Microbiome

Gene map of body’s microbes is new health tool

Researchers said Wednesday they have produced the first comprehensive genetic map of the microbes that live in or on a healthy human body, laying the groundwork for possible new advances in research and in the diagnosis and treatment of disease.

The accomplishment — the result of a five-year, $173 million initiative called the Human Microbiome Project funded by the National Institutes of Health — stems from an effort to better understand bacteria and other organisms that play a critical role in processes ranging from digestion to infection.

Scientists know the body harbours trillions of such microorganisms — indeed, they outnumber human cells 10 to 1. But until now, they didn’t know what all the bacteria were, where they were and how they might differ from person to person, or from site to site on a single body.

“This is really a new vista in biology,” said Phillip Tarr, director of pediatric gastroenterology and nutrition at Washington University School of Medicine, St. Louis, and one of the leaders of the project, which involved some 200 researchers at 80 institutions.

The new genetic map should bolster research into a number of diseases whose onset is associated with a combination of genetic predisposition and changes to the body’s roster of bacteria.

“It’s likely this work will lead to new treatments for [the inflammatory bowel disorder] Crohn’s disease, new treatments for diabetes and metabolic diseases, new treatments for even other diseases, like eczema,” said Michael Fischbach, a biologist at the University of California, San Francisco, who wasn’t involved in the project….

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In good health? Thank your 100 trillion bacteria

For years, bacteria have had a bad name. They are the cause of infections, of diseases. They are something to be scrubbed away, things to be avoided.

But now researchers have taken a detailed look at another set of bacteria that may play even bigger roles in health and disease: the 100 trillion good bacteria that live in or on the human body.

No one really knew much about them. They are essential for human life, needed to digest food, to synthesize certain vitamins, to form a barricade against disease-causing bacteria. But what do they look like in healthy people, and how much do they vary from person to person?

In a new five-year federal endeavor, the Human Microbiome Project, which has been compared to the Human Genome Project, 200 scientists at 80 institutions sequenced the genetic material of bacteria taken from nearly 250 healthy people.

They discovered more strains than they had ever imagined — as many as a thousand bacterial strains on each person. And each person’s collection of microbes, the microbiome, was different from the next person’s. To the scientists’ surprise, they also found genetic signatures of disease-causing bacteria lurking in everyone’s microbiome. But instead of making people ill, or even infectious, these disease-causing microbes simply live peacefully among their neighbors.

The results, published on Wednesday in Nature and three PLoS journals, are expected to change the research landscape.

The work is “fantastic,” said Bonnie Bassler, a Princeton University microbiologist who was not involved with the project. “These papers represent significant steps in our understanding of bacteria in human health.”

Until recently, Dr Bassler added, the bacteria in the microbiome were thought to be just “passive riders.” They were barely studied, microbiologists explained, because it was hard to know much about them. They are so adapted to living on body surfaces and in body cavities, surrounded by other bacteria, that many could not be cultured and grown in the lab. Even if they did survive in the lab, they often behaved differently in this alien environment. It was only with the advent of relatively cheap and fast gene sequencing methods that investigators were able to ask what bacteria were present.

Examinations of DNA sequences served as the equivalent of an old-time microscope, said Curtis Huttenhower of the Harvard School of Public Health, an investigator for the microbiome project. They allowed investigators to see — through their unique DNA sequences — footprints of otherwise elusive bacteria.

The work also helps establish criteria for a healthy microbiome, which can help in studies of how antibiotics perturb a person’s microbiome and how long it takes the microbiome to recover.

In recent years, as investigators began to probe the microbiome in small studies, they began to appreciate its importance. Not only do the bacteria help keep people healthy, but they also are thought to help explain why individuals react differently to various drugs and why some are susceptible to certain infectious diseases while others are impervious. When they go awry they are thought to contribute to chronic diseases and conditions like irritable bowel syndrome, asthma, even, possibly, obesity.

Humans, said Dr David Relman, a Stanford microbiologist, are like coral, “an assemblage of life-forms living together.”

Dr Barnett Kramer, director of the division of cancer prevention at the National Cancer Institute, who was not involved with the research project, had another image. Humans, he said, in some sense are made mostly of microbes. From the standpoint of our microbiome, he added, “we may just serve as packaging.”…..

New York Times: Read more

Human Microbiome Project DACC – Home

www.hmpdacc.org/

The Human Microbiome Project (HMP), launched by the National Institutes of Health Roadmap for Medical Research, is designed to fuel research into the

IHMC: The International Human Microbiome Consortium

www.human-microbiome.org/

The goal of the IMHC is to work under a common set of principles and policies to study and understand the role of the human microbiome in the maintenance of

Mapping the healthy human microbiome

www.sciencedaily.com/releases/2012/06/120613133140.htm

Human beings are ecosystems on two legs, each of us carrying enough microbes to outnumber our human cells by 10 to 1 and our genes by