Can Gut Bacteria Imbalances Lead to Type 2 Diabetes?

The Gist

The bacteria residing in a person’s intestines—often referred to as gut bacteria or microflora—is much more like an environmental ecosystem than previously realized. As many as 100 trillion different bacteria may reside there, affecting everything from speed of digestion to nutrient absorption as well as whether or not the body becomes susceptible to chronic disease, such as type 2 diabetes.

Now, new research published this month in the scientific journal Nature suggests that a person’s likelihood for developing type 2 diabetes may be directly linked to imbalances in his or her microflora. The study offers clues as to how doctors may one day be able to use information about a

person’s gut bacteria in new, useful ways. This information could help uncover, for instance, an imbalanced metabolism well in advance of the development of a metabolic disorder like type 2 diabetes. Understanding imbalances of gut bacteria may also help doctors determine who will eventually develop the disease, as well as present new options for keeping these patients healthy.

In the study, which was conducted in China, scientists examined the gut bacteria of 345 people, of whom 171 were known type 2 diabetics. When comparing the microflora of both groups, scientists identified clear differences. These differences are biological indicators that may one day allow doctors to identify type 2 diabetes in people who have not yet developed symptoms of the disease.

In an ongoing effort to take a closer look at gut bacteria, the National Institutes of Health have begun a new five-year research investigation to examine and classify human microflora—known collectively as the microbiome—in a project called the Human Microbiome Project, an initiative comparable to the Human Genome Project. According to Princeton University microbiologist Bonnie Bassler, that research is a “fantastic” tool that enables greater understanding of the importance of bacteria in human health.

Similar studies conducted over the last few years have proved that the microbiome changes when a person’s eating habits change—for instance, when an obese person changes his or her diet. This finding is among the reasons why doctors believe that surgical procedures like bariatric surgery are useful for eliminating type 2 diabetes. This surgery immediately reduces the amount of food the body can absorb. However, the microbiome of the surgical patients also changes as a result of this procedure, and this is a potential contributing factor in reversal of the disease.  

The Expert Take

Another observation made clearer by the studies published in Nature was the fact that type 2 diabetics have a “more hostile” bacterial environment than healthy people. This is a potential reason why certain medications are not as useful for treating that group. Thus far, researchers have identified as many as 26 microbes that may be “negatively associated with pre-diabetes or metabolic syndrome,” according to Brandi Cantarel, a researcher at the Institute of Genome Science at the University of Maryland School of Medicine in Baltimore. Other experts, like Dr. Eric Triplett, professor of microbiology at the University of Florida, note that lean, healthy people also tend to have more diverse microflora.

The Takeaway

Continued research indicates that studying the microbiome and establishing criteria for what represents its good health may hold great promise in the fight against chronic disease. Understanding how exactly a person’s microbiome health relates to disease and how people react poorly or successfully to drugs and other treatments may lead to the elimination of many chronic conditions. Heart disease, certain cancers, irritable bowel syndrome, rheumatoid arthritis, multiple sclerosis, and even asthma and obesity may one day be more successfully treated in part because of information related to studying the microbiome.