Fighting Obesity With Gut Bacteria
February 10, 2013

Stomach Bacterium Responsible For Ulcers Could Help Combat Obesity

redOrbit Staff & Wire Reports - Your Universe Online

The same stomach microbe that experts believe is responsible for ulcers, gastric cancer, and other health issues could also help control a person´s body weight and glucose tolerance, researchers from the Virginia Bioinformatics Institute of Virginia Tech report in a recently-published study.

Helicobacter pylori, a microaerophilic bacterium found in the stomach, has been linked to the development of duodenal ulcers and stomach cancer, and has also been found in patients suffering from chronic gastritis and gastric ulcers. It is present in the stomachs of approximately half of the world´s population, though it is on the decline and that phenomenon could also be associated with the epidemic of obesity and diabetes in developed countries.

"H. pylori is the dominant member of the gastric microbiota and infects about half of the world population. While H. pylori infection can be associated with severe disease, it helps control chronic inflammatory, allergic, or autoimmune diseases," Josep Bassaganya-Riera, Director of the Nutritional Immunology and Molecular Medicine Laboratory and the Center for Modeling Immunity to Enteric Pathogens (MIEP) at Virginia Tech, said in a statement.

Writing in the peer-reviewed, open-access journal PLoS ONE, the investigators “demonstrated for the first time that gastric colonization with H. pylori exerts beneficial effects in mouse models of obesity and diabetes,” Bassaganya-Riera said.

They discovered that mice infected with the bacterium displayed less insulin resistance than both uninfected mice and mice infected with a more virulent strain of H. pylori.

Whether or not the infection is beneficial or harmful depends on the interaction between the genetic makeup of the bacterium and the immune response of the host, the researchers explained. H. pylori carrying the cytotoxin-associated gene pathogenicity island were harmful, they said, but whether or not the bacterium has an atypical island could be essential to human stomach microbiota, they added.

“The role of H. pylori as a pathogen does not provide an explanation as to why it has colonized the stomach of humans thousands of years. Our new findings suggest that H. pylori may provide important metabolic traits required to ameliorate diabetes that humans have not evolved on their own," Bassaganya-Riera said.

“To better understand the complex relationship between H. pylori and the human host and to better predict health outcomes, the Center for Modeling Immunity to Enteric Pathogens has developed computer models of the mechanisms by which H. pylori interacts with the host and new tools for investigating such interactions," he added.

Their findings suggest that overusing antibiotics, whether to treat misdiagnosed infections or supplementing livestock feed, could destroy beneficial bacteria. That, in turn, could play a role not just in obesity, but also in allergies, asthma, inflammatory bowel disease, or other ailments, according to the researchers.

"This novel finding underscores the complex relationship between H. pylori and humans, with effects not limited to the stomach, but more broadly affecting systemic inflammation and metabolism," explained Martin Blaser, a professor of internal medicine, chairman of the Department of Medicine, and professor of microbiology at New York University School of Medicine.