Changes in Intestinal Bacteria Linked to Type 2 Diabetes
WEDNESDAY Sept. 26, 2012 -- People with type 2 diabetes have a different balance of bacteria in their digestive system than do people without the disease, new research indicates.
Chinese researchers conducted what's known as a metagenome-wide association study on microbes found in the gut to determine how they might be different in people with type 2 diabetes. They identified more than 60,000 markers, or indicators, associated with type 2 diabetes. And, they found that people with type 2 diabetes had an abundance of potentially harmful bacteria, and a reduction in the amount of helpful microbes.
What's not clear, however, is whether these changes can cause type 2 diabetes, or if these changes occur because of type 2 diabetes. Still, the researchers suggest that these findings offer clues that might help develop new treatments.
"I think our study provides many targets for disease prevention and treatment through gut microbiotia in the near future," said study senior author Jun Wang, executive director of the Beijing Genomics Institute in Shenzhen, China.
Results of the study were published in the Sept. 26 online edition of Nature.
Type 2 diabetes is a metabolic disorder that causes the body to use insulin inefficiently. Insulin is a hormone that helps blood sugar enter the body's cells to be used as fuel. In type 2 diabetes, the body may not use insulin properly (called insulin resistance), or there may not be enough insulin, according to the American Diabetes Association.
Symptoms include frequent infections, cuts or sores that are slow to heal, blurred vision, fatigue, tingling or numbness in the hands and feet, unusual thirst, frequent urination, unexpected weight loss and extreme hunger, according to the diabetes association.
The cause of type 2 diabetes is unknown, but is believed to be a combination of genetic and environmental factors. Recent research has suggested that an imbalance in the microbes in the intestines may play a role in type 2 diabetes.
To see what effect, if any, intestinal bacteria might play in type 2 diabetes, Wang and his team analyzed the genetic make-up of the gut microbes from 345 Chinese adults, some with and some without type 2 diabetes.
They found that the natural balance of "intestinal flora" was different in people with type 2 diabetes than in those without the disease. They found 60,000 markers related to type 2 diabetes, and concluded that some of these markers could be used to indicate a risk of type 2 diabetes before the disease develops.
The researchers said there's still a question as to whether or not these changes actually cause type 2 diabetes, and they are working on new studies to try to answer that question, according to Wang.
Several doctors not involved with the study said it's way too soon to know if the Chinese research will lead to useful insights and treatments.
"There's no way right now that you can say there's a cause-and-effect relationship. It could be that the patients with diabetes were treated with drugs that changed their gut flora. Or maybe they ate differently? This is an interesting hypothesis -- that gut bugs could influence diseases states -- but it's far from proven," said Dr. Stuart Weinerman, associate chief of the division of endocrinology at North Shore University Hospital/Long Island Jewish Medical Center in New Hyde Park, N.Y.
Dr. Joel Zonszein, director of the Clinical Diabetes Center at Montefiore Medical Center in New York City, agreed that this is an interesting study. But, he added that he doesn't believe there is one single cause of type 2 diabetes, such as a change in intestinal bacteria.
"Type 2 diabetes is a complex disease. I think the intestinal flora could be contributing to the pathogenesis of type 2 diabetes. The type of food we eat, the antibiotics we take, the preservatives in food all have a role in altering the microbial environment in the body. Small changes in certain patients may have tremendous impact," he said.
Learn more about type 2 diabetes and its causes from the U.S. National Library of Medicine.
Posted: September 2012