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Gut Bacteria Increase Pre-Diabetes Risk

  • Jessica Berman

Certain bacteria in the human gut seem to be associated with pre-diabetes, a condition marked by a constellation of risk factors that often precedes the on-set of full-blown type 2 diabetes in humans. The finding is part of an effort to discover the role of trillions of bacteria or microbiota that live in our bodies.

According to Brandi Cantarel, the number of bacteria living happily inside us outnumbers human cells by an astounding 10-1. Cantarel is a researcher at the Institute for Genome Science at the University of Maryland School of Medicine in Baltimore.

“With all that extra stuff, let’s say genetic material in our bodies that doesn’t come from us, it comes from other sources, we think it has to be doing something," said Cantarel. "Right?”

According to Cantarel, scientists believe there are over 7,000 strains of more than 1,000 different species of bacteria that live in the digestive tract, most of them in the gut or small intestine, which play a role in human health. Many of the trillions of microbes are helpful; without them, for example, we couldn’t digest food properly.

But experts say bacteria that are out of balance could be harmful. Researchers have identified 26 microbes that researchers say may be negatively associated with pre-diabetes or metabolic syndrome.

Investigators studied the gut microbiota of 310 members of the Old Order Amish, a closed-knit sect of Caucasian individuals living in rural Pennsylvania that emigrated from central Europe in the 1700’s in search of religious freedom. Experts say the Amish community has less genetic variation and a similar diet, making it easier to single out risk factors that might contribute to disease. They also take fewer medications.

Richard Horenstein, an endocrinologist at the University of Maryland, says stool samples were analyzed to identify gut microbiota in the Amish volunteers, all of whom were either overweight or obese with a range of metabolic syndrome indicators.

The samples, according to Horenstein, contained bacteria researchers were able to link to elevated blood pressure and total cholesterol levels, obesity and higher than normal levels of C-reactive protein, a marker for inflammation found to play a role in heart disease, cancer and other chronic diseases.

Horenstein says the participants fell into one of three distinct groups of gut microbiota. The greatest number of Amish had gut bacteria often seen in farm animals.

“And may even suggest the transmission of gut microbes across species, so from man to the animals or from the animals. And this is highly speculative," said Horenstein.

In the future, Horenstein says researchers might investigate a possible connection between human and animal microbiota. Another area of investigation, according to researchers, is to study the gut bacteria people in the general population who are of Central European descent for any similarities to the Amish population and to see whether gut microbes change over time, since most people tend to gain weight and develop chronic diseases as they age.

At this point, researchers say they cannot draw a direct connection between gut microbiota and pre-diabetes, so their findings cannot be used to help determine who is at risk for pre-diabetes.

An article on gut bacteria and metabolic syndrome is published in the journal PLoS One.