U. FLORIDA (US)—The variety of bacteria in the digestive tract is strongly linked to whether a child will develop type 1 diabetes, according to a new study.
The connection could give doctors an early test for the condition and lead to new treatment for the disease.
There appears to be little or no genetic element to the condition, formerly known as juvenile diabetes, researchers say.
Only 15 percent of those who develop it have an immediate family member with the condition, meaning there is likely a trigger somewhere in the patient’s environment.
The trigger may be linked to bacteria that live in the digestive tracts, which are relatively sterile at birth.
Most people build and maintain a healthy variety of microbes in the gut that are essential to health, helping to break down food while offering an extra layer of protection for the digestive system.
The new research shows that type 1 diabetic children lose this balance of bacteria. While healthy children all have similar microbial mixes, the diabetic children all have erratic combinations with less overall variety.
“Like the famous first line of Tolstoy’s Anna Karenina, ‘All happy families are alike; each unhappy family is unhappy in its own way,’ ” says Eric Triplett, chairman of the department of microbiology and cell science at the University of Florida.
Details of the study are available online in The International Society of Microbial Ecology Journal.
The research tracked the gut bacteria of eight Finnish children—four of whom developed diabetes and four who did not—by using cutting-edge, high-speed genetic analysis to identify and quantify the bacteria present in the children’s bodily waste.
The uniformity of Finland’s gene pool, along with a higher prevalence of type 1 diabetes, makes the Finnish population ideal for genetic research on the condition, says Mark Atkinson, a type 1 diabetes researcher in the department of pathology, immunology, and laboratory medicine.
As the diabetic children’s disease progressed, so did the irregular makeup of their gut bacteria.
It’s not clear why the bacteria populations skew in some people. It’s also not entirely clear, Atkinson says, how that unbalanced mix contributes to the disease, which occurs when the body’s own immune system destroys insulin-producing cells in the patient’s pancreas.
One theory holds that the lack of a stable bacterial mix leaves the wall of the digestive tract weak allowing for unusually large and complex proteins to enter the bloodstream that are then detected by the immune system, causing it to overact and essentially “misfire.”
In this way, the researchers say, an unstable microbial mix may contribute to other immunological diseases, such as Crohn’s disease, celiac disease, and multiple sclerosis. Recent research has also shown that gut bacteria are also linked to some cases of obesity.
The bacterial mix seems to begin becoming unstable before the patient begins to show signs of the condition. Tests to evaluate gut bacteria levels could be a useful early indication of disease, and could give doctors an early jump on treatment.
Previous studies using mice have shown that introducing beneficial bacteria—such as the kind commonly found in active-culture yogurt—can help correct the microbial mix and help stave off the onset of type 1 diabetes.
“It won’t be as easy as feeding a patient yogurt,” Triplett says. “But if we could develop a system of profiling someone’s gut microbiome, then maybe we can develop a system for correcting or at least modifying it, as well.”
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