Type 2 Diabetes Linked to Gut Bacteria
Over the years, scientists have proposed a growing number of possible factors that could play a defining role in the development of type 2 diabetes. Among the latest addition to the possibilities are the bacteria living in your intestinal tract, also referred to as gut bacteria.
How could bacteria cause type 2 diabetes?
Bacteria is often associated with some type of infection, such as strep throat, tuberculosis, or even flesh-eating bacteria. The microorganisms referred to here are the more than three pounds of bacteria--some beneficial and some not--living in every person's intestinal tract (gut), and it is essential to keep those microorganisms in balance in order to maintain health.
Now a research team composed of scientists from the University of Copenhagen and the Beijing Genomics Institute have discovered that individuals with type 2 diabetes have a high amount of disease-causing bacteria (pathogens) in their gut.
According to Professor Karsten Kristiansen from the University of Copenhagen's Department of Biology, for now the discovery "demonstrates a correlation," and it has not yet been determined "whether the changes in gut bacteria can affect the development of type 2 diabetes or whether the changes simply reflect that the person is suffering from type 2 diabetes."
The international research team is part of the MetaHIT project, an effort funded by the European Commission, which set out to "establish associations between the genes of the human intestinal microbiota and our health and disease." This latest discovery of a correlation between gut bacteria and type 2 diabetes is an important addition to the research.
In the new study, researchers evaluated the gut bacteria of 345 individuals from China, of whom 171 had type 2 diabetes. Those with type 2 diabetes had a less balanced bacterial environment, which can reduce their ability to respond to different medications. In addition, they found clear indicators that may help in early diagnosis of the disease.
Other studies of gut bacteria and diabetes
A number of similar studies have examined the possible role of gut bacteria in type 2 diabetes. A 2011 report from Italy, published in the Annual Review of Medicine, discussed the "evidence connecting gut microflora to obesity and to type 1 and type 2 diabetes," including "increased nutrient absorption from the diet, prolonged intestinal transit time," and other potential links.
A prior study from the University of Copenhagen evaluated the fecal bacterial makeup of 36 adults, half of whom had type 2 diabetes. The investigators found several significant differences among varying types of bacteria between the two groups, including one class of bacteria that was "highly enriched" in diabetics and correlated with glucose.
Other research has examined the potential role of beneficial bacteria, or probiotics, in diabetes. In Current Pharmaceutical Design, researchers noted that "data obtained in experimental models and human subjects are in favour of the fact that changing the gut microbiota (with prebiotics and/or probiotics) may participate in the control of the development of metabolic diseases associated with obesity," and diabetes is one of those diseases.
Future studies will include transplanting the gut bacteria from individuals who have type 2 diabetes into mice to see if the animals develop diabetes, according to Professor Oluf Borbye Pedersen, University of Copenhagen and centre director at the Lundbeck Foundation Centre for Applied Medical Genomics in Personalised Disease Prediction, Prevention and Care.
Cani PD, Delzenne NM. The role of the gut microbiota in energy metabolism and metabolic disease. Current Pharmaceutical Design 2009; 15(13): 1546-58
Larsen N et al. Gut microbiota in human adults with type 2 diabetes differs from non-diabetic adults. PLoS One 2010 Feb 5; 5(2): e9085
Musso G et al. Interactions between gut microbiota and host metabolism predisposing to obesity and diabetes. Annual Review of Medicine 2011; 62:361-80
University of Copenhagen
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