Note from CCFA's National Scientific Advisory Committee:
Please note that this study is based on a small sample that did not look at individual genes. However, it shows the enthusiasm that is building in this area and how the research community is using the available tools to move the field forward. This is a shared goal by The Crohn's & Colitis Foundation which is actively working to conduct research in this area. Through the Foundation's Microbiome Project, twins and family members are being analyzed in order to evaluate the role of genetics and environment. In addition, another CCFA-funded study is analyzing individual bacteria, and their groups and genes in much more detail. For more information see re-cap of study from American Gastroenterological Association News following the article.

Links seen between gut bacteria and disease: paper

Last Updated: 2010-03-03 15:23:31 -0400 (Reuters Health)

SHENZHEN, China (Reuters) - Some of the hundreds of bacteria found in the digestive systems of humans may be linked to specific diseases like cancer, diabetes and obesity, an international team of scientists said in a paper on Thursday.

Researchers, led by Chinese scientist Wang Jun, said in the latest issue of Nature they found more than 1,000 different species of bacteria in the human gut.

They said they had sequenced, or analyzed, the genes of each bacteria, creating the first genetic catalog of the organisms found in the human digestive system. Their research was based on analysis of stool samples from 124 people from Denmark and Spain.

Wang and his fellow researchers found several genes that may be linked to obesity and Crohn's disease, but he said more validation work was needed.

"Apart from helping you digest, these bacteria may also play a very important role in ... diseases like Crohn's disease, cancer, obesity," Wang, executive director of the Beijing Genomics Institute, said in an interview with Reuters.

"If you just tackle these bacteria, it is easier than treating the human body itself. If you find that a certain bug is responsible for a certain disease and you kill it, then you kill the disease," Wang said.

Crohn's disease is an inflammatory illness of the intestines which some believe may be caused by a variety of bacteria. Other possible causes include genetics and environmental factors.

Wang said creating the genetic catalog of all the bacteria in the human gut was only a beginning.

"There are a lot of unknown bacteria and pathogens that can cause different kinds of diseases," he said.

"So this is the first step and we have to study further to find concrete associations between these bacteria and human diseases, and then you can start learning how to get diagnosis, prognosis and then treatment," Wang said.

Wang and colleagues in China are working on a similar 120-sample study in Chinese hospitals.

"There are four groups: obese diabetics, obese non-diabetics, lean diabetics and lean non-diabetics. And we found some interesting bugs related to each type of diabetes," Wang said.

Re-cap of study from American Gastroenterological Association News: Scientists Complete Metagenome Of Gut Bacteria

The AP (3/4, Borenstein) reports, "The human gut is a virtual zoo, full of a wide variety of bacteria." In fact, the "average person's digestive tract" typically harbors "about 170 different bacteria species," according to a paper in Nature written by an international team of scientists. In an email, Jeroen Raes, from the "European Molecular Biology Laboratory in Germany, wrote, "I think it's important that people realize that we are not really human -- we are a walking colony of bacteria and they are crucial for our well being and health."

Altogether, scientists catalogued over 1,000 different species in samples collected from people in Spain and Denmark, Reuters (3/4, Lyn) reported. In an interview with Reuters, scientist Wang Jun, of the Beijing Genomics Institute, said, "Apart from helping you digest, these bacteria may also play a very important role in...diseases like Crohn's disease, cancer, obesity."

By study end, the group had created "what is called a metagenome, a combined genome of all the bacteria sequenced at once," BBC News (3/3, Walton) reported. And, "from looking at the genes, the researchers hope to be able to investigate how the flora changes when a person has a disease." The UK's Independent (3/4, Connor), also covered the story.