A growing body of research indicates that exposure to bacteria and viruses affects one’s likelihood for developing a number of chronic health conditions. Increasingly, scientists are uncovering proof that certain features of the human microbiome may be a root cause of obesity and Type 2 diabetes.
A new study published this week adds to this evidence, implicating staph bacteria as one potential cause of the disease.
For the study, published in the journal mBio, a team of microbiologists at the University of Iowa Carver College of Medicine exposed rabbits to the toxin produced by Staphylococcus aureus bacteria. The researchers found that exposure to high levels of this toxin caused the animals to develop symptoms of the disease, including insulin resistance, glucose intolerance and inflammation.
Their study suggests that drugs that eradicate or neutralize staph bacteria in the body may hold some promise as a treatment for Type 2 diabetes, which affects close to 30 million people in the U.S.
Because obesity is one of the common risk factors for the condition, the authors suggest extreme weight gain has a cascade effect: Obesity alters the microbiome and makes a person—or in this case, a rabbit—more susceptible to staph bacteria. Then a higher than normal exposure to toxins produced by the bacteria will trigger the disease.
Prior research has found that the toxins produced by staph bacteria disrupt normal immune system functioning, which can result in sepsis, inflammation of the heart and toxic shock, all of which can be fatal. But this new study shows staph toxins also affect fat cells.
To test their theory, the team of researchers measured the amount of staph bacteria and staph-related toxins on the skin of four patients with diabetes. They then calculated that the amount of toxins on the skin was in proportion to what triggered diabetes in the rabbits.
The researchers say they’re now turning their efforts toward developing a Type 2 diabetes vaccine that targets the toxins from staph colonization, which they believe could halt the development of diabetes in people at high risk. In addition, they are looking to study whether a topical gel that contains an antimicrobial agent to kill staph bacteria might also be effective.
Other research on the subject suggests altering microbiome diversity can halt Type 2 diabetes and reverse obesity. One study, published in May 2013 in the Proceedings of the National Academy of Sciences, found that mice that ate a high-fat diet had 100 times less the amount of a bacteria known as Akkermansia muciniphila than mice that ate a regular diet. When researchers fed the obese mice foods with this bacteria—along with foods that encourage microorganism growth—the mice lost weight and their body mass index ratio improved.