent flight from Washington, D.C. to Denver was diverted to Cheyenne, Wyoming due to bad weather.

    July 9, 2014 1 Photo

  • Why North Korean cheerleaders may soon descend on the South

    When you think of North Korea, "cheerleaders" may not be the first thing that springs to mind. The Hermit Kingdom is perhaps better known for less savory things like gulag-like labor camps and leadership purges.

    July 8, 2014

  • Screen Shot 2014-07-08 at 11.46.13 AM.png VIDEO: Foiled beach gear theft goes viral

    Video capturing a bizarre confrontation with two women allegedly attempting to steal beach gear on a Florida beach has gone viral.

    July 8, 2014 1 Photo

  • Screen Shot 2014-07-08 at 10.40.20 AM.png VIDEO: Sleeping fan suing Yankees, ESPN for $10M

    A fan caught on camera sleeping during a recent game at Yankee Stadium has filed suit against the Yankees and ESPN, claiming he suffered emotional distress when two announcers mocked him on the air.

    July 8, 2014 1 Photo

  • VIDEO: A boom in firework sales

    This year could be quite the boom for fireworks sales across the U.S. According to the American Pyrotechnics Association, or the APA, sales are already off to a good start.

    July 4, 2014

  • Happy birthday, America. Now legalize fireworks.

    Through the smoke of Roman candles and bottle rockets, the absurdity of Americans' obsession with do-it-yourself explosives is nonetheless clear: One day each year, we gather with neighbors, friends and loved ones to blow stuff up in our backyards. Go, U.S.A.!

    July 4, 2014